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==Overview==
==Overview==
Today, lung cancer is one of the leading causes of death worldwide, killing over 1 million people per year but it was not always that way. Primary lung cancer can be classified into two main categories: [[small cell lung cancer]] (~15%) and [[non small cell lung cancer]] (~85%). The pathophysiology consists of [[genetics]], [[smoking]], [[radon]] gas, [[asbestos]], [[viruses]], [[infection]], and [[inflammation]]. The main causes of any cancer include [[carcinogens]] (such as those in [[tobacco smoke]]), [[ionizing radiation]], and [[viral infection]]. Lung cancer may be differentiated from other diseases that cause [[hemoptysis]], [[cough]], [[dyspnea]], [[wheeze]], [[chest pain]], [[dysphonia]], [[dysphagia]], unexplained [[weight loss]], unexplained [[loss of appetite]], and [[fatigue]] such as [[pneumonia]], [[bronchitis]], [[metastatic cancer]] from a non-thoracic primary site, infectious granuloma, [[pulmonary tuberculosis]], tracheal [[tumors]], and a [[Thyroid mass causes|thyroid mass]]. Worldwide, lung cancer is the most common cancer in terms of both [[incidence]] and [[mortality]] with 1.35 million new cases per year and 1.18 million deaths. Lung cancer is the deadliest type of cancer for both men and women. Each year, more people die of lung cancer than [[Breast Cancer|breast]], [[Colorectal cancer|colon]], and [[Prostate cancer|prostate cancers]] combined. Lung cancer screening is a strategy used to identify early lung cancer in people, before they develop symptoms. Screening refers to the use of medical tests to detect disease in asymptomatic people. Screening studies for lung cancer have only been done in high risk populations, such as smokers and workers with occupational exposure to certain substances. The majority of lung cancers present with advanced disease because the symptoms tend to occur later in the course of the disease. [[Lung cancer staging]] is an assessment of the degree of spread of the cancer from its original source. It is an important factor affecting the [[prognosis]] and potential treatment of lung cancer. Many of the symptoms of lung cancer ([[bone pain]], [[fever]], [[weight loss]]) are nonspecific; in the elderly, these may be attributed to comorbid illness. Generally, the most common signs of lung cancer are decreased/[[Breath sounds|absent breath sounds]], [[wheeze]], [[chest pain]], [[emaciation]], [[lethargy]], and [[pallor]]. The laboratory findings associated with lung cancer are the following: [[neutropenia]], [[hyponatremia]], [[hypokalemia]], [[hypercalcemia]], [[respiratory acidosis]], [[hypercarbia]], [[hypoxia]], and tumor cells in sputum and [[Pleural effusion|pleural effusion cytology]]. Performing a [[Chest X-ray|chest x-ray]] is the first step if a patient reports symptoms that may be suggestive of lung cancer. [[CT scans]] help stage the lung cancer. [[MRI]] is useful for the evaluation of a patient with [[spinal cord compression]], superior sulcus tumors, and [[Brachial plexus|brachial plexus tumors]]. A [[Needle biopsy|transthoracic needle biopsy]] and a [[bronchoscopy]] are conducted to diagnose lung cancer. Other diagnostic tests include [[Scintigraphy|bone scintigraphy]], [[PET scan]], and molecular tests. The medical therapy for lung cancer consists of [[surgery]], [[radiation therapy]], [[chemotherapy]], and targeted therapy. Lung cancer surgery involves the surgical excision of cancer tissue from the lung. [[Smoking cessation]] and avoidance of second hand smoking are the most important measures for the prevention of lung cancer. Secondary prevention for lung cancer consists of [[smoking cessation]] and [[Screening (medicine)|screening]].
Prior to the introduction of [[cigarette]] [[smoking]] and industrial [[carcinogens]], lung cancer was thought to be a [[rare disease]]. Of all the [[tumors]] detected on [[autopsy]], lung cancer accounted for only 1% of [[cancers]] in the 1800s. The majority of cases of lung cancer were associated with occupational hazards due to [[radon]] exposure. The association between lung cancer and [[smoking]] was not defined until the mid-20th century. Primary lung cancers may be [[Classification|classified]] into [[small cell lung cancer]] (~15%) and [[non small cell lung cancer]] (~85%).  [[Non small cell lung cancer]] are a [[heterogeneous]] group of lung cancers that are often grouped together because they share similar clinical features (e.g. [[prognosis]] and management). The 2015 [[World Health Organization|WHO]] [[Histology|histological]] [[classification]] of [[tumors]] of the [[lung]] categorized [[lung]] [[tumors]] into [[malignant]] [[epithelial]] [[tumors]], [[benign]] [[epithelial]] [[tumors]], [[Lymphoproliferative disorders|lymphoproliferative tumors]], miscellaneous [[tumors]], and [[metastatic]] [[tumors]]. The [[pathophysiology]] of lung cancer includes both [[genetic]] and [[Environmental factor|environmental factors]]. [[Causality]] of the majority of lung cancer is linked to [[Tobacco|tobacco usage.]] [[Carcinogen|Carcinogenic]] effects of [[tobacco smoking]] may result in [[DNA]] mis-replication and [[mutation]]. [[Smoking]] starts a [[cascade]] of events that leads to [[cancer]] development, even decades after [[smoking cessation]]. Besides [[Smoking|smokers]], [[Patient|patients]] with the history of prior [[Respiratory tract neoplasm|respiratory tract]] or [[gastrointestinal tract cancer]] comprise a high-risk population. Other [[Environmental factor|environmental factors]] include [[radon]], [[asbestos]], [[viral infections]], and states of [[Pulmonary inflammation|chronic lung inflammation]], all of which may [[Predisposition|predispose]] to [[cellular]] damage and [[DNA mutations]] that [[Predisposition|predispose]] to the development of lung cancers. The direct cause of lung cancer is [[DNA mutations]] that often result in either activation of [[Proto-oncogene|proto-oncogenes]] (e.g. '''[[KRAS|K-RAS]]''') or the inactivation of [[Tumor suppressor gene|tumors suppressor genes]] (e.g. '''[[TP53]]''') or both. The risk of these [[genetic mutations]] may be increased following exposure to environmental insults. Lung cancer must be differentiated from other conditions that cause [[hemoptysis]], [[cough]], [[dyspnea]], [[Wheeze|wheezing]], [[chest pain]], [[dysphonia]], [[dysphagia]], unexplained [[weight loss]], unexplained [[loss of appetite]], and [[fatigue]]. These conditions include [[pneumonia]], [[bronchitis]], [[metastatic cancer]] from a non-[[Chest|thoracic]] primary site, [[infectious]] [[granuloma]], [[Tuberculosis|pulmonary tuberculosis]], [[Trachea|tracheal]] [[Tumor|tumors]], and a [[thyroid]] mass. Lung cancer is the most common cause of [[cancer]]-associated [[mortality]] and the second most common type of [[cancer]] among both genders. Individuals > 50 years of age who have a history of [[smoking]] are at increased risk. Historically, the [[incidence]] of lung cancer is significantly higher among [[Male|males]] compared to [[Female|females]]. This increased ratio is thought to be attributed to the increased rates of [[smoking]] among [[Male|men]]. However, more [[Female|women]] are being [[Diagnosis|diagnosed]] with lung cancer due to the increased rate of [[smoking]] among [[Female|women]]. In 2014, the [[incidence]] of [[lung cancer]] in the United States was approximately 70 cases per 100,000. The most potent [[risk factor]] in the development of lung cancer is [[tobacco]] [[smoking]]. Other [[Risk factor|risk factors]] include [[Passive smoking|second hand smoke]], [[air pollution]], [[family history]] of lung cancer, [[radiation therapy]] to the [[chest]], and exposure to [[radon]], [[asbestos]] and other [[chemical]] [[carcinogens]]. Lung cancer [[Screening (medicine)|screening]] is a strategy used to identify early lung cancer in people, before they develop [[Symptom|symptoms]]. [[Screening (medicine)|Screening]] refers to the use of [[Medicine|medical]] [[Test|tests]] to detect [[disease]] in [[asymptomatic]] people. [[Screening (medicine)|Screening]] studies for lung cancer have only been done in high risk populations, such as [[Smoking|smokers]] and workers with occupational exposure to certain substances. This is because [[radiation exposure]] from [[Screening (medicine)|screening]] could actually induce [[carcinogenesis]] in a small percentage of [[Screening|screened]] subjects, so this risk should be mitigated by a (relatively) high [[prevalence]] of lung cancer in the population being [[Screening|screened]]. A [[pulmonary nodule]] larger than 5 - 6 mm is considered a positive result for [[Screening (medicine)|screening]] with [[x-ray]] or [[computed tomography]]. The majority of lung cancers present with advanced [[disease]] because the [[symptoms]] tend to occur later in the course of the [[disease]]. [[Patient|Patients]] experience non-specific [[Symptom|symptoms]] such as [[cough]], [[hemoptysis]], [[dyspnea]], [[chest pain]], [[Dysphonia|difficulty speaking]], [[Dysphagia|difficulty swallowing]], [[lack of appetite]], [[weight loss]], and [[fatigue]] from 3 weeks to 3 months before seeking medical attention. There are a variety of [[complications]] associated with lung cancer, such as [[pleural effusion]], [[leg weakness]], [[paresthesias]], [[Urinary bladder|bladder]] dysfunction, [[seizures]], [[hemiplegia]], [[cranial nerve palsies]], [[confusion]], [[personality changes]], [[Skeleton|skeletal]] [[pain]], [[pleuritic pain]], [[atelectasis]], and [[bronchopleural fistula]]. The [[prognosis]] of lung cancer is poor if [[Diagnosis|diagnosed]] at the advanced stages. [[Chest]] [[Computed tomography|CT scan]] is the modality of choice in the [[diagnosis]] of lung cancer. Findings on [[Computed tomography|CT scan]] suggestive of lung cancer include a [[Pulmonary nodule|solitary pulmonary nodule]], centrally located [[Tumor|masses]], [[Mediastinum|mediastinal]] [[Invasive (medical)|invasion]] [[Computed tomography|CT scans]] help [[Cancer staging|stage]] the lung cancer. A [[Computed tomography|CT scan]] of the [[abdomen]] and [[brain]] can help visualize the common sights of [[Metastasis|metastases]] such as [[Adrenal gland|adrenal glands]], [[liver]], and [[brain]]. [[Computed tomography|CT scans]] [[Diagnosis|diagnose]] lung cancer by providing [[anatomical]] detail to locate the [[tumor]], demonstrating proximity to the nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]]. Common symptoms of lung cancer include [[Dyspnea|difficulty breathing]], [[hemoptysis]], [[Chronic cough|chronic coughing]], [[chest pain]], [[Cachexia|weakness and wasting]], [[Dysphonia|difficulty speaking]], and [[Symptom|symptoms]] related to [[paraneoplastic syndromes]]. Common [[physical examination]] findings of lung cancer include decreased/absent [[breath sounds]], [[pallor]], low-grade [[fever]], and [[tachypnea]]. The [[Medical laboratory|laboratory]] findings associated with lung cancer are the following [[neutropenia]], [[hyponatremia]], [[hypokalemia]], [[hypercalcemia]], [[respiratory acidosis]], [[hypercarbia]], [[hypoxia]], and [[Tumor cell|tumor cells]] in [[sputum]] and [[pleural effusion]] [[cytology]]. Performing a [[chest x-ray]] is the first step if a [[patient]] reports [[Symptom|symptoms]] that may be suggestive of lung cancer. Lung cancers are usually detected on a routine [[Chest X-ray|chest x-ray]] in a person experiencing no [[Symptom|symptoms]]. There are no [[echocardiography]]/[[ultrasound]] findings associated with lung cancer. [[Chest]] [[Computed tomography|CT scan]] is the modality of choice in the [[diagnosis]] of lung cancer. Findings on [[Computed tomography|CT scan]] suggestive of lung cancer include a [[Pulmonary nodule|solitary pulmonary nodule]], centrally located [[Tumor|masses]], [[Mediastinum|mediastinal]] [[Invasive (medical)|invasion]] [[Computed tomography|CT scans]] help [[Cancer staging|stage]] the lung cancer. A [[Computed tomography|CT scan]] of the [[abdomen]] and [[brain]] can help visualize the common sights of [[Metastasis|metastases]] such as [[Adrenal gland|adrenal glands]], [[liver]], and [[brain]]. [[Computed tomography|CT scans]] [[Diagnosis|diagnose]] lung cancer by providing [[anatomical]] detail to locate the [[tumor]], demonstrating proximity to the nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]]. The [[Indication (medicine)|indication]] of [[Magnetic resonance imaging|MRI]] in lung cancer is when there is a suspicion of [[spinal cord]] canal [[Invasive (medical)|invasion]] and/or in the presence of [[pancoast tumor]] ([[Sulcus (anatomy)|superior sulcus]] [[tumor]]) and [[brachial plexus]] [[Tumor|tumors]]. There are no other [[imaging]] findings associated with lung cancer. Other [[Diagnosis|diagnostic]] studies include [[bone]] [[scintigraphy]], [[PET scan]], and [[molecular]] [[Test|tests]]. [[Medical]] [[therapy]] for lung cancer consists of [[radiation therapy]], [[chemotherapy]], and targeted [[therapy]]. Lung cancer [[surgery]] involves the [[Excision|surgical excision]] of the [[Cancer|cancerous]] [[Tissue (biology)|tissue]]. It is used mainly in [[non-small cell lung cancer]] with the intention of [[Cure|curing]] the [[patient]]. Effective measures for the [[Prevention (medical)|primary prevention]] of lung cancer include [[smoking cessation]] and avoidance of [[Passive smoking|second hand smoking]]. Lifestyle changes, such as [[Health|healthy]] [[Diet (nutrition)|diet]] rich with [[Fruit|fruits]] and [[Vegetable|vegetables]] and regular [[Physical exercise|exercise]], might decrease the risk of developing cancer in general. [[Prevention (medical)|Secondary prevention]] of lung cancer consists of [[smoking cessation]] and [[Screening (medicine)|screening]]. Secondary chemoprevention focuses on blocking the development of lung cancer in individuals in whom a [[precancerous]] [[lesion]] has been detected.


==Historical Perspective==
==Historical Perspective ==
Prior to the introduction of [[cigarette smoking]] and industrial [[carcinogens]], lung cancer was thought to be a rare disease. Of all tumors detected upon [[autopsy]], lung cancer accounted for only 1% of cancers in the 1800s. The majority of cases of lung cancer were associated with occupational hazards due to [[Radon|radon exposure]]. The association between lung cancer and [[smoking]] was not defined until the mid-20th century. Today, lung cancer is one of the leading causes of death worldwide, killing over 1 million people per year but it was not always that way. Approximately 150 years ago, lung cancer was actually a very rare disease. At the Institute of Pathology of the University of Dresden in Germany, lung cancer represented only 1% of all cancers seen at [[autopsy]]. Lung cancer steadily rose from this point on and in 1918 the percentage had risen to nearly 10% and by 1927, it represented more than 14% of all cancers. Around this time period, the disease had a life expectancy from about 6 months to 2 years and in most cases, the afflicted individual had long term [[chronic bronchitis]].
Prior to the introduction of [[cigarette]] [[smoking]] and industrial [[carcinogens]], lung cancer was thought to be a [[rare disease]]. Of all the [[tumors]] detected on [[autopsy]], lung cancer accounted for only 1% of [[cancers]] in the 1800s. The majority of cases of lung cancer were associated with occupational hazards due to [[radon]] exposure. The association between lung cancer and [[smoking]] was not defined until the mid-20th century.


==Classification==
==Classification==
Primary lung cancers may be classified into two main categories: [[small cell lung cancer]] (~15%) and [[non small cell lung cancer]] (~85%). [[Non small cell lung cancer]] are a heterogenous group of lung cancers that are often grouped together because they share similar clinical features (e.g. [[prognosis]] and management). The 2004 WHO histological classification of tumors of the lung categorized lung tumors into [[malignant]] epithelial tumors, [[benign]] epithelial tumors, [[Lymphoproliferative|lymphoproliferative tumors]], miscellaneous tumors, and [[Metastatic tumor|metastatic tumors]].
Primary lung cancers may be [[Classification|classified]] into [[small cell lung cancer]] (~15%) and [[non small cell lung cancer]] (~85%). [[Non small cell lung cancer]] are a [[heterogeneous]] group of lung cancers that are often grouped together because they share similar clinical features (e.g. [[prognosis]] and management). The 2015 [[World Health Organization|WHO]] [[Histology|histological]] [[classification]] of [[tumors]] of the [[lung]] categorized [[lung]] [[tumors]] into [[malignant]] [[epithelial]] [[tumors]], [[benign]] [[epithelial]] [[tumors]], [[Lymphoproliferative disorders|lymphoproliferative tumors]], miscellaneous [[tumors]], and [[metastatic]] [[tumors]].


==Pathophysiology==
==Pathophysiology==
The pathophysiology of lung cancer includes both [[genetic]] and [[Environmental factor|environmental factors]]. [[Genetic mutations]], namely mutations in K-ras oncogene and [[TP53|TP53 tumor-suppressor gene]], are associated with the development of lung cancers. [[Environmental factor|Environmental factors]] often include [[smoking]] (most important [[carcinogen]]), [[radon]], [[asbestos]], [[viral infections]], and states of chronic lung inflammation, all of which may predispose to cellular damage and [[DNA mutations]] that predispose to the development of lung cancers.
The [[pathophysiology]] of lung cancer includes both [[genetic]] and [[Environmental factor|environmental factors]]. [[Causality]] of the majority of lung cancer is linked to [[Tobacco|tobacco usage.]] [[Carcinogen|Carcinogenic]] effects of [[tobacco smoking]] may result in [[DNA]] mis-replication and [[mutation]]. [[Smoking]] starts a [[cascade]] of events that leads to [[cancer]] development, even decades after [[smoking cessation]]. Besides [[Smoking|smokers]], [[Patient|patients]] with the history of prior [[Respiratory tract neoplasm|respiratory tract]] or [[gastrointestinal tract cancer]] comprise a high-risk population. Other [[Environmental factor|environmental factors]] include [[radon]], [[asbestos]], [[viral infections]], and states of [[Pulmonary inflammation|chronic lung inflammation]], all of which may [[Predisposition|predispose]] to [[cellular]] damage and [[DNA mutations]] that [[Predisposition|predispose]] to the development of lung cancers.


==Causes==
==Causes==
The direct cause of lung cancers is [[DNA mutations]] that often result in either activation of [[Proto-oncogene|proto-oncogenes]] (e.g. K-RAS) or the inactivation of [[Tumor suppressor gene|tumor suppressor genes]] (e.g. [[TP53]]) or both. The risk of these [[genetic mutations]] may be increased following exposure to environmental components.
The direct cause of lung cancer is [[DNA mutations]] that often result in either activation of [[Proto-oncogene|proto-oncogenes]] (e.g. '''[[KRAS|K-RAS]]''') or the inactivation of [[Tumor suppressor gene|tumors suppressor genes]] (e.g. '''[[TP53]]''') or both. The risk of these [[genetic mutations]] may be increased following exposure to environmental insults.


==Differential Diagnosis==
==Differential Diagnosis==
Lung cancer must be differentiated from other diseases that cause [[hemoptysis]], [[cough]], [[dyspnea]], [[wheeze]], [[chest pain]], [[dysphonia]], [[dysphagia]], unexplained [[weight loss]], unexplained [[loss of appetite]], and [[fatigue]] such as [[pneumonia]], [[bronchitis]], [[metastatic cancer]] from a non-thoracic primary site, infectious granuloma, [[pulmonary tuberculosis]], [[tracheal tumors]], and a [[Thyroid mass causes|thyroid mass]].
Lung cancer must be differentiated from other conditions that cause [[hemoptysis]], [[cough]], [[dyspnea]], [[Wheeze|wheezing]], [[chest pain]], [[dysphonia]], [[dysphagia]], unexplained [[weight loss]], unexplained [[loss of appetite]], and [[fatigue]]. These conditions include [[pneumonia]], [[bronchitis]], [[metastatic cancer]] from a non-[[Chest|thoracic]] primary site, [[infectious]] [[granuloma]], [[Tuberculosis|pulmonary tuberculosis]], [[Trachea|tracheal]] [[Tumor|tumors]], and a [[thyroid]] mass.


==Epidemiology and Demographics==
==Epidemiology and Demographics==
Lung cancer is the deadliest cancer and the second most common cancer among both genders. Older individuals > 50 years of age who have a history of [[smoking]] are at increased risk. Historically, the incidence of lung cancer is significantly higher among males compared to females. This increased ratio is thought to be attributed to the increased rates of smoking among men. However, more women are being diagnosed with lung cancer due to the increased rate of smoking among women. In 2014, the incidence of [[lung cancer]] in the United States for 2014 was approximately 70 cases per 100,000.
Lung cancer is the most common cause of [[cancer]]-associated [[mortality]] and the second most common type of [[cancer]] among both genders. Individuals > 50 years of age who have a history of [[smoking]] are at increased risk. Historically, the [[incidence]] of lung cancer is significantly higher among [[Male|males]] compared to [[Female|females]]. This increased ratio is thought to be attributed to the increased rates of [[smoking]] among [[Male|men]]. However, more [[Female|women]] are being [[Diagnosis|diagnosed]] with lung cancer due to the increased rate of [[smoking]] among [[Female|women]]. In 2014, the [[incidence]] of [[lung cancer]] in the United States was approximately 70 cases per 100,000.


==Risk Factors==
==Risk Factors==
The most potent risk factor in the development of lung cancer is [[smoking]]. Other risk factors include [[secondhand smoke]], [[air pollution]], family history of lung cancer, [[radiation therapy]] to the chest, [[Radon|radon exposure]], [[asbestos]] exposure and exposure to other chemical [[carcinogens]].
The most potent [[risk factor]] in the development of lung cancer is [[tobacco]] [[smoking]]. Other [[Risk factor|risk factors]] include [[Passive smoking|second hand smoke]], [[air pollution]], [[family history]] of lung cancer, [[radiation therapy]] to the [[chest]], and exposure to [[radon]], [[asbestos]] and other [[chemical]] [[carcinogens]].


==Screening==
==Screening==
Lung cancer screening is a strategy used to identify early lung cancer in people, before they develop symptoms. [[Screening (medicine)|Screening]] refers to the use of medical tests to detect disease in asymptomatic people. Screening studies for lung cancer have only been done in high risk populations, such as smokers and workers with [[Occupational exposure limit|occupational exposure]] to certain substances. This is because [[radiation exposure]] from screening could actually induce [[carcinogenesis]] formation in a small percentage of screened subjects, so this risk should be mitigated by a (relatively) high [[prevalence]] of lung cancer in the population being screened. A [[pulmonary nodule]] larger than 5 to 6 mm is considered a positive result for screening with [[x-ray]] or [[computed tomography]].
Lung cancer [[Screening (medicine)|screening]] is a strategy used to identify early lung cancer in people, before they develop [[Symptom|symptoms]]. [[Screening (medicine)|Screening]] refers to the use of [[Medicine|medical]] [[Test|tests]] to detect [[disease]] in [[asymptomatic]] people. [[Screening (medicine)|Screening]] studies for lung cancer have only been done in high risk populations, such as [[Smoking|smokers]] and workers with occupational exposure to certain substances. This is because [[radiation exposure]] from [[Screening (medicine)|screening]] could actually induce [[carcinogenesis]] in a small percentage of [[Screening|screened]] subjects, so this risk should be mitigated by a (relatively) high [[prevalence]] of lung cancer in the population being [[Screening|screened]]. A [[pulmonary nodule]] larger than 5 - 6 mm is considered a positive result for [[Screening (medicine)|screening]] with [[x-ray]] or [[computed tomography]].


==Natural History, Complications, and Prognosis==
==Natural History, Complications, and Prognosis==
The majority of lung cancers present with advanced disease because the symptoms tend to occur later in the course of the disease. The patient experiences non-specific symptoms such as [[cough]], [[hemoptysis]], [[dyspnea]], [[Chest pain|chest pain,]] [[dysphonia]], [[dysphagia]], [[fatigue]], [[lack of appetite]], [[weight loss]], and fatigue from 3 weeks to 3 months before seeking medical attention. There are a variety of complications associated with lung cancer such as pleural effusion, leg weakness paresthesias, bladder/bladder dysfunction, seizures, hemiplegia, cranial nerve palsies, confusion, personality changes, skeletal pain, and/or pleuritic pain, [[atelectasis]], and/or [[bronchopleural fistula]]. The prognosis of lung cancer is poor if diagnosed during the advanced stages.
The majority of lung cancers present with advanced [[disease]] because the [[symptoms]] tend to occur later in the course of the [[disease]]. [[Patient|Patients]] experience non-specific [[Symptom|symptoms]] such as [[cough]], [[hemoptysis]], [[dyspnea]], [[chest pain]], [[Dysphonia|difficulty speaking]], [[Dysphagia|difficulty swallowing]], [[lack of appetite]], [[weight loss]], and [[fatigue]] from 3 weeks to 3 months before seeking medical attention. There are a variety of [[complications]] associated with lung cancer, such as [[pleural effusion]], [[leg weakness]], [[paresthesias]], [[Urinary bladder|bladder]] dysfunction, [[seizures]], [[hemiplegia]], [[cranial nerve palsies]], [[confusion]], [[personality changes]], [[Skeleton|skeletal]] [[pain]], [[pleuritic pain]], [[atelectasis]], and [[bronchopleural fistula]]. The [[prognosis]] of lung cancer is poor if [[Diagnosis|diagnosed]] at the advanced stages.


==Staging==
==Diagnosis==
The staging of lung cancer is based on the TNM classification of lung cancer. Lung [[cancer staging]] is an assessment of the degree of spread of the cancer from its original source. It is an important factor affecting the [[prognosis]] and potential treatment of lung cancer. Non-small cell lung carcinoma is staged from IA ("one A", best prognosis) to IV ("four", worst prognosis). [[Small cell lung carcinoma]] is classified as limited ''stage'' and ''extensive stage''


==History and Symptoms==
=== Diagnostic Study of Choice ===
Many of the symptoms of lung cancer (bone pain, fever, weight loss) are nonspecific; in the elderly, these may be attributed to comorbid illness. In many patients, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Common sites of metastasis include the bone, such as the spine (causing back pain and occasionally spinal cord compression), the liver and the brain. About 10% of people with lung cancer do not have symptoms at diagnosis; these cancers are incidentally found on routine chest x-rays.
[[Chest]] [[Computed tomography|CT scan]] is the modality of choice in the [[diagnosis]] of lung cancer. Findings on [[Computed tomography|CT scan]] suggestive of lung cancer include a [[Pulmonary nodule|solitary pulmonary nodule]], centrally located [[Tumor|masses]], [[Mediastinum|mediastinal]] [[Invasive (medical)|invasion]] [[Computed tomography|CT scans]] help [[Cancer staging|stage]] the lung cancer. A [[Computed tomography|CT scan]] of the [[abdomen]] and [[brain]] can help visualize the common sights of [[Metastasis|metastases]] such as [[Adrenal gland|adrenal glands]], [[liver]], and [[brain]]. [[Computed tomography|CT scans]] [[Diagnosis|diagnose]] lung cancer by providing [[anatomical]] detail to locate the [[tumor]], demonstrating proximity to the nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]].


==Physical Examination==
===History and Symptoms===
Generally, the most common signs of lung cancer are decreased/absent breath sounds, wheeze, chest pain, emaciation, lethargy, and pallor. Other signs include metastases to the liver, brain, and adrenal glands (Cushing's syndrome).
Common symptoms of lung cancer include [[Dyspnea|difficulty breathing]], [[hemoptysis]], [[Chronic cough|chronic coughing]], [[chest pain]], [[Cachexia|weakness and wasting]], [[Dysphonia|difficulty speaking]], and [[Symptom|symptoms]] related to [[paraneoplastic syndromes]].
 
===Physical Examination===
Common [[physical examination]] findings of lung cancer include decreased/absent [[breath sounds]], [[pallor]], low-grade [[fever]], and [[tachypnea]].


==Diagnostic Studies==
==Diagnostic Studies==
=== Diagnostic study of choice ===
=== Diagnostic study of choice ===
Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include, a solitary pulmonary nodule, centrally located masses, mediastinal invasion CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases: adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum.
[[CT scan|Chest CT scan]] is the modality of choice in the diagnosis of lung cancer. Findings on [[CT scan]] suggestive of lung cancer include, a [[solitary pulmonary nodule]], centrally located masses, [[Mediastinal Mass|mediastinal invasion]]. A CT scan of the [[abdomen]] and [[brain]] can help visualize the common sites of [[metastases]]: [[adrenal glands]], [[liver]], and [[brain]]. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]].


===Laboratory Findings===
===Laboratory Findings===
The laboratory findings associated with lung cancer are the following: [[neutropenia]], [[hyponatremia]], [[hypokalemia]], [[hypercalcemia]], [[respiratory acidosis]], [[hypercarbia]], [[hypoxia]], and tumor cells in sputum and [[pleural effusion]] [[cytology]].
The [[Medical laboratory|laboratory]] findings associated with lung cancer are the following [[neutropenia]], [[hyponatremia]], [[hypokalemia]], [[hypercalcemia]], [[respiratory acidosis]], [[hypercarbia]], [[hypoxia]], and [[Tumor cell|tumor cells]] in [[sputum]] and [[pleural effusion]] [[cytology]].
===[[Electrocardiograpgy]]===
[[ECG]] is a simple [[method]] for finding evidence of [[pulmonary artery stenosis]] in [[metastatic]] [[lung cancer]] and should be routinely performed in such [[patients]]. Findings on [[ECG]] associated [[mediastinal]] [[metastatic]] of [[lung cancer]] led to [[pulmonary artery stenosis]] and [[right ventricular]] [[strain]] include [[right axis deviation]], deepened S wave in lead 1, sustantial R wave in lead avR, inverted/flattened T waves in [[limb]] and [[precordial]] [[leads]].
 
===X-ray===
Performing a [[chest x-ray]] is the first step if a [[patient]] reports [[Symptom|symptoms]] that may be suggestive of lung cancer. Lung cancers are usually detected on a routine [[Chest X-ray|chest x-ray]] in a person experiencing no [[Symptom|symptoms]].  


===X-Ray===
===Echocardiography and Ultrasound ===
Performing a [[chest x-ray]] is the first step if a patient reports symptoms that may be suggestive of lung cancer. Often lung cancers are picked up on a routine chest X-ray in a person experiencing no symptoms.
There are no [[echocardiography]]/[[ultrasound]] findings associated with lung cancer.


===CT===
===CT scan===
Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include, a solitary [[pulmonary nodule]], centrally located [[Tumor|masses]], [[Mediastinum|mediastinal]] invasion
[[Chest]] [[Computed tomography|CT scan]] is the modality of choice in the [[diagnosis]] of lung cancer. Findings on [[Computed tomography|CT scan]] suggestive of lung cancer include a [[Pulmonary nodule|solitary pulmonary nodule]], centrally located [[Tumor|masses]], [[Mediastinum|mediastinal]] [[Invasive (medical)|invasion]] [[Computed tomography|CT scans]] help [[Cancer staging|stage]] the lung cancer. A [[Computed tomography|CT scan]] of the [[abdomen]] and [[brain]] can help visualize the common sights of [[Metastasis|metastases]] such as [[Adrenal gland|adrenal glands]], [[liver]], and [[brain]]. [[Computed tomography|CT scans]] [[Diagnosis|diagnose]] lung cancer by providing [[anatomical]] detail to locate the [[tumor]], demonstrating proximity to the nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]].
CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases: adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the [[tumor]], demonstrating proximity to nearby structures, and deciphering whether [[lymph nodes]] are enlarged in the [[mediastinum]].


===MRI===
===MRI===
The indication of MRI in lung cancer is when there is a suspicion of spinal cord canal invasion, Pancoast tumors i.e superior [[sulcus]] tumors, and [[brachial plexus]] tumors.
The [[Indication (medicine)|indication]] of [[Magnetic resonance imaging|MRI]] in lung cancer is when there is a suspicion of [[spinal cord]] canal [[Invasive (medical)|invasion]] and/or in the presence of [[pancoast tumor]] ([[Sulcus (anatomy)|superior sulcus]] [[tumor]]) and [[brachial plexus]] [[Tumor|tumors]].


===Biopsy===
===Other Imaging Findings===
A transthoracic needle biopsy and a bronchoscopy are conducted to diagnose lung cancer.
There are no other [[imaging]] findings associated with lung cancer.


===Other Diagnostic Studies===
===Other Diagnostic Studies===
Other diagnostic studies include bone scintigraphy, [[PET scan]], and molecular tests.
Other [[Diagnosis|diagnostic]] studies include [[bone]] [[scintigraphy]], [[PET scan]], and [[molecular]] [[Test|tests]].


==Medical Therapy==
==Treatment==
The therapy for lung cancer consists of surgery, radiation therapy, chemotherapy, and targeted therapy.
===Medical Therapy===
[[Medical]] [[therapy]] for lung cancer consists of [[radiation therapy]], [[chemotherapy]], and targeted [[therapy]].


==Surgery==
===Surgery===
Lung cancer surgery involves the surgical excision of cancer tissue from the lung. It involves the surgical excision of cancer tissue from the lung. It is used mainly in non-small cell lung cancer with the intention of curing the patient.
Lung cancer [[surgery]] involves the [[Excision|surgical excision]] of the [[Cancer|cancerous]] [[Tissue (biology)|tissue]]. It is used mainly in [[non-small cell lung cancer]] with the intention of [[Cure|curing]] the [[patient]].


==Primary Prevention==
===Primary Prevention===
Effective measures for the primary prevention of lung cancer include smoking cessation and avoidance of second hand smoking. Lifestyle changes, such as healthy diet rich with fruits and vegetables and regular exercise, might decrease the risk of developing cancer in general.
Effective measures for the [[Prevention (medical)|primary prevention]] of lung cancer include [[smoking cessation]] and avoidance of [[Passive smoking|second hand smoking]]. Lifestyle changes, such as [[Health|healthy]] [[Diet (nutrition)|diet]] rich with [[Fruit|fruits]] and [[Vegetable|vegetables]] and regular [[Physical exercise|exercise]], might decrease the risk of developing cancer in general.


==Secondary Prevention==
===Secondary Prevention===
Secondary prevention for lung cancer consists of smoking cessation and screening. Secondary chemoprevention focuses on blocking the development of lung cancer in individuals in whom a precancerous lesion has been detected.
[[Prevention (medical)|Secondary prevention]] of lung cancer consists of [[smoking cessation]] and [[Screening (medicine)|screening]]. Secondary chemoprevention focuses on blocking the development of lung cancer in individuals in whom a [[precancerous]] [[lesion]] has been detected.


==References==
{{reflist|2}}
{{reflist|2}}



Latest revision as of 06:28, 28 July 2021

Lung cancer Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Lung cancer from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic study of choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

Echocardiography and Ultrasound

CT scan

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Dildar Hussain, MBBS [2];Kim-Son H. Nguyen M.D.;Saarah T. Alkhairy M.D;Cafer Zorkun, M.D., Ph.D. [3]

Overview

Prior to the introduction of cigarette smoking and industrial carcinogens, lung cancer was thought to be a rare disease. Of all the tumors detected on autopsy, lung cancer accounted for only 1% of cancers in the 1800s. The majority of cases of lung cancer were associated with occupational hazards due to radon exposure. The association between lung cancer and smoking was not defined until the mid-20th century. Primary lung cancers may be classified into small cell lung cancer (~15%) and non small cell lung cancer (~85%). Non small cell lung cancer are a heterogeneous group of lung cancers that are often grouped together because they share similar clinical features (e.g. prognosis and management). The 2015 WHO histological classification of tumors of the lung categorized lung tumors into malignant epithelial tumors, benign epithelial tumors, lymphoproliferative tumors, miscellaneous tumors, and metastatic tumors. The pathophysiology of lung cancer includes both genetic and environmental factors. Causality of the majority of lung cancer is linked to tobacco usage. Carcinogenic effects of tobacco smoking may result in DNA mis-replication and mutation. Smoking starts a cascade of events that leads to cancer development, even decades after smoking cessation. Besides smokers, patients with the history of prior respiratory tract or gastrointestinal tract cancer comprise a high-risk population. Other environmental factors include radon, asbestos, viral infections, and states of chronic lung inflammation, all of which may predispose to cellular damage and DNA mutations that predispose to the development of lung cancers. The direct cause of lung cancer is DNA mutations that often result in either activation of proto-oncogenes (e.g. K-RAS) or the inactivation of tumors suppressor genes (e.g. TP53) or both. The risk of these genetic mutations may be increased following exposure to environmental insults. Lung cancer must be differentiated from other conditions that cause hemoptysis, cough, dyspnea, wheezing, chest pain, dysphonia, dysphagia, unexplained weight loss, unexplained loss of appetite, and fatigue. These conditions include pneumonia, bronchitis, metastatic cancer from a non-thoracic primary site, infectious granuloma, pulmonary tuberculosis, tracheal tumors, and a thyroid mass. Lung cancer is the most common cause of cancer-associated mortality and the second most common type of cancer among both genders. Individuals > 50 years of age who have a history of smoking are at increased risk. Historically, the incidence of lung cancer is significantly higher among males compared to females. This increased ratio is thought to be attributed to the increased rates of smoking among men. However, more women are being diagnosed with lung cancer due to the increased rate of smoking among women. In 2014, the incidence of lung cancer in the United States was approximately 70 cases per 100,000. The most potent risk factor in the development of lung cancer is tobacco smoking. Other risk factors include second hand smoke, air pollution, family history of lung cancer, radiation therapy to the chest, and exposure to radon, asbestos and other chemical carcinogens. Lung cancer screening is a strategy used to identify early lung cancer in people, before they develop symptoms. Screening refers to the use of medical tests to detect disease in asymptomatic people. Screening studies for lung cancer have only been done in high risk populations, such as smokers and workers with occupational exposure to certain substances. This is because radiation exposure from screening could actually induce carcinogenesis in a small percentage of screened subjects, so this risk should be mitigated by a (relatively) high prevalence of lung cancer in the population being screened. A pulmonary nodule larger than 5 - 6 mm is considered a positive result for screening with x-ray or computed tomography. The majority of lung cancers present with advanced disease because the symptoms tend to occur later in the course of the disease. Patients experience non-specific symptoms such as cough, hemoptysis, dyspnea, chest pain, difficulty speaking, difficulty swallowing, lack of appetite, weight loss, and fatigue from 3 weeks to 3 months before seeking medical attention. There are a variety of complications associated with lung cancer, such as pleural effusion, leg weakness, paresthesias, bladder dysfunction, seizures, hemiplegia, cranial nerve palsies, confusion, personality changes, skeletal pain, pleuritic pain, atelectasis, and bronchopleural fistula. The prognosis of lung cancer is poor if diagnosed at the advanced stages. Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include a solitary pulmonary nodule, centrally located masses, mediastinal invasion CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases such as adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to the nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum. Common symptoms of lung cancer include difficulty breathing, hemoptysis, chronic coughing, chest pain, weakness and wasting, difficulty speaking, and symptoms related to paraneoplastic syndromes. Common physical examination findings of lung cancer include decreased/absent breath sounds, pallor, low-grade fever, and tachypnea. The laboratory findings associated with lung cancer are the following neutropenia, hyponatremia, hypokalemia, hypercalcemia, respiratory acidosis, hypercarbia, hypoxia, and tumor cells in sputum and pleural effusion cytology. Performing a chest x-ray is the first step if a patient reports symptoms that may be suggestive of lung cancer. Lung cancers are usually detected on a routine chest x-ray in a person experiencing no symptoms. There are no echocardiography/ultrasound findings associated with lung cancer. Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include a solitary pulmonary nodule, centrally located masses, mediastinal invasion CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases such as adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to the nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum. The indication of MRI in lung cancer is when there is a suspicion of spinal cord canal invasion and/or in the presence of pancoast tumor (superior sulcus tumor) and brachial plexus tumors. There are no other imaging findings associated with lung cancer. Other diagnostic studies include bone scintigraphy, PET scan, and molecular tests. Medical therapy for lung cancer consists of radiation therapy, chemotherapy, and targeted therapy. Lung cancer surgery involves the surgical excision of the cancerous tissue. It is used mainly in non-small cell lung cancer with the intention of curing the patient. Effective measures for the primary prevention of lung cancer include smoking cessation and avoidance of second hand smoking. Lifestyle changes, such as healthy diet rich with fruits and vegetables and regular exercise, might decrease the risk of developing cancer in general. Secondary prevention of lung cancer consists of smoking cessation and screening. Secondary chemoprevention focuses on blocking the development of lung cancer in individuals in whom a precancerous lesion has been detected.

Historical Perspective

Prior to the introduction of cigarette smoking and industrial carcinogens, lung cancer was thought to be a rare disease. Of all the tumors detected on autopsy, lung cancer accounted for only 1% of cancers in the 1800s. The majority of cases of lung cancer were associated with occupational hazards due to radon exposure. The association between lung cancer and smoking was not defined until the mid-20th century.

Classification

Primary lung cancers may be classified into small cell lung cancer (~15%) and non small cell lung cancer (~85%). Non small cell lung cancer are a heterogeneous group of lung cancers that are often grouped together because they share similar clinical features (e.g. prognosis and management). The 2015 WHO histological classification of tumors of the lung categorized lung tumors into malignant epithelial tumors, benign epithelial tumors, lymphoproliferative tumors, miscellaneous tumors, and metastatic tumors.

Pathophysiology

The pathophysiology of lung cancer includes both genetic and environmental factors. Causality of the majority of lung cancer is linked to tobacco usage. Carcinogenic effects of tobacco smoking may result in DNA mis-replication and mutation. Smoking starts a cascade of events that leads to cancer development, even decades after smoking cessation. Besides smokers, patients with the history of prior respiratory tract or gastrointestinal tract cancer comprise a high-risk population. Other environmental factors include radon, asbestos, viral infections, and states of chronic lung inflammation, all of which may predispose to cellular damage and DNA mutations that predispose to the development of lung cancers.

Causes

The direct cause of lung cancer is DNA mutations that often result in either activation of proto-oncogenes (e.g. K-RAS) or the inactivation of tumors suppressor genes (e.g. TP53) or both. The risk of these genetic mutations may be increased following exposure to environmental insults.

Differential Diagnosis

Lung cancer must be differentiated from other conditions that cause hemoptysis, cough, dyspnea, wheezing, chest pain, dysphonia, dysphagia, unexplained weight loss, unexplained loss of appetite, and fatigue. These conditions include pneumonia, bronchitis, metastatic cancer from a non-thoracic primary site, infectious granuloma, pulmonary tuberculosis, tracheal tumors, and a thyroid mass.

Epidemiology and Demographics

Lung cancer is the most common cause of cancer-associated mortality and the second most common type of cancer among both genders. Individuals > 50 years of age who have a history of smoking are at increased risk. Historically, the incidence of lung cancer is significantly higher among males compared to females. This increased ratio is thought to be attributed to the increased rates of smoking among men. However, more women are being diagnosed with lung cancer due to the increased rate of smoking among women. In 2014, the incidence of lung cancer in the United States was approximately 70 cases per 100,000.

Risk Factors

The most potent risk factor in the development of lung cancer is tobacco smoking. Other risk factors include second hand smoke, air pollution, family history of lung cancer, radiation therapy to the chest, and exposure to radon, asbestos and other chemical carcinogens.

Screening

Lung cancer screening is a strategy used to identify early lung cancer in people, before they develop symptoms. Screening refers to the use of medical tests to detect disease in asymptomatic people. Screening studies for lung cancer have only been done in high risk populations, such as smokers and workers with occupational exposure to certain substances. This is because radiation exposure from screening could actually induce carcinogenesis in a small percentage of screened subjects, so this risk should be mitigated by a (relatively) high prevalence of lung cancer in the population being screened. A pulmonary nodule larger than 5 - 6 mm is considered a positive result for screening with x-ray or computed tomography.

Natural History, Complications, and Prognosis

The majority of lung cancers present with advanced disease because the symptoms tend to occur later in the course of the disease. Patients experience non-specific symptoms such as cough, hemoptysis, dyspnea, chest pain, difficulty speaking, difficulty swallowing, lack of appetite, weight loss, and fatigue from 3 weeks to 3 months before seeking medical attention. There are a variety of complications associated with lung cancer, such as pleural effusion, leg weakness, paresthesias, bladder dysfunction, seizures, hemiplegia, cranial nerve palsies, confusion, personality changes, skeletal pain, pleuritic pain, atelectasis, and bronchopleural fistula. The prognosis of lung cancer is poor if diagnosed at the advanced stages.

Diagnosis

Diagnostic Study of Choice

Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include a solitary pulmonary nodule, centrally located masses, mediastinal invasion CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases such as adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to the nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum.

History and Symptoms

Common symptoms of lung cancer include difficulty breathing, hemoptysis, chronic coughing, chest pain, weakness and wasting, difficulty speaking, and symptoms related to paraneoplastic syndromes.

Physical Examination

Common physical examination findings of lung cancer include decreased/absent breath sounds, pallor, low-grade fever, and tachypnea.

Diagnostic Studies

Diagnostic study of choice

Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include, a solitary pulmonary nodule, centrally located masses, mediastinal invasion. A CT scan of the abdomen and brain can help visualize the common sites of metastases: adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum.

Laboratory Findings

The laboratory findings associated with lung cancer are the following neutropenia, hyponatremia, hypokalemia, hypercalcemia, respiratory acidosis, hypercarbia, hypoxia, and tumor cells in sputum and pleural effusion cytology.

Electrocardiograpgy

ECG is a simple method for finding evidence of pulmonary artery stenosis in metastatic lung cancer and should be routinely performed in such patients. Findings on ECG associated mediastinal metastatic of lung cancer led to pulmonary artery stenosis and right ventricular strain include right axis deviation, deepened S wave in lead 1, sustantial R wave in lead avR, inverted/flattened T waves in limb and precordial leads.

X-ray

Performing a chest x-ray is the first step if a patient reports symptoms that may be suggestive of lung cancer. Lung cancers are usually detected on a routine chest x-ray in a person experiencing no symptoms.

Echocardiography and Ultrasound

There are no echocardiography/ultrasound findings associated with lung cancer.

CT scan

Chest CT scan is the modality of choice in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include a solitary pulmonary nodule, centrally located masses, mediastinal invasion CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases such as adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to the nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum.

MRI

The indication of MRI in lung cancer is when there is a suspicion of spinal cord canal invasion and/or in the presence of pancoast tumor (superior sulcus tumor) and brachial plexus tumors.

Other Imaging Findings

There are no other imaging findings associated with lung cancer.

Other Diagnostic Studies

Other diagnostic studies include bone scintigraphy, PET scan, and molecular tests.

Treatment

Medical Therapy

Medical therapy for lung cancer consists of radiation therapy, chemotherapy, and targeted therapy.

Surgery

Lung cancer surgery involves the surgical excision of the cancerous tissue. It is used mainly in non-small cell lung cancer with the intention of curing the patient.

Primary Prevention

Effective measures for the primary prevention of lung cancer include smoking cessation and avoidance of second hand smoking. Lifestyle changes, such as healthy diet rich with fruits and vegetables and regular exercise, might decrease the risk of developing cancer in general.

Secondary Prevention

Secondary prevention of lung cancer consists of smoking cessation and screening. Secondary chemoprevention focuses on blocking the development of lung cancer in individuals in whom a precancerous lesion has been detected.

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