Colorectal cancer screening: Difference between revisions
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Offering choice of colonoscopy or iFOBT might increase compliance.<ref name="pmid22493463">{{cite journal| author=Inadomi JM, Vijan S, Janz NK, Fagerlin A, Thomas JP, Lin YV et al.| title=Adherence to colorectal cancer screening: a randomized clinical trial of competing strategies. | journal=Arch Intern Med | year= 2012 | volume= 172 | issue= 7 | pages= 575-82 | pmid=22493463 | doi=10.1001/archinternmed.2012.332 | pmc=PMC3360917 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22493463 }} </ref> | |||
A more recent [[randomized controlled trial]] in 2012 by the COLONPREV group updates the USPSTF findings and states, screening with FIT was very similar to one-time colonoscopy with respect to the rate of detection of colorectal cancer.”<ref name="pmid22356323">{{cite journal| author=Quintero E, Castells A, Bujanda L, Cubiella J, Salas D, Lanas Á et al.| title=Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. | journal=N Engl J Med | year= 2012 | volume= 366 | issue= 8 | pages= 697-706 | pmid=22356323 | doi=10.1056/NEJMoa1108895 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22356323 }} </ref> | A more recent [[randomized controlled trial]] in 2012 by the COLONPREV group updates the USPSTF findings and states, screening with FIT was very similar to one-time colonoscopy with respect to the rate of detection of colorectal cancer.”<ref name="pmid22356323">{{cite journal| author=Quintero E, Castells A, Bujanda L, Cubiella J, Salas D, Lanas Á et al.| title=Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. | journal=N Engl J Med | year= 2012 | volume= 366 | issue= 8 | pages= 697-706 | pmid=22356323 | doi=10.1056/NEJMoa1108895 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22356323 }} </ref> | ||
Analyses vary in their estimates of benefit. | Analyses vary in their estimates of benefit. | ||
Revision as of 16:25, 16 April 2015
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Elliot B. Tapper, M.D., Beth Israel Deaconess Medical Center; Michael Maddaleni, B.S.
Overview
Current guidelines suggest that a colonoscopy is the best screening tool for colon cancer; in fact, colonoscopy detects colon cancer in 98-99% of the cases.[1] A colonoscopy every 10 years reduces the risk of left sided colon cancer but not as much for right sided colon cancer. Right sided colon cancers are more likely to be missed because they are harder to reach and they could be flat, which means they would be harder to detect. Flat growths (non-polypoid) are difficult to detect and are more likely to progress to colon cancer compared to cylindrical polyps.[1] Spray on dyes may better help to detect flat growths.
Screening
Colorectal cancer can take many years to develop and early detection of colorectal cancer greatly improves the chances of a cure.
Clinical practice guidelines
Clinical practice guidelines by the United States Preventive Service Task Force (USPSTF)in 2008 stated:[2]
- "The USPSTF recommends screening for colorectal cancer using fecal occult blood testing, sigmoidoscopy, or colonoscopy in adults, beginning at age 50 years and continuing until age 75 years." (Grade A)
- "The USPSTF recommends against routine screening for colorectal cancer in adults 76 to 85 years of age. There may be considerations that support colorectal cancer screening in an individual patient." (Grade C)
- "The USPSTF recommends against screening for colorectal cancer in adults older than age 85 years." (Grade D)
The USPSTF concludes that the evidence is insufficient to assess the benefits and harms of computed tomographic colonography and fecal DNA testing as screening modalities for colorectal cancer. (Grade I)
The American College of Gastroenterology recommends:[3]
- Screening in African Americans should begin at age 45 years.
- CT colonography every 5 years is the radiographic screening alternative, when patients decline colonoscopy.
- Fecal immunochemical test for blood (FIT) is preferred over guaiac-based fecal occult blood testing.
Evidence
Offering choice of colonoscopy or iFOBT might increase compliance.[4]
A more recent randomized controlled trial in 2012 by the COLONPREV group updates the USPSTF findings and states, screening with FIT was very similar to one-time colonoscopy with respect to the rate of detection of colorectal cancer.”[5] Analyses vary in their estimates of benefit.
A network meta-analysis found that colonoscopy is the best test. This analysis found that compared with no intervention, relative risk (RR) and number needed to treat (NNT) for reducing mortality from colorectal cancer[6]:
- gFOBT: RR 0.82 (95% CI, 0.76-0.88) and NNT 556
- Flexible sigmoidoscopy: RR 0.60 (95% CI, 0.45-0.78), and NNT 250
- Colonoscopy: RR 0.43 (95% CI, 0.33-0.58) and NNT 175
Additional projections of screening for detecting cancer:
- Number needed to screen for colonoscopy is 191[5]
- Number needed to screen for iFOBT is 281[5]
- Number needed to screen for gFOBT is 1173[7]
Fecal Occult Blood Testing
Fecal occult blood test (FOBT): a test for blood in the stool. Two types of tests can be used for detecting occult blood in stools i.e. guaiac based (chemical test) and immunochemical. A meta-analysis found that the number needed to screen (mortality) for sigmoidoscopy is 850.[8]
Endoscopy
Sigmoidoscopy: A lighted probe (sigmoidoscope) is inserted into the rectum and lower colon to check for polyps and other abnormalities. A meta-analysis found that the number needed to screen (mortality) for sigmoidoscopy is 850.[8]
Colonoscopy: A lighted probe called a colonoscope is inserted into the rectum and the entire colon to look for polyps and other abnormalities that may be caused by cancer. A colonoscopy has the advantage that if polyps are found during the procedure they can be immediately removed. Tissue can also be taken for biopsy. The American Society for Gastrointestinal Endoscopy has released quality indicators for screening colonoscopy, which include:[9]
- Documentation of prep quality
- Photo documentation of cecal intubation
- Withdrawal time of 6 minutes or more
- Adenoma detection rate of greater than 25% in males and 15% in females greater than 50 years old.
Other Screening Techniques
- Double contrast barium enema (DCBE): First, an overnight preparation is taken to cleanse the colon. An enema containing barium sulfate is administered, then air is insufflated into the colon, distending it. The result is a thin layer of barium over the inner lining of the colon which is visible on X-ray films. A cancer or a precancerous polyp can be detected this way. This technique can miss the (less common) flat polyp.
- Virtual colonoscopy replaces X-ray films in the double contrast barium enema (above) with a special computed tomography scan and requires special workstation software in order for the radiologist to interpret. This technique is approaching colonoscopy in sensitivity for polyps. However, any polyps found must still be removed by standard colonoscopy.
- Blood tests: Measurement of the patient's blood for elevated levels of certain proteins can give an indication of tumor load. In particular, high levels of carcinoembryonic antigen (CEA) in the blood can indicate metastasis of adenocarcinoma. These tests are frequently false positive or false negative, and are not recommended for screening, it can be useful to assess disease recurrence.
- Stool DNA testing detects DNA shed into the stool from the cells of pre-malignant adenomas and cancers. The DNA is not degraded during the digestive process and remain stable in the stool. Capture, followed by Polymerase Chain Reaction amplifies the DNA to detectable levels for assay. Clinical studies have shown a cancer detection sensitivity of 71%-91%[10], and may be more sensitive than fecal immunochemical testing.[11]
Genetic Testing
- Genetic counseling and genetic testing is a screening modality for families who may have a hereditary form of colon cancer, such as hereditary nonpolyposis colorectal cancer (HNPCC) or familial adenomatous polyposis (FAP).
References
- ↑ 1.0 1.1 American Society of Clinical Oncology. 2010. Progress in Cancer Screening. http://owl.english.purdue.edu/owl/resource/560/10/
- ↑ U.S. Preventive Services Task Force (2008). "Screening for colorectal cancer: U.S. Preventive Services Task Force recommendation statement". Ann Intern Med. 149 (9): 627–37. PMID 18838716.
- ↑ Rex DK, Johnson DA, Anderson JC, et al. American College of Gastroenterology guidelines for colorectal cancer screening 2009.Am J Gastroenterol. 2009 Mar;104(3):739-50.
- ↑ Inadomi JM, Vijan S, Janz NK, Fagerlin A, Thomas JP, Lin YV; et al. (2012). "Adherence to colorectal cancer screening: a randomized clinical trial of competing strategies". Arch Intern Med. 172 (7): 575–82. doi:10.1001/archinternmed.2012.332. PMC 3360917. PMID 22493463.
- ↑ 5.0 5.1 5.2 Quintero E, Castells A, Bujanda L, Cubiella J, Salas D, Lanas Á; et al. (2012). "Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening". N Engl J Med. 366 (8): 697–706. doi:10.1056/NEJMoa1108895. PMID 22356323.
- ↑ Elmunzer BJ, Singal AG, Sussman JB, Deshpande AR, Sussman DA, Conte ML; et al. (2015). "Comparing the effectiveness of competing tests for reducing colorectal cancer mortality: a network meta-analysis". Gastrointest Endosc. 81 (3): 700–709.e3. doi:10.1016/j.gie.2014.10.033. PMID 25708757.
- ↑ Hewitson P, Glasziou P, Irwig L, Towler B, Watson E (2007). "Screening for colorectal cancer using the faecal occult blood test, Hemoccult". Cochrane Database Syst Rev (1): CD001216. doi:10.1002/14651858.CD001216.pub2. PMID 17253456. Review in: Evid Based Nurs. 2007 Oct;10(4):112
- ↑ 8.0 8.1 Elmunzer BJ, Hayward RA, Schoenfeld PS, Saini SD, Deshpande A, Waljee AK (2012). "Effect of flexible sigmoidoscopy-based screening on incidence and mortality of colorectal cancer: a systematic review and meta-analysis of randomized controlled trials". PLoS Med. 9 (12): e1001352. doi:10.1371/journal.pmed.1001352. PMC 3514315. PMID 23226108.
- ↑ Rex DK, Petrini JL, Baron TH, Chak A, Cohen J, Deal SE; et al. (2006). "Quality indicators for colonoscopy". Am J Gastroenterol. 101 (4): 873–85. doi:10.1111/j.1572-0241.2006.00673.x. PMID 16635231.
- ↑ B. Greenwald (2006). "The DNA Stool Test - An Emerging Technology in Colorectal Cancer Screening".
- ↑ Imperiale TF, Ransohoff DF, Itzkowitz SH, Levin TR, Lavin P, Lidgard GP; et al. (2014). "Multitarget stool DNA testing for colorectal-cancer screening". N Engl J Med. 370 (14): 1287–97. doi:10.1056/NEJMoa1311194. PMID 24645800.