Metastatic breast cancer treatment

Revision as of 20:19, 1 December 2011 by Jack Khouri (talk | contribs)
Jump to navigation Jump to search

Breast Cancer Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Breast 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

CT scan

MRI

Echocardiography or Ultrasound

Other Imaging Studies

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Metastatic breast cancer treatment On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Metastatic breast cancer treatment

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Metastatic breast cancer treatment

CDC on Metastatic breast cancer treatment

Metastatic breast cancer treatment in the news

Blogs on Metastatic breast cancer treatment

Directions to Hospitals Treating Breast cancer

Risk calculators and risk factors for Metastatic breast cancer treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Assistant Editor-in-Chief Jack Khouri

Overview

With rare exception, metastatic breast cancer is an incurable but treatable illness. Currently, it is managed as a chronic disease, especially the category that is ER-positive with predominantly bone or soft tissue metastasis. Chemotherapy, biologic therapy and endocrine therapy are all considered in the treatment of metastatic breast cancer.

Principles of therapy

  • The main aims of therapy are prolonging survival, improving quality of life and avoiding treatment-induced toxicity. Given that treatment is palliative, patients should be given treatment holidays in order to reduce drug-induced toxicity.
  • HER2 overexpression and hormone receptor status are very important factors that guide therapy and influence prognosis.
  • Multiagent chemotherapy regimens don't show significant survival benefit compared to single-drug regimens and augment toxicity.
  • Chemotherapy is recommended for patients with ER-negative metastatic breast cancer and those with ER-positive breast cancer resistant to endocrine therapy or associated with visceral disease.
  • Trastuzumab increases the clinical benefit of first-line chemotherapy in metastatic breast cancer that overexpresses HER2.[1]
  • Single-agent trastuzumab is active and well tolerated as first-line treatment of women with metastatic breast cancer with HER2 overexpression.[2]

Chemotherapy

  • the most active single agents are Anthracyclines (Doxorubicin 60-75 mg/m2 IV every 21 days), Taxanes (paclitaxel 175 mg/m2 every 21 days or 80 mg/m2 IV days 1,8,15 every 21 days; docetaxel 60-100 mg/m2 IV every 21 days), Capecitabine (1000-1250 mg/m2 PO twice a day on days 1-14 every 21 days), Gemcitabine (800-1200 mg/m2 IV days 1,8,15 every 28 days), and Vinorelbine (25 mg/m2 weekly or days 1,8,15 every 28 days)
  • Bevacizumab has been shown to improve the efficacy of taxanes in frontline treatment of patients with metastatic breast cancer.[3]
  • Combination chemotherapy include Gemcitabine combined with paclitaxel and docetaxel ombined with capecitabine.
  • There is little evidence from trials reported from 2000 to 2007 that major survival differences exist between many commonly employed chemotherapy regimens.[4]
  • Trastuzumab should be added to chemotherapy. If progression of disease occurs, Lapatinib and capecitabine are recommended concomitantly.

Endocrine Therapy

  • Endocrine therapy is based on the fact that estrogen receptor-positive tumors are highly estrogen-dependent for growth.
  • Endocrine therapy agents for breast cancer are meant to block the effect the estrogen growth effect on breast cancer cells via several mechanisms:
    • Blocking the estrogen receptor (eg, Selective Estrogen Receptor Modulators like Tamoxifen)
    • Down-regulating and degrading the estrogen receptor (eg, Fulvestrant which is a pure estrogen antagonist)[5]
    • Decreasing estrogen synthesis by blocking the enzyme called Aromatase, which converts androgens to estrogens. Aromatase inhibitors include many agents like Anastrozole, Letrozole and Exemestane
    • Decreasing estrogen level by:
      • Shutting down the hypothalamus-pituitary-ovarian axis by means of GnRH agonists, which block the hypothalamic signal that normally promotes etrogen synthesis by the ovaries
      • Ablating the ovaries (oophorectomy)
  • Endocrine therapy should be the first-line treatment for ER-positive metastatic breast cancer unless there is significant visceral involovement (the so-called visceral crisis (ie, liver or lung disease)) where first-line chemotherapy should be offered first.
  • There is no survival advantage for the combined administration of chemotherapy and endocrine therapy over either single therapy.[6] [7]

The factors that need to be taken into account when considering what endocrine therapy is appropriate for a particular patient include:[8]

  • Whether or not they have had previous endocrine therapy (including as an adjuvant)
  • If so, which agent
  • The extent and duration of any previous response to endocrine therapy
  • Menopausal status

Tamoxifen

  • Tamoxifen (TAM) is a SERM meaning that its effect on estrogen receptors depends on the target tissue. In fact, TAM inhibits breast cancer growth by competitive blockade of the estrogen receptor in breast tissue. The net result is a block in the G1 phase of the cell cycle and a slowing of cell proliferation. Tumors may then regress because of this altered balance between cell proliferation and ongoing cell loss. However, it has agonistic activiy in other tissues such as bone and uterus and blood vessels which is responsible for the side effects observed in patients on TAM, such as VTE and uterine cancer.
  • TAM is the first-line recommended endocrine agent for premenopausal metastatic breast cancer patients and the second-line agent for postmenopausal patients relapsing on/after aromatase inhbitors.
  • Small, randomized trials in premenopausal women have found that oophorectomy is not superior to TAM.[9]
  • Tamoxifen is a first-line treatment to men with ER-positive advanced breast cancer.[8]
  • An oral dose of 20 mg daily is the standard of care.

Aromatase Inhibitors

Aromatase Inhibitors (AIs) are drugs that suppress the enzyme aromatase present in many tissue such as the gonads, the adipose tissue, the placenta, and the endometrium. By blocking this enzyme, estrogen synthesis is suppressed and thus the trophic effects of estrogen on the breast tissue are rendered minimal. Aromatase inhibitor therapy is ONLY effective in suppressing estrogen levels in postmenopausal women.[8] Because of that, measurement of serum follicle-stimulating hormone (FSH) levels can help selecting the proper patient population.

  • In a randomized, double-blind, multicenter study designed to evaluate anastrozole (an AI), it was found that there was a significant increase in time to progression and a lower incidence of thromboembolic events and vaginal bleeding with anastrozole. These findings indicate that anastrozole should be considered as first-line therapy for postmenopausal women with advanced breast cancer.[10]

Offer an AI to: [8]

  • postmenopausal women with ER-positive breast cancer and no prior history of endocrine therapy
  • postmenopausal women with ER-positive breast cancer previously treated with tamoxifen

All aromatase inhibitors appear to be equally effective in terms of primary outcome (overall survival).

The most commonly used AIs are the following:

  • Letrozole (Femara): 2.5 mg PO daily
  • Anastrozole (Arimidex): 1 mg PO daily
  • Exemestane (Aromasin) 25 mg PO daily

Ovarian suppression with GnRH agonists

Ovarian suppression is indicated for premenopausal and perimenopausal women who have previously been treated with tamoxifen and then experience disease progression.[8] The combination of a GnRH agonist and tamoxifen is superior to GnRH agonist alone in premenopausal women with advanced breast cancer. Therefore, if a premenopausal woman with advanced breast cancer is thought to be suitable for endocrine treatment, the combination of a GnRH agonist plus tamoxifen be considered as the new standard treatment.[11] .

References

  1. Slamon DJ, Leyland-Jones B, Shak S, Fuchs H, Paton V, Bajamonde A et al. (2001) Use of chemotherapy plus a monoclonal antibody against HER2 for metastatic breast cancer that overexpresses HER2. N Engl J Med 344 (11):783-92. DOI:10.1056/NEJM200103153441101 PMID: 11248153
  2. Vogel CL, Cobleigh MA, Tripathy D, Gutheil JC, Harris LN, Fehrenbacher L et al. (2002) Efficacy and safety of trastuzumab as a single agent in first-line treatment of HER2-overexpressing metastatic breast cancer. J Clin Oncol 20 (3):719-26. PMID: 11821453
  3. Alvarez RH, Guarneri V, Icli F, Johnston S, Khayat D, Loibl S et al. (2011) Bevacizumab Treatment for Advanced Breast Cancer. Oncologist ():. DOI:10.1634/theoncologist.2011-0113 PMID: 21976315
  4. Wilcken N, Dear R (2008) Chemotherapy in metastatic breast cancer: A summary of all randomised trials reported 2000-2007. Eur J Cancer 44 (15):2218-25. DOI:10.1016/j.ejca.2008.07.019 PMID: 18722111
  5. Kansra S, Yamagata S, Sneade L, Foster L, Ben-Jonathan N (2005) Differential effects of estrogen receptor antagonists on pituitary lactotroph proliferation and prolactin release. Mol Cell Endocrinol 239 (1-2):27-36. DOI:10.1016/j.mce.2005.04.008 PMID: 15950373
  6. Stockler M, Wilcken NR, Ghersi D, Simes RJ (2000) Systematic reviews of chemotherapy and endocrine therapy in metastatic breast cancer. Cancer Treat Rev 26 (3):151-68. DOI:10.1053/ctrv.1999.0161 PMID: 10814559
  7. Fossati R, Confalonieri C, Torri V, Ghislandi E, Penna A, Pistotti V et al. (1998) Cytotoxic and hormonal treatment for metastatic breast cancer: a systematic review of published randomized trials involving 31,510 women. J Clin Oncol 16 (10):3439-60. PMID: 9779724
  8. 8.0 8.1 8.2 8.3 8.4 [[]]. PMID 21901868. Missing or empty |title= (help); |access-date= requires |url= (help)
  9. Buchanan RB, Blamey RW, Durrant KR, Howell A, Paterson AG, Preece PE et al. (1986) A randomized comparison of tamoxifen with surgical oophorectomy in premenopausal patients with advanced breast cancer. J Clin Oncol 4 (9):1326-30. PMID: 3528402
  10. Nabholtz JM, Buzdar A, Pollak M, Harwin W, Burton G, Mangalik A et al. (2000) Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group. J Clin Oncol 18 (22):3758-67. PMID: 11078488
  11. Klijn JG, Blamey RW, Boccardo F, Tominaga T, Duchateau L, Sylvester R et al. (2001) Combined tamoxifen and luteinizing hormone-releasing hormone (LHRH) agonist versus LHRH agonist alone in premenopausal advanced breast cancer: a meta-analysis of four randomized trials. J Clin Oncol 19 (2):343-53. PMID: 11208825

Template:WH Template:WS