Bilateral Prophylactic Mastectomy ‘No Added Benefit’ for Breast Cancer Survival

Breast conserving surgery with radiotherapy is as effective as bilateral prophylactic mastectomy for the treatment of unilateral breast cancer

medwireNews: Bilateral prophylactic mastectomy does not improve breast cancer patient survival compared with lumpectomy with radiotherapy, suggests research published in JAMA.

The 10-year mortality rate for breast conserving surgery plus radiotherapy was 16.8% and did not significantly differ from that of bilateral mastectomy at 18.8%, report Scarlett Gomez, from the Cancer Prevention Institute of California in Fremont, USA, and co-authors.

However, data from the California Cancer Registry indicate that patients who undergo unilateral mastectomy have significantly lower survival than those who undergo bilateral mastectomy or breast conserving procedures, with a 10-year mortality rate of 20.1% and a hazard ratio for all-cause mortality of 1.35.

Overall mortality was also associated with older age, tumour size and grade, nodal involvement, hormone Receptor status, being single and socioeconomic status, including being treated at a hospital predominantly treating low socioeconomic status patients.

“In a time of increasing concern about overtreatment, the risk-benefit ratio of bilateral mastectomy warrants careful consideration and raises the larger question of how physicians and society should respond to a patient’s preference for a morbid, costly intervention of dubious effectiveness”, the researchers caution.

Nevertheless, they note that family history, genetic predisposition and patient fear of a second cancer and other concerns may influence treatment choices.

Commenting in a press release, author Scarlett Gomez said: "We're hopeful that this study will open a dialogue between a patient and her physician to discuss these kinds of question. It's an important piece of evidence that can guide their decision-making process.”

The study included 189,734 patients with stage 0 to III breast cancer who were followed up for a median of 89.1 months between 1998 and 2011.

Over this period, bilateral mastectomy became increasingly common, rising to 12.3% of all patients and 33.0% of those aged less than 40 years. Bilateral mastectomy was associated with non-Hispanic White ethnicity, private health insurance and care at a National Cancer Institute-designated centre.

By contrast, unilateral mastectomy patients were less likely to be non-Hispanic White, to have public or Medicaid insurance and be treated in hospitals predominantly caring for patients with low socioeconomic status.

The researchers suggest that unilateral mastectomy choice may also be associated with subtle disparities in treatment access, such as diabetic neuropathy reducing chemotherapy or lack of transport for repeat hospital visits for radiotherapy.

“By contrast, patterns of bilateral mastectomy use suggest that affluent non-Hispanic white women, women of high [socioeconomic status], or both seek more aggressive preventive care, consistent with reported associations between greater use of expensive diagnostic tests (such as breast [magnetic resonance imaging] and genetic testing) and bilateral mastectomy within this patient subgroup”, they add.

Reference

Kurian A, Lichtensztajn D, Keegan T, et al. Use of and mortality after bilateral mastectomy compared with other surgical treatments for breast cancer in California, 1998–2011. JAMA 2014; 312(9):902-914. doi:10.1001/jama.2014.10707

medwireNews (www.medwireNews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014