More women opt for preventive mastectomy after Rx

An increasing number of women diagnosed with breast cancer chose to undergo contralateral prophylactic mastectomy, but this option only showed a real survival benefit in women who met certain criteria in terms of age, disease stage, and disease status.

Isabelle Bedrosian, MD, and colleagues in the department of surgical oncology at Houston's M. D. Anderson Cancer Center conducted a retrospective, population-based study using the SEER registry. They identified 107,106 breast cancer patients who underwent a mastectomy for treatment and a subset of 8,902 women who had contralateral prophylactic mastectomy (CPM).

All of the women were treated for early-stage (I-III breast cancer between 1998 and 2003. Patients were stratified for ER status, stage of disease, and age. Breast cancer-specific survival served as the study's primary endpoint (J Natl Cancer Inst 102:401-409, 2010).

They found a clear survival benefit for less than 10% of the breast cancer population, specifically those women who were younger than age 50 with stage I or II cancer with ER-negative disease. These women saw a survival benefit of 4.8% at five years.

Dr. Bedrosian pointed out that while their findings could serve as a guideline for breast cancer patients and their physicians for a discussion about CPM, the results do not determine that CPM is medically inappropriate for women who do not meet the criteria above.

"Our research found that breast cancer patients over the age of 60 can be reassured that they will not benefit from CPM," she said. "However, there are other populations, such as women between the age of 50 and 60, where the findings about the procedure remain less clear."

In previous research, Doreen M. Agnese, MD, and colleagues at Ohio State University Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute in Columbus identified 1,639 women with breast cancer who selected unilateral mastectomy, and 201 women who selected contralateral prophylactic mastectomy to treat unilateral breast cancer, at their institution between 1998 and 2007. They noted an increasing trend in the removal of both breasts: 16.1% of women chose mastectomy in 2007 compared with 6.5% in 1999 (Ann Surg Oncol 16:2691-2696, 2009).

"Our experience parallels the national trend of the increasing use of contralateral prophylactic mastectomy in women diagnosed with unilateral breast cancer," Dr. Agnese said. "Women who chose to have this preventive procedure were younger, more highly educated, and more likely to have a family history of cancer." Research has shown that removing a healthy breast is unlikely to affect survival because tumors in the second breast tend to be detected at an earlier stage than those in the first breast, she added.