By Catlin Nalley
Given BRCA mutations are linked to a higher lifetime risk of ovarian and breast cancers, many women with these gene mutations often consider preventive measures, including mastectomy or removal of the ovaries and fallopian tubes.
New research, however, suggests that for women with BRCA mutations who have already had ovarian cancer, the benefits of risk-reducing mastectomies may not outweigh the costs.
Researchers from the Duke Cancer Institute found that for many women in this patient population, prophylactic mastectomy does not produce a substantial survival gain and is not cost-effective (Ann Surg Oncol 2017; doi:10.1245/s10434-017-5995-z).
This study was prompted, in part, by the recent changes in NCCN guidelines that recommended that women with ovarian cancer undergo BRCA mutation testing, regardless of family history, noted senior author Rachel Greenup, MD, MPH, Assistant Professor of Surgery at Duke. With this shift in guidelines, more women will learn of their BRCA-mutation and increased risk of breast cancer following ovarian cancer diagnosis.
"Risk-reducing mastectomy is costly and can require many months of follow-up and recovery," Charlotte Gamble, MD, the study's lead author and a resident physician at Duke University School of Medicine said, in a statement. "Our results emphasize that prophylactic mastectomy should be used selectively in women with both a BRCA mutation and a history of ovarian cancer."
Study Methodology, Results
Researchers constructed a statistical model comparing risk-reducing mastectomy to surveillance that included mammogram and MRI, according to Greenup.
"The model incorporated factors like age at ovarian cancer diagnosis, time to risk-reducing mastectomy, BRCA mutation status, survival rates, and treatment costs," she explained. "Risk-reducing mastectomy was compared to breast cancer screening every 6 months from 1-15 years after ovarian cancer diagnosis."
Data were also separated into four categories based on the age at time of the initial ovarian cancer diagnosis: younger than 40, 40-50, 50-60, and 60-70.
The incremental cost-effectiveness ration, a cost-effectiveness measure, was also considered by study authors. "Health care interventions where this ratio is less than $100,000 per year of life saved are commonly considered cost-effective in medical literature," according to researchers. This threshold was utilized in the study.
The benefits of risk-reducing mastectomy compared to screening alone depended on the age of the patient at the time of their ovarian cancer diagnosis and time to mastectomy, according to investigators.
"[We] found that, within the first 4 years after ovarian cancer diagnosis, prophylactic mastectomy was associated with a negligible gain in months of survival," reported Greenup. "It was, therefore, not found to be cost-effective among women of any age with BRCA 1 and 2 gene mutations."
For women diagnosed at age 60 or older, the gain in survival months was also negligible and procedure would not be cost-effective, regardless of time since ovarian cancer diagnosis.
Among women ages 40-50 with BRCA 1 and 2 mutations, the procedure was associated with a survival benefit of 2-5 months compared to screening, Greenup told Oncology Times. "This was found to be cost-effective when performed at least 5 years after an ovarian cancer diagnosis," she explained.
One limitation of the study, noted Greenup, is the model's dependency on previously published incidence rates and costs, which may not entirely reflect current numbers.
This study offers guidance to women and physicians who are debating the benefits and timing of prophylactic mastectomy following ovarian cancer treatment.
"Our study provides clarity on how a woman's age and timing of a risk-reducing mastectomy after an ovarian cancer diagnosis impact the benefit of this procedure," Gamble said. "Within the first 5 years, nobody benefitted from risk-reducing mastectomy and, after that threshold, survival gains were seen mostly in the youngest, healthiest ovarian cancer patients."
"There is no right or wrong answer on how to manage breast cancer risk in this unique population," added Greenup. "However, we hope that our findings provide guidance to women and their doctors deciding if and when prophylactic mastectomy is beneficial following ovarian cancer treatment.
"Certainly, this unique subset of women can focus on the treatment of their ovarian cancer and be reassured that prophylactic mastectomy provides minimal benefit in the immediate period after ovarian cancer diagnosis," she concluded.
Catlin Nalley is associate editor.