The take-home message from the POSH trial is that by using treatment that is still standard of care, [patients with] BRCA-positive breast cancer have outcomes that are not worse than BRCA-negative patients.

— Leif Ellisen, MD, PhD

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Results of this trial have been anticipated for a long time. Women were enrolled between 2000 and 2008,” said Leif Ellisen, MD, PhD, Program Director of Breast Medical Oncology at Massachusetts General Hospital Cancer Center in Boston.

Regarding the survival advantage in triple-negative BRCA-positive breast cancer, Dr. Ellisen was not surprised. “We know that the outcome is better in BRCA-positive ovarian cancer with platinum-based chemotherapy because these women are platinum-sensitive. In the Prospective Study of Outcomes in Sporadic and Hereditary [POSH] trial, women with breast cancer were treated with standard-of-care treatment that did not include platinum, but there has been a sense that BRCA-positive breast cancers are chemosensitive.”

Take-Home Message

“The take-home message from the POSH trial is that by using breast cancer treatment that is still standard of care, patients with BRCA-positive breast cancer have outcomes that are not worse than BRCA-negative patients. BRCA-positive patients do not have to worry that their outcomes will be worse than BRCA-negative patients on standard chemotherapy when matched for stage and subtype,” he emphasized.

“Bilateral mastectomy is an increasing trend now among BRCA carriers. Studies show > 90% decrease in new breast cancers, but there is no practice-changing study showing a breast cancer–specific survival benefit or an overall survival benefit for bilateral mastectomy . The National Comprehensive Cancer Network^® (NCCN^®) guidelines are to discuss bilateral mastectomy with patients as an option to reduce the chances of developing breast cancer, and patients are informed that if they chose to preserve their breasts, there is a risk of additional breast cancers,” he said.

“This study did not address screening. Many young women who are known BRCA carriers are managed by oncologists. It is important that these women receive appropriate screening, as well as counseling regarding the pros and cons of risk-reducing mastectomy before they develop cancer” Dr. Ellisen said. ■

Disclosure: Dr. Ellisen reported no potential conflicts of interest.