Study urges genetic testing before abdominal-based free-flap breast reconstruction

For women with breast cancer who opt for breast reconstruction using a tissue flap from the abdomen, gene testing for high-risk mutations should be performed before surgery, concludes a report in the July issue of Plastic and Reconstructive Surgery^®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

Although only a small percentage of patients will test positive for BRCA or other high-risk mutations, genetic testing should be considered for all women in whom unilateral (single) mastectomy and abdominal-based free-flap breast reconstruction (FFBR) is planned, according to the study by Erez Dayan, MD, of Brigham & Women's Hospital/Harvard Medical School and colleagues.

Genetic testing before FFBR lowers costs, avoids repeated surgery

The study included 160 women with breast cancer who underwent single (unilateral) mastectomy followed by abdominal-based tissue breast reconstruction between 2007 and 2016. This approach to breast reconstruction uses a flap of tissue from the patient's abdomen. Some women choose this autologous reconstruction approach, rather than implant-based breast reconstruction.

Based on a personal or family history of breast cancer, 111 women met guidelines for genetic testing before mastectomy and breast reconstruction. For women with BRCA mutations, breast cancer risk is approximately five times higher than in women without a mutation. Some of these high-risk women will undergo "preventive" mastectomy to reduce their risk of breast cancer.

In the study, only about 56 percent of of patients who met criteria for genetic testing were actually tested. Testing was also performed in 10 percent of women who did not meet criteria.

At an average follow-up of about six years, three patients developed cancer of the opposite breast. All three of these women proved to have a high-risk mutation that could have been detected by genetic testing before surgery.

Thus in the total experience of 160 patients, 1.9 percent were diagnosed with harmful mutations after reconstruction, which led to a second mastectomy and reconstruction. "These subsequent cancers resulted in additional surgeries after the patients had completed multi-staged reconstructions, carrying psychosocial and financial burdens for patients and increased costs for the healthcare system," Dr. Dayan comments.

If the women had known they were at high risk, they might have chosen to undergo risk-reducing mastectomy and reconstruction. That's especially important before abdominal-based tissue breast reconstruction, because the abdominal donor site can only be used once.

The researchers also looked at the cost-effectiveness of expanding genetic testing for breast cancer. While testing all patients would have increased costs, it would have avoided the additional costs of treating the second cancers, reducing total costs by about $260,000. Dr. Dayan and co-authors note that insurance companies sometimes deny coverage for genetic testing for breast cancer risk, but that the costs of testing have decreased in recent years.

The study "supports the notion that genetic testing should be offered to all patients for whom unilateral abdominal-based tissue breast reconstruction is planned," Dr. Dayan and colleagues conclude. "Plastic surgeons should take an active role in discussing with patients and their care providers the implications of genetic testing in these cases."

Plastic and Reconstructive Surgery Editor-in-Chief Rod J. Rohrich, MD, agrees with the recommendation to test for high-risk gene mutations before surgery with breast reconstruction using an abdominal tissue flap. In a video commentary, he states:

Not having genetic testing has serious implications: it puts women at risk for future cancers, leaves family members unaware, and limits future reconstructive options."