For the more than 310,000 women diagnosed with breast cancer each year, the fear of recurrence looms large. Questions often arise about whether a double mastectomy might provide better protection against the disease. However, a recent study suggests that removing both breasts offers no survival benefit compared to keeping one healthy breast.
The research, conducted by Dr. Steven Narod of Women’s College Hospital in Toronto and his colleagues, used data from over 661,000 U.S. women with unilateral breast cancer. Published in JAMA Oncology on Thursday, the study found that women who had a lumpectomy or mastectomy without removing the other breast had similar survival rates to those who opted for a double mastectomy.
The study revealed that the chance of developing cancer in the other breast was about 7 percent over 20 years. However, this statistic might not apply to women with BRCA1 or BRCA2 gene variants, which significantly increase cancer risk. For the 1 in 500 American women with these variants, a double mastectomy may be worth considering, according to cancer researchers.
The finding that double mastectomy doesn’t improve survival rates seems counterintuitive, admitted Dr. Narod. An editorial by Dr. Seema Ahsan Khan and Masha Kocherginsky of Northwestern University called it a conundrum. While previous smaller studies had similar conclusions, their methods were sometimes questioned. This new study, however, provides a more comprehensive analysis, said Dr. Angela DeMichele of the University of Pennsylvania.
Dr. Narod and his team reported that the 7 percent chance of developing cancer in the other breast was consistent regardless of the initial cancer’s stage. They calculated that 69 out of 1,000 women with unilateral breast cancer would develop cancer in the other breast within 20 years, significantly increasing their mortality risk.
Dr. Eric Winer, director of the Yale Cancer Center, noted that the new study aligns with previous research, suggesting no survival difference between lumpectomy, mastectomy, and double mastectomy. Dr. DeMichele emphasized that women have a real choice in treatment and that removing the second, healthy breast does not prevent the spread of cancer cells to other parts of the body. She highlighted the importance of chemotherapy and hormonal therapies in targeting these cells.
Dr. Khan acknowledged that while a double mastectomy might not be necessary for survival, some women choose it to avoid the anxiety of ongoing screenings and potential additional treatments. Others opt for the procedure for cosmetic reasons when undergoing reconstruction.
“The decisions are complex,” she said. “But if a second cancer occurs, there is still a good chance of survival.”
Dr. Winer stressed the importance of vigilant screening to detect any new cancers at the earliest possible stage.
