Marked rise in contralateral prophylactic mastectomies seen in US

October 23, 2007

NEW YORK (Reuters Health) - From 1998 through 2003, the rate of bilateral mastectomies among women with cancer in one breast more than doubled, according to a report in the October 22nd online issue of the Journal of Clinical Oncology.

"Many surgeons had noticed that more women were requesting double mastectomy for treatment of the cancer in only one breast. So, we weren't surprised by the overall trend, but we were very surprised by the magnitude," lead author Dr. Todd M. Tuttle said in an interview with Reuters Health.

What is driving this trend will require further studies, added Dr. Tuttle, from the University of Minnesota in Minneapolis. In the meantime, he advised, it is critical that physicians be aware and inform their patients that "although there may be sound reasons for undergoing double mastectomy (avoidance of future mammograms and preventing a new cancer), the procedure does not improve breast cancer survival."

The new study involved an analysis of data for 152,755 patients who were diagnosed with unilateral breast cancer between 1998 and 2003 and entered in the Surveillance, Epidemiology, and End Results (SEER) database.

Overall, 4969 patients elected to undergo contralateral prophylactic mastectomy. The rates of the operation were 3.3% among all surgical patients and 7.7% among mastectomy patients.

The overall rate of contralateral prophylactic mastectomy climbed from 1.8% in 1998 to 4.5% in 2003, the report indicates. Among mastectomy patients, the rate rose from 4.2% to 11.0%. These trends were noted for all cancer stages and were still apparent at the end of the study period.

Correlates of undergoing contralateral prophylactic mastectomy included younger patient age, non-Hispanic white race, lobular histology, and a prior cancer diagnosis, the researchers found. Large tumor size was associated with an increase in the overall rate of the procedure, but with a decrease in the rate among mastectomy patients.

"The main unanswered question from this research is: why are more women choosing to undergo double mastectomy?" Dr. Tuttle said. "For our next research project, we will interview breast cancer patients before and after surgery to determine what factors influenced their surgical decisions. We will also interview patients' surgeons to determine their advice."