Study Shows Possible Reasons Why Many Women with a Low Risk of Developing Cancer in the Other Breast Choose a Double Mastectomy

Quality Care Symposium
November 27, 2012

A recent review of cancer statistics from the National Cancer Institute Surveillance Epidemiology End Results (SEER) database showed that more than two thirds of women with early-stage breast cancer who received contralateral prophylactic mastectomy (CPM; removal of the breast not affected with cancer to lower the risk of the cancer from coming back) had a very low risk of developing cancer in the other breast. In addition, a survey of women with breast cancer showed that women who chose CPM were much more worried about recurrence (return of the cancer) than those who chose not to have CPM.

For this study, researchers surveyed 2,245 women with newly diagnosed breast cancer and re-surveyed 1,525 of those women about four years later. The women who participated in this study had received lumpectomy (removal of the tumor and some of the surrounding tissue), unilateral mastectomy (removal of the breast with cancer), or CPM. Out of the 1,446 women who did not have a recurrence before the second survey, 35% had considered CPM and about 7% had received it. About 70% of women who received CPM had a very low risk of developing cancer in the other breast.

Women who have a higher risk of the cancer developing in the other breast often have at least two first-degree relatives with breast or ovarian cancer and/or have changes in BRCA1 and BRCA2 genes. In this survey, women who had those risk factors were more likely to choose CPM. However, worry about recurrence also caused women to choose CPM, as 90% of women who received CPM said they were “very worried about recurrence” compared with 80% of women who received a mastectomy for only the breast with cancer.

What this means for patients

“If worries about cancer recurrence are affecting a woman’s emotional well-being, perhaps contralateral prophylactic mastectomy would be the right choice, but our results clearly show that too many women are having unnecessary surgery,” said lead author Sarah T. Hawley, PhD, MPH, Associate Professor of General Medicine at University of Michigan. “Our findings also suggest that some women made the decision based on their misconception about the ability of CPM to reduce the risk of recurrence in the same breast. In everyday practice, this means that physicians need to understand the strong impact of worry about cancer recurrence in a patient’s decision making, and may need to do a better job of educating and reassuring women about their true risks of both cancer recurrence and of developing a new cancer.” Generally, women with breast cancer have less than a 1% risk of developing a new cancer in the other breast, whereas the risk of cancer coming back in the same breast or nearby lymph nodes is 8%. The risks of recurrence are higher in women with a family history of breast cancer and BRCA gene alterations.

Questions to Ask Your Doctor

  • What stage of breast cancer do I have?
  • What are my treatment options?
  • Can you explain the benefits and risks of a mastectomy? A lumpectomy?
  • What is the chance that the cancer will recur in the same breast or the other breast?

For More Information

Guide to Breast Cancer

The Genetics of Breast Cancer

Mastectomy – What to Know

Coping With Fear of Recurrence

Coping With Uncertainty