Evaluating complication rate for removal of one or both breasts in patients with breast cancer

In this study, researchers examined whether breast cancer patients who chose to have preventive removal of both breasts (bilateral mastectomy or BM) experience more post-surgery complications than patients who have removed only the cancer-affected breast (unilateral mastectomy or UM).

Most women with early breast cancer undergo surgery to remove the cancer. Typically, if the cancer is only confined to the breast tissue, this surgery does not remove the whole breast. This is called breast conserving surgery. However, some women chose to undergo more intensive surgeries, such as removing the entire affected breast (UM) to make sure that all cancer is gone and to prevent a recurrence (return of the cancer). Furthermore, since many breast cancers can reoccur in the opposite breast, the removal of both breasts (BM), when only one breast is affected by cancer, is increasingly common. This surgery is also known as a contralateral prophylactic mastectomy. Because BM is a more extensive surgery than a UM, it could result in more complications. Therefore, it is important to understand the risks of BM as compared to UM, so that doctors and patients can balance these against their benefits before deciding the most appropriate treatment.

Researchers compared the frequency of complications in the first 30 days after breast removing surgery among 4,219 breast cancer patients. 88.2% of these patients received a UM and 11.8% underwent a BM. The likelihood of developing a complication after BM was twice as high compared to UM (5.8% versus 2.9%), despite the fact that patients in the UM group tended to be older and were more likely to suffer from diabetes. Regardless of surgery type, patients who were overweight/obese or smokers were more likely to experience post-surgical complications.

In summary, compared to UM, BM is significantly more likely to result in surgical complications in breast cancer patients.

Because the researchers only compared outcomes during the first 30 days after surgery, this study is not able to assess how UM or BM affects survival. Further studies are needed to determine survival outcomes for patients who undergo UM or BM as treatment for breast cancer.

Talk to your doctor about the risks and benefits of breast-conserving therapy, UM and BM in your situation.