CONTRALATERAL PROPHYLACTIC MASTECTOMY INCREASE COMPLICATION RATE 

NEW YORK (Reuters Health) May 03 - Women with early cancer in one breast who opt for prophylactic mastectomy of their healthy breast risk unnecessary complications that may impact the timing and delivery of adjuvant chemotherapy and radiation, researchers warn.

In a study of more than 4,200 breast cancer patients, they found that women making this choice had twice as many postoperative complications as women undergoing a single mastectomy.

The findings are significant because the risk of future cancer in the opposite breast of a unilateral breast cancer patient, without other risk factors, is "extremely low, less than 1% per year," study leader Dr. Fahima Osman from University of Toronto said. "There is no strong evidence that suggests that this procedure has a survival benefit in the majority of women with breast cancer."

It's "imperative" to discuss potential complications with women contemplating contralateral prophylactic mastectomy, Dr. Osman added.

She discussed the study findings Thursday during a media briefing at the American Society of Breast Surgeons (ASBrS) annual meeting underway in Chicago.

Dr. Deanna Attai, ASBrS board member and director the Center for Breast Care, Inc. in Burbank, California, who moderated the briefing, said the study is "very important as the mastectomy rate does seem to be increasing in this country. As more and more women are choosing prophylactic mastectomy, we do need to start looking at what the potential complications and risks of additional surgery are."

Using the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) database for the years 2007-2010, Dr. Osman and colleagues compared postoperative complication rates in 3,722 women who had unilateral mastectomy (UM) and 497 who had bilateral mastectomy (BM).

Dr. Osman said they employed a range of exclusionary criteria to achieve a "homogenous population" and controlled for several factors known to affect surgical complication rates, including body mass index, age, smoking status, hypertension, coronary artery disease, and chronic obstructive pulmonary disease.

They found a statistically significant higher wound complication rate (including infection and wound dehiscence) in the BM group (5.8% vs 2.9% in the UM group).The overall surgical complication rate was also higher in the BM group (7.6% vs 4.2%). The adjusted odds ratio for overall complications was 1.92 (p=0.001).

Being overweight and smoking were independent predictors of postoperative complications. Dr. Osman said she "certainly would advise" an obese women who smokes and is considering prophylactic mastectomy to look at these risks "carefully."

It's important to note, Dr. Osman said, that the analysis only looked at 30-day outcomes. "We don't know whether there are more complications associated with bilateral mastectomy beyond 30 days. Also, the cancer stage is not reported in NSQIP data. We tried to limit it to patients to early-stage breast cancer, however, we could still capture patients who had more advanced disease. We need further studies to examine the short-term complications of CPM (contralateral prophylactic mastectomy) and whether these complications significantly delay adjuvant treatment."

In a conference statement, Dr. Osman said that in the era of modern chemotherapy and endocrine therapy, women with early cancer in one breast and no other risk factors "would rarely benefit from a prophylactic mastectomy. However, it is important to note that women with genetic and other risk factors may have a clear benefit."