An observational study, published online in the Journal of the National Cancer Institute, revealed that it's not beneficial for the vast majority of women affected with breast cancer, to undergo preventive surgery to remove the unaffected breast as the preventive surgery on the opposite breast had little survival benefit, because patients either die from the cancer or from other medical conditions.

Researchers at the University of Texas M. D. Anderson Cancer Center reported that an analysis of more than 100,000 patients showed a survival benefit of just 6% among those who opted to have a double mastectomy.

“It's important for women to understand that, except for one subset of breast cancer patients, they don't need to do this”, said Dr. Isabelle Bedrosian, an M. D. Anderson Professor of Surgical Oncology.

The study found that a double mastectomy offers a slight benefit to patients aged 50 and younger but it did not find any benefit among patients 60 or older.

The increase in percent of women having a double mastectomy attributes to earlier cancers; genetic tests and better plastic surgery techniques which make reconstructive surgery appealing.

Dr. Victor Vogel, National Vice President for Research at the American Cancer Society said, “In the vast majority of women older than 50 with ER-positive disease, prudent waiting is probably the most appropriate”.