Lead author Steven Chen of the University of California, Davis, and co-author Steve Martinez, also a University of California, Davis, surgical oncologist, used data from a national cancer database for their study that involved 747 patients who previously received lumpectomy -- tumor removed -- and were diagnosed with cancer a second time in the same breast.

The study, published in the the American Journal of Surgery, found that women who had mastectomies had a 78 percent survival rate after five years, compared to women who had second lumpectomies who had a 67 percent survival rate. The 10-year survival rates were 62 percent for those who had mastectomies and 57 percent for those who had second lumpectomies, Chen said.

"We were surprised to find that so many women in our study -- almost one-quarter -- had received another lumpectomy rather than a mastectomy," Chen said in a statement. "It's likely that patients are asking for lumpectomies when their cancer is diagnosed a second time, and doctors are simply complying with that request. Whatever the reason, that decision can shorten life spans."