Mastectomy May Not Improve Long Term Chances of Surviving Breast Cancer

July 17, 2014 7:00 AM EDT

Researchers at the University of Minnesota confirm that when it comes to treating some forms of breast cancer, drastic surgery to remove breast tissue may not help in improving survival from the disease.

Reporting in the Journal of the National Cancer Institute, the scientists describe a model for calculating life expectancy based on recent rates of recurrent cancers among women with stage 1 or stage 2 disease. Although previous studies found that among women diagnosed with breast cancer in one breast, removing the other breast can lower risk of breast cancer in that breast by up to 90%, few studies have documented whether that also translated into greater survival of breast cancer, which can recur in other organs.

According to the researchers’ model, the overall difference in survival at 20 years after diagnosis for both women who had their opposing, unaffected breast removed and those who did not, was less than 1%.

The data confirm recent findings from a study of women with metastatic disease, which also showed that women who received additional surgery to remove lymph nodes and their breasts did not survive any longer than those who were treated with chemotherapy only. As TIME wrote about that study,

Researchers from Tata Memorial Hospital in Mumbai, India, recruited 305 women between 2005 and 2013, all of whom had metastatic breast cancer and had responded to six cycles of chemotherapy. The women were split into two groups. One group of 173 women received additional surgery and radiation treatment, and 177 did not. The women who received surgery had partial or total removal of their breasts and lymph nodes followed by radiotherapy.

After just over two and a half years, the scientists found no overall difference in survival between the two groups; in fact, there was a slight, but not significantly significant, increase in risk of death for the women undergoing surgery and radiation. The lack of difference remained strong even after the scientific team adjusted for the types of breast cancer the women had, and the extent to which their cancer had spread to other organs. The findings should provide more confidence to both doctors and patients who choose not to go under the knife or receive radiation in an effort to prolong their lives, since the evidence suggests that the added measures don’t provide significant benefit, and may only expose the women to more complications.

In the current study, the researchers note that survival is only one factor that women may take into account when debating whether to remove an unaffected breast. In an accompanying editorial, other researchers echoed the distinction, saying that quality of life and peace of mind factors may be important reasons for supporting the continued use of prophylactic mastectomy surgery.

Removing Both Breasts May Not Improve Survival From Breast Cancer

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