The use of bilateral mastectomy (the removal of both breasts) to treat unilateral breast cancer is becoming increasingly common. In fact, the percentage of women choosing this option has increased from two percent in 1998 to 12 percent in 2011. However, according to a new study published in JAMA, bilateral mastectomy was not associated with lower mortality as compared to unilateral mastectomy, or local radiation plus breast-conserving surgery (a procedure, most commonly lumpectomy, in which only a section of the breast, including the tumor, is removed).
Researchers from the Cancer Prevention Institute of California and Stanford University School of Medicine used data from the California Cancer Registry. They looked at about 200,000 women with stage 0- to stage 3-breast cancer from 1998 to 2011. Looking at ten-year survival rates, they found that unilateral mastectomy was associated with higher all-cause mortality compared with breast-conserving surgery plus radiation. They also found a slight difference in mortality between bilateral mastectomy and unilateral mastectomy, but the difference was not significant.
Researchers are unsure as to why there is a slight difference in survival between women who opted for a unilateral mastectomy, as compared to those who opted for bilateral mastectomy, but they found that this treatment is much more common in racial/ethnic minorities and Hispanics and those with public/Medicaid insurance versus private insurance.
When faced with a new breast cancer diagnosis, many patients assume that they will achieve a survival advantage by pursuing the most aggressive surgical strategy, says Lisa Newman, director of the Breast Care Center at the University of Michigan in Ann Arbor. The California study refutes those assumptions.
And Scarlett Gomez, a research scientist at the Cancer Prevention Institute of California and Stanford University School of Medicine and senior author of the report adds, We need to make sure women are informed of all the pros and cons. The growth in mastectomies begs the question of what the thought process is that women are going through, and what kind of information are they offered to enable them to make the best decision possible.
