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Study: Removing Breasts or Ovaries Appears to Effectively Prevent Cancer in High-Risk Women

Some women at high-risk of developing breast or ovarian cancer have made the difficult decision to have their breasts or ovaries surgically removed to reduce their risk of cancer. A new study appears to support the effectiveness of this option. In reviewing medical records of nearly 2500 women, researchers found that women who had a genetically high risk of breast or ovarian cancer and who opted for prophylactic surgery reduced their risk of developing cancer. However, preventive surgery remains a drastic and personal option that women should carefully discuss with their physicians and loved ones, along with alternative measures, based on their individual medical situation.  

BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) are two tumor suppressor genes that, when functioning normally, help repair damage to DNA (a process that also prevents tumor development). In 1994, researchers discovered that women who carry mutations of BRCA1 or BRCA2 are at higher risk of developing both breast and ovarian cancer than women who do not have these genetic mutations. Currently, women with BRCA1 mutations account for 5% of all breast cancer cases.

Women with BRCA gene mutations have an elevated risk of developing breast and ovarian cancer. In the current study, researchers reported that the lifetime of developing breast cancer is 56% to 84% for women with BRCA gene mutations. The risk of ovarian cancer ranges from 36% to 63% for BRCA1 mutation carriers and 10% to 27% for BRCA2 mutation carriers, according to the current study.

Women who test positive for BRCA1 or BRCA2 genetic mutations are often encouraged to consider preventive measures. These measures include increased cancer screening, chemoprevention (the use of drugs, chemicals, vitamins, or minerals), or prophylactic surgery to remove the breasts or ovaries.

Prophylactic surgery is a controversial procedure among members of the medical community. Many physicians do not believe that surgically removing a woman’s breasts or ovaries is appropriate unless it is performed as a treatment for cancer. However, some physicians believe that certain individuals at especially high risk of cancer who are very worried about developing cancer may benefit from having prophylactic surgery. According to a past statement from the American Cancer Society Board of Directors, “only very strong clinical and/or pathological indications warrant doing this type of ‘preventive operation.’”

The current study appears to support a reduced risk of breast and ovarian cancer among genetically-predisposed women who choose to have prophylactic surgery. Susan Domchek, MD, of the University of Pennsylvania School of Medicine and her colleagues reviewed records of 2,482 women who tested positive for mutations in the BRCA1 and BRCA2 genes in Europe and North America between 1974 and 2008. The women were followed up until the end of 2009.

Among the 247 women who underwent prophylactic mastectomies to remove their breasts, none developed breast cancer in the three years after surgery, compared with 98 of 1372 (or 7%) women diagnosed with breast cancer who did not receive mastectomies. Women who underwent prophylactic oophorectomies to remove their ovaries also had substantially reduced risks of ovarian cancer.

Despite the positive results of the study, an editorial accompanying the study emphasized that prophylactic surgeries are not the only option available to women at high risk of breast or ovarian cancer. In addition to increased screening and chemoprevention, new research is investigating ways to reduce the risk and improve treatment of these cancers. For some high-risk women who are very worried about developing breast or ovarian cancers, surgery may be a viable option, but it may not be best for others. Women are encouraged to discuss these issues and the full range of options with their physicians and loved ones.

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