To cut, or not to cut? Women at high risk for developing breast cancer often struggle with their options, particularly with the choice of whether or not to undergo prophylactic mastectomy. And justifiably so: Removing your breasts to cut your cancer risk can seem awfully drastic, especially considering that many high-risk women will never develop breast cancer, that even after mastectomy the risk of developing breast cancer isn’t nil, and that surgery carries its own risks. And there are certainly other prevention options, from stepping up screening to taking chemopreventive drugs like tamoxifen. On the other hand, preventive mastectomy does dramatically improve one’s odds. For women with the BRCA-1 and BRCA-2 genetic mutations — who tend to get a more aggressive form of the disease and who have a 55 to 70 percent chance of developing breast cancer by age 70 — double mastectomy can lower their risk by as much as 90 percent. But attractive numbers don’t make mastectomy right for everyone, or an easy choice for those women who do opt for surgery.
Here to complicate the picture is some good, surprising news from the New England Journal of Medicine: A long-term study by researchers from Israel’s National Cancer Control Center found that among breast cancer sufferers, carriers of BRCA mutations have similar 10-year survival rates to non-carriers. In other words, BRCA carriers are more likely to develop breast cancer, but carriers with cancer aren’t more likely to die of the disease.
As the Wall Street Journal reported Thursday, “The finding is somewhat of a surprise, as carriers of the mutant genes tend to develop a more virulent form of the disease that strikes before age 50, and can be resistant to certain types of treatments.” And it’s worth noting, as Reuters does, that researchers observed “a slight difference in the death rate five years after diagnosis, and the tumors among women with BRCA1 or BRCA2 tended to be more aggressive. Of the noncarriers who died from breast cancer, 68 died within five years, versus 88 percent for women with BRCA1 and 77 percent for BRCA2 mutations.” Overall, though, the National Cancer Institute’s Patricia Hartge, who wrote a NEJM editorial to accompany the study report, called the findings “generally reassuring” for carriers of BRCA mutations.
Hartge did flag what she called “a disturbing footnote” in the study results, though: A small number of subjects died within 10 years of their diagnosis even though their tumors were small and their lymph nodes were unaffected. This strange stat contradicts what we think of as the typical cancer progression — and serves as a reminder that when it comes to breast cancer, there’s still much we don’t know.