You may have recently seen that 72 new mutations were discovered
in a global breast cancer study conducted by 300 institutions all over the world. If you're a breast cancer fighter or survivor, you might wonder what it means for you. If you have been tested before, you might wonder what to do now.
Here are three reasons why you should care:
Because the Link Between Genetics and Breast Cancer Risk Is Already A Big Deal
Angelina Jolie’s experience with BRCA1
was an eye opener for many women to realize the relevancy of genetic testing and cancer risk . BRCA1 and BRCA2 are tumor suppressor genes, so testing positively for mutations in these genes is linked to a significantly higher risk of breast and ovarian cancer (with a slightly higher risk with people testing positively for BRCA1 mutations). A woman with a BRCA1 mutation might have a 55-65% risk of breast cancer by the age of 70, while the risk is about 45% for a BRCA2 mutation. Men with these mutations are at increased risk of male breast cancer. For ovarian cancer, the skew is 39% of women with a harmful BRCA1 mutation and 11-17% for BRCA2.
Disappointingly though, it was recognized early that BRCA1 and BRCA2 mutations only explained a tiny fraction of inherited breast cancers. That's where this new study has a profound impact.
Because the Net For Gene Mutations Linked To Cancer Just Got A Lot Bigger. And That's Good
While it may sound terrible to say there are 72 new items to add to your "cancer scare" list (rounding up to 180 known single nucleotide polymorphisms, or SNPS, associated with breast cancer), this is a huge win for cancer prevention.
Rather than looking at just two individual genes, genome-wide studies (IE the complete set of DNA present in a human) allows researchers to screen for all
potential genes linked to higher breast and ovarian cancer risk. These results will allow anyone concerned about their genetic predisposition to inheriting cancer, or their risk of a recurrence, to determine their actual risk by a much more accurate list of mutations to watch out for.
An individual with a strong family history of breast and/or ovarian cancer who tested negative for BRCA1 and BRCA2 mutations should consider asking their doctor if more testing might be helpful. If there were other mutations found, it would be helpful for the individual and their blood relatives to know. Options to reduce risk can be discussed including surgery (like double mastectomy) or taking medications. In some cases, there can be more aggressive breast cancer screening such as with MRIs as well as mammograms to pick up cancer early.
Because It Proves That Genetic Counseling Is More Important Than Ever
It bears highlighting that these new SNPs are not weighed equally - most individual variations are associated with small increases in risk, which is different from the more rare and significantly more dangerous mutations in BRCA1 and BRCA2. An individual going through genetic testing nowadays should meet with a genetic counselor before testing, and after as well if there are any positive results.
The conclusions of the researchers was that these new SNPs could be used for early detection and prevention of breast cancer and allow people to make more informed choices about treatment. For example, this discovery may result in a more aggressive focus on cancer screening, rather than surgical removal of breast or other organs if the risk is felt to be small and if one is comfortable with that.
If you're interested in genetic testing, check out the National Society of Genetic Counselors to find a genetic counselor near you.
Photo courtesy of Drew Hays.