What are the BRCA mutations all about?
When we hear “BRCA,” many of us automatically think about breast cancer. After all, testing positive for the BRCA1 mutation is what motivated Angelina Jolie to undergo a preventative double mastectomy a few years ago—prompting more widespread, mainstream awareness of the role of the BRCA1 and 2 genes and what they mean for breast cancer risk. What we know now: while only about 12% of women in general develop breast cancer during their lives, it’s estimated that 55–65% of women with the BRCA1 mutation and 45% of women with the BRCA2 mutation will develop breast cancer before their 70th birthdays.
(These mutations are sometimes incorrectly called the “BRCA genes.” While we all have BRCA genes—which produce tumor suppressor proteins that fend off cancer by repairing damaged DNA—only some women inherit mutated BRCA1 or 2 genes, meaning that the cancer-preventing protein isn’t produced or doesn’t work.)
What we hear less often is that the BRCA gene also affects women’s risk of ovarian cancer: while the occurrence of ovarian cancer is only 1.3% in the wider population, it’s elevated to 11–17% for women with the BRCA2 mutation and 39% for women with the BRCA1 mutation.
It’s worth noting that, overall, most women diagnosed with breast and ovarian cancers don’t carry either of the BRCA mutations. Only about 1 in 500 women in the United States carry one of the mutations, though that number varies based on a woman’s ethnic background (Ashkenazi Jewish women, for example, have about 10 times the likelihood of carrying one of the mutations than the general population). But for the women that do, the risk of cancer is elevated enough that doctors take it pretty seriously.
How can women get tested for these mutations?
Experts recommend that women with a personal or family history of breast, ovarian cancer, fallopian tube, or peritoneal cancer—or those with family members that have tested positive for these genetic mutations—get tested for the BRCA1 and 2 mutations. (The good news is that, thanks to advances in genetic testing technology, new start-ups are offering the tests for just $50–350 compared with the previous price of about $4,000.)
But what if the tests come back positive—what should women do then?
There are a few options:
Extra (and extra-careful) breast and ovarian cancer screenings, such as mammograms and pelvic ultrasounds, offering earlier detection and treatment
Hormone therapy that has been shown to reduce the chance of breast cancer
Preventative mastectomy (breast removal) and/or salpingo-oophorectomy (removal of ovaries and Fallopian tubes)
While the latter option is the most extreme—and of course, comes with other potential risks—it also decreases the risk of cancer to near zero.
What does this mean for fertility and fertility preservation?
Let’s be clear when we say that there’s no evidence of a connection between BRCA gene mutations and an increased risk of infertility. Just having one of these mutations doesn’t mean much in terms of your fertility—studies have demonstrated that women with BRCA mutations have comparable AMH (Anti-Müllerian Hormone) levels to other women, meaning their ovarian reserve probably isn’t affected.
But as we’ve already discussed, cancer—or, more accurately, cancer treatment such as chemotherapy, radiation, and surgery—often puts women’s fertility at risk. It follows that women who test positive for the BRCA1 and 2 mutations (and therefore have a higher chance of cancer) also have a higher chance of losing their fertility as a result of cancer treatment. Additionally, women who choose to remove their ovaries and Fallopian tubes as a preventative measure—lowering their chances of breast cancer and nearly eliminating their chances of ovarian cancer—also eliminate the possibility of getting pregnant naturally.
That’s why many oncofertility (fertility and cancer) experts are now recommending that women who test positive for one of the BRCA mutations explore their options for fertility preservation. Women with the BRCA mutations who don’t choose surgery might consider freezing their eggs preemptively, to ensure the eggs frozen are as young and healthy as possible and to remove one obstacle to undergoing cancer treatment if they are diagnosed one day. And women who do choose preventative salpingo-oophorectomy may also want to explore egg freezing. The good news is that, even if a woman’s ovaries and Fallopian tubes are removed, she can still get pregnant through in vitro fertilization, a process in which the egg is fertilized in a lab and then transferred directly to the woman’s uterus, bypassing the ovaries and the Fallopian tubes completely.
And lastly, if a woman does choose to freeze her eggs and conceive via in vitro fertilization, she could do PGD (pre-implantation genetic diagnosis), or genetic testing of the embryos before they’re transferred. Children of women with the BRCA mutations who are conceived naturally will have about a 50% risk of inheriting the mutations. PGD gives women the option of transferring only embryos that aren’t carrying those mutations—offering the possibility of a healthier life to future generations.