A gene mutation that is linked to a greater risk of breast cancer may also be tied to potential fertility problems, researchers report.
The BRCA1 gene mutation, which raises the risk of breast cancer by 80 percent, may be linked to having fewer eggs in the ovaries as a woman ages, the Australian investigators said. But a cause-and-effect relationship was not proven.
“A woman who is a BRCA1 carrier at age 35 has ovaries that look more like the ovaries of a 37-year-old, non-BRCA1 carrier,” she said.
Women with this mutation shouldn’t wait too long to start a family, according to Phillips. These women should plan on having children in their 20s and early 30s, and not wait until their late 30s and 40s, she suggested.
“The fertility of a woman at that age is already lower, and the fertility of these women may be even lower.
The researchers discovered that the BRCA1 gene mutation is tied to a 25 percent lower level of the anti-Mullerian hormone (AMH), which indicates the number of eggs left in a woman’s ovaries.
This effect was not seen, however, in women with the BRCA2 mutation, which is also linked to an increased risk of breast cancer.
Women who carry the BRCA1 and BRCA2 gene mutations have a higher risk of cancers in the breast, ovaries, fallopian tubes and peritoneum, Phillips said.
The cancer risk increases with age and is generally higher for those with the BRCA1 mutation than for those with the BRCA2 mutation, researchers have found.
About one in 500 women in the United States has a mutation in either the BRCA1 or BRCA2 gene, according to the U.S. Centers for Disease Control and Prevention.
If either parent had a BRCA1 or BRCA2 gene mutation, the odds of having the same gene mutation are 50 percent, according to the U.S. National Cancer Institute (NCI).
Because BRCA1 and BRCA2 gene mutations are relatively rare, most experts say that genetic testing of individuals who do not have cancer should be performed only when the person’s family history warrants it, the NCI says.
Women who carry BRCA mutations are faced with at least three difficult dilemmas:
“First and foremost is the concern that they have a very high chance — over 80 percent — of developing breast cancer, and are at a markedly increased risk for developing ovarian cancer — up to 63 percent for BRCA1 and 27 percent for BRCA2.
Second is the speeding up of their “biological clock,” which is reset by their genetic makeup.
“As it is, BRCA carriers feel the urgency to conceive and complete their family before they go through the inevitable removal of their tubes and ovaries.
Third, BRCA carriers have a 50 percent risk that their children will inherit the mutated gene, he added.
“Reproductive medicine has geared up to address all BRCA-related issues to benefit the carriers, as well as their future children,” Hershlag said.
BRCA carriers can undergo in vitro fertilization and the embryos can be tested for the BRCA1 or BRCA 2 gene mutations, maximizing the patient’s potential to conceive and eliminating the BRCA gene in the next generation, he explained.
“With the increased detection of cancer genes and cutting-edge reproductive technologies, we should be able to make a huge impact and decrease the occurrence of many cancers in generations to come.
