Study examines the association of BRCA1 gene, infertility and breast/ovarian cancer

Dec 14 2009

Westchester Medical Center Physician and Fertility Preservation Expert leads study examining the association of breast cancer genes, breast cancer and infertility

In a study published online this week in the leading cancer journal, Journal of Clinical Oncology, Westchester Medical Center Physician Dr. Kutluk Oktay, MD, Director, Division of Reproductive Medicine & Infertility concluded that mutations in the BRCA1 gene (gene associated with early onset breast cancer) are associated with early diminishment of egg reserve. This finding may, at least in part, explain the link between infertility and breast/ovarian cancer risks.

During the study, Dr. Oktay's team performed ovarian stimulation in 126 women with breast cancer for the purpose of fertility preservation by embryo or oocyte cryopreservation.

The results found that of the 82 women who met the inclusion criteria, 47 women (57%) had undergone BRCA testing, and 14 had a mutation in BRCA genes. In BRCA mutation-positive patients, low ovarian response rate was significantly higher compared with BRCA mutation-negative patients and with BRCA-untested women. All BRCA mutation-positive low responders had BRCA1 mutations, but low response was not encountered in women who were only BRCA2 mutation positive. Compared with controls, BRCA1 mutation -- but not BRCA2 mutation-positive women produced lower numbers of eggs.

It is estimated that, in the general population, one in every 1,000 women is BRCA mutation positive, and this incidence is as high as 2.5% in certain ethnic groups. Regardless of underlying mechanisms of early diminishment of egg reserve in BRCA1 mutation-positive women, the findings may have profound implications for the future fertility of a large number of women in the general population.

The study concludes that there is a novel association between low response to ovarian stimulation with fertility drugs and BRCA1 mutations, which suggests a possible link between infertility, and breast/ovarian cancer risks. The analysis of the BRCA gene in women with infertility and low response to ovarian stimulation may be worthwhile, especially when there is family history of breast and/or ovarian cancer. Larger studies are warranted to investigate the impact of BRCA mutations on fertility in general population.

Researchers have identified hundreds of mutations in the BRCA1 gene, many of which are associated with an increased risk of cancer. Women, particularly those in their mid 30's or older, who have an abnormal BRCA1 or BRCA2 gene, have an increased risk of developing breast/ovarian cancer and produce a significantly less number of eggs than normal. This is noteworthy factor as women put off pregnancy.