“In hereditary cancer clinics, we see patients who are convinced that since they got breast cancer, they won’t get ovarian cancer,” said Dr. Kelly Metcalfe, a U of T professor in the Faculty of Nursing. Contrary to this belief, Metcalfe has determined that undergoing treatment for breast cancer does not lower the risk of developing ovarian cancer. Her study was published in the January 2005 issue of Gynecologic Oncology.
Metcalfe looked at families that had at least one case of breast cancer and at least one case of a mutation in either the BRCA1 or BRCA2 genes, which have been linked to breast cancer. A total of 491 women’s medical records and treatment histories underwent statistical analysis. “This was the largest cohort worldwide of women with hereditary breast cancer” studied to date, says Metcalfe.
She found that undergoing treatment for breast cancer did not significantly alter the risk of subsequently developing ovarian cancer. This is significant because the lifetime risk of developing ovarian cancer for people with BRCA1 mutations is 50 per cent and for BRCA2 mutations it is 27 per cent. Furthermore, 25 per cent of deaths in women in the early stages of breast cancer occur due to ovarian cancer. Women therefore should be more aware of the fact that even if they get breast cancer, they are still susceptible to ovarian cancer.
In order to prevent ovarian cancer, these women “should consider taking preventative measures, such as oophorectomy [removal of the ovaries and fallopian tubes],” says Metcalfe. Although such a procedure sounds drastic, Metcalfe said that it is quite benign, with the side effect of “putting women into menopause.” Ultimately, undergoing such a preventative procedure is much less risky than the possibility of developing ovarian cancer and most women to whom it is suggested accept it.
