U Of T Study Identifies Women At Risk For Ovarian Cancer

Main Category: Ovarian Cancer
Article Date: 21 Dec 2004 - 15:00 PDT


Women with a genetic predisposition to breast cancer who are successfully treated for the disease may still be at high risk for ovarian cancer, says a University of Toronto study.

"In hereditary cancer clinics, we see patients with mutations in the BRCA1 or BRCA2 genes who are convinced that since they got breast cancer, they won't get ovarian cancer," says Kelly Metcalfe, a U of T professor of nursing and lead author of the study published in the January 2005 issue of Gynecologic Oncology. "It's not true that having breast cancer lowers the lifetime risk of ovarian cancer for these women. They should consider taking preventive measures, such as oophorectomy (removal of the ovaries and fallopian tubes), because they are still at a very high risk of developing ovarian cancer after breast cancer."

The BRCA1 and BRCA2 mutations are present in about one of every 250 women, and even more prevalent in women of Ashkenazi Jewish background, says Metcalfe. Women who have mutations in either of these genes have up to an 87 per cent lifetime risk of developing breast cancer. BRCA1 carriers have a 54 per cent lifetime risk of developing ovarian cancer; for BRCA2 carriers, the risk is 23 per cent.

Metcalfe and her colleagues arrived at their conclusions after examining the cancer pedigrees of families at 10 cancer genetics clinics and identifying those families where a mutation was documented and at least one case of breast cancer was recorded. They reviewed medical records for 449 women who were diagnosed with breast cancer between 1975 and 2000 -- "the largest cohort worldwide of women with hereditary breast cancer," says Metcalfe. The researchers then conducted a statistical survival analysis to arrive at their conclusions.

"This is a concern to us, because a lot of these women present early with stage one breast cancer and have a very good chance of survival," she says. "We found that 25 per cent of deaths in women with early stage breast cancer were due to a subsequent ovarian cancer and this is worrisome to us as clinicians. The prognosis for surviving ovarian cancer is much lower and there are ways to prevent ovarian cancer from happening."

Metcalfe suggests that BRCA1 and BRCA2 carriers who have been diagnosed with breast cancer should consider undergoing an oophorectomy in their 40s, because ovarian cancer is usually diagnosed when women are in their 50s.

Other researchers who contributed to this study include Dr. Steven Narod, a professor in the U of T Department of Public Health Sciences and director of the familial breast cancer research unit at the Centre for Research in Women's Health; Ping Sun, a biostatistician at the Centre for Research in Women's Health; Drs. Ellen Warner and Andrea Eisen, professors in the U of T Department of Medicine and clinicians at Sunnybrook and Women's Health Sciences Centre; Ivo Olivotto, B.C. Cancer Agency; William D. Foulkes, McGill University; Parviz Ghadirian, Centre Hopital de Universit� de Montreal; Henry T. Lynch, Creighton University School of Medicine, Omaha, Neb.; Nadine Tung, Beth Israel Deaconess Medical Center, Boston, Mass.; Olufunmilayo Olopade, University of Chicago; Barbara Weber, University of Pennsylvania; and Jane McLennan, University of California-San Francisco.

The study was funded by the U.S. Department of Defense, which has special funding available for breast cancer research.

CONTACT:
Kelly Metcalfe - kelly.metcalfe@utoronto.ca
Elaine Smith - elaine.smith@utoronto.ca
Faculty of Nursing U of T Public Affairs
416-978-2851
416-978-5949

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