Spontaneous and therapeutic abortions and the risk of breast cancer among BRCA mutation carriers
1 The Suzanne Levy Gertner Oncogenetics Unit, The Chaim Sheba Medical Center, Tel-Hashomer, Israel, and the Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
2 Centre for Research in Women's Health, Bay Street, Women's College Hospital, University of Toronto, Canada
3 Department of Nutritional Sciences, University of Toronto, Ontario, Canada
4 Hereditary Cancer Center, Pomeranian Medical University, Szczecin, Poland
5 Department of Preventive Medicine and Public Health, Creighton University School of Medicine, Omaha, NE, USA
6 Epidemiology Research Unit, Research Centre, Centre Hospitalier de l'Universitaire Montréal, CHUM Hôtel Dieu, Département de Nutrition, Faculte du Medicine, Quebec, Canada
7 Epidemiology Division, Department of Medicine, University of California, Irvine, USA
8 Lombardi Cancer Center, Georgetown University Medical Center, Washington, USA
9 Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, USA
10 Departments of Medicine, Human Genetics, and Oncology, McGill University, Montréal, QC, Canada
11 Department of Cancer Genetics, Norwegian Radium Hospital, Oslo, Norway
12 Familial Ovarian Cancer Clinic, Princess Margaret Hospital, Toronto, ON, Canada
13 British Columbia Cancer Agency, Vancouver, BC, Canada
14 Institute of Genetics, Rambam Medical Center, Haifa, Israel
15 London Regional Cancer Centre, London, ON, Canada
16 Division of Population Science, Fox Chase Cancer Center, Philadelphia, PA, USA
17 Beth Israel Medical Center, Boston, MA, USA
18 Toronto-Sunnybrook Regional Cancer Center, Toronto, ON, Canada
19 Center for Clinical Cancer Genetics, University of Chicago, Chicago, IL, USA
20 Gynecology Oncology, Cedars Sinai Medical Center, Los Angeles, CA, USA
21 Hereditary Cancer Program, Division of Human Genetics, Children's Hospital Medical Center, Cincinnati, OH, USA
22 Dana Farber Cancer Institute, Boston, MA, USA
23 National Cancer Control Center, Carmel Medical Center, Haifa, Israel
24 Internal Medicine/Medical Genetics, WCM University of Alberta, Edmonton, AB, Canada
25 Clinical Cancer Genetics Program, Comprehensive Cancer Center, Division of Human Genetics, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
26 Department of Human Genetics and Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
27 Strang Cancer Prevention Center, New York, NY, USA
Breast Cancer Research 2006, 8:R15 doi:10.1186/bcr1387Published: 21 March 2006
BRCA1 and BRCA2 mutation carriers are at increased risk for developing both breast and ovarian cancer. It has been suggested that carriers of BRCA1/2 mutations may also be at increased risk of having recurrent (three or more) miscarriages. Several reproductive factors have been shown to influence the risk of breast cancer in mutation carriers, but the effects of spontaneous and therapeutic abortions on the risk of hereditary breast cancer risk have not been well studied to date.
In a matched case-control study, the frequencies of spontaneous abortions were compared among 1,878 BRCA1 mutation carriers, 950 BRCA2 mutation carriers and 657 related non-carrier controls. The rates of spontaneous and therapeutic abortions were compared for carriers with and without breast cancer.
There was no difference in the rate of spontaneous abortions between carriers of BRCA1 or BRCA2 mutations and non-carriers. The number of spontaneous abortions was not associated with breast cancer risk among BRCA1 or BRCA2 mutation carriers. However, BRCA2 carriers who had two or more therapeutic abortions faced a 64% decrease in the risk of breast cancer (odds ratio = 0.36; 95% confidence interval 0.16–0.83; p = 0.02).
Carrying a BRCA1 or BRCA2 mutation is not a risk factor for spontaneous abortions and spontaneous abortions do not appear to influence the risk of breast cancer in carriers of BRCA1 or BRCA2 mutations. However, having two or more therapeutic abortions may be associated with a lowered risk of breast cancer among BRCA2 carriers.