Breast and ovarian cancer: the forgotten paternal contribution.

Five to 10% of all cases of breast and ovarian cancer are attributed to a heritable genetic predisposition. Transmission of BRCA1 and BRCA2 mutations is equally likely through maternal or paternal lineage; however, fewer referrals to cancer genetics clinics appear to be made for a paternal, than maternal, family history of breast and/or ovarian cancer. To examine this potential bias, a retrospective review of 315 patient and family charts was conducted by one familial cancer clinic in Toronto, Canada. Referral letters, risk estimates, and family histories were analyzed to identify significant differences between patients referred with maternal and paternal family histories. It was determined that patients are approximately five times more likely to be referred with a maternal family history of breast and/or ovarian cancer as compared to those with a paternal family history (p = <.0001). Individuals with a paternal family history were found to have a different, and higher, pattern of risk estimates (p = .00064). No significant difference was seen between the type of referrals sent by general practitioners, oncologists, and gynecologists. Recommendations to increase the awareness of paternal family history in assessing cancer risk are provided.