BACKGROUND - Identification of individuals at high risk for colon and breast cancer requires an adequate family history assessment and can influence cancer screening and genetic testing decisions. Little data exist that evaluate the completeness of the family history interview in primary care.
METHODS - Retrospective chart review of 995 new patient visits to 28 primary care physicians evaluating the completeness of the family cancer history for colon or breast cancer. Family history information was evaluated for inclusion of age at diagnosis, degree of kinship, and specification of disease of interest.
RESULTS - Family history information on cancer diagnoses was collected on 679 (68%) of the patients. Specific information regarding the individual affected and the cancer diagnosis was present in 414 (61%) of the records. Affected first-degree relatives were more likely to have their age of cancer diagnosis recorded than second-degree relatives (39%, 95% confidence interval [CI]=34%-44% vs 16%, 95% CI=12%-20%). Age at diagnosis of cancer in first-degree relatives was documented in 51% of colon cancers, 38% of breast cancers, and 27% of ovarian cancers. Only 17% of individuals who meet criteria for early-onset breast cancer genetic testing were referred for genetic services.
CONCLUSIONS - Adequate cancer risk assessment using family history information requires age at cancer diagnosis and specification of a cancer diagnosis. Age at diagnosis was frequently missing from family history assessments, which could have a potential impact on identification of high-risk individuals. When family history information does identify high-risk individuals, only the minority are referred for genetic services.