Race/ethnicity and accuracy of self-reported female first-degree family history of breast and other cancers in the Northern California Breast Cancer Family Registry

Background: Few studies have evaluated accuracy of self-reported family history of breast and other cancers in racial/ethnic minorities. Methods: We assessed the accuracy of cancer family history reports by women with breast cancer (probands) from the Northern California Breast Cancer Family Registry compared to two reference standards: personal cancer history reports by female first-degree relatives and California Cancer Registry records. Results: Probands reported breast cancer in first-degree relatives with high accuracy, but accuracy was lower for other cancers. Sensitivity (% correctly identifying relatives with cancer) was 93% (95% CI, 89.5-95.4) when compared to the relatives9 self-report of breast cancer as the reference standard and varied little by proband race/ethnicity and other demographic factors, except for marginally lower sensitivity for Hispanic white probands (87.3%, 95% CI, 78.0-93.1, P=0.07) than non-Hispanic white probands (95.1%, 95% CI=88.9-98.0). Accuracy was also high when compared to cancer registry records as the reference standard, with a sensitivity of 95.5% (95% CI, 93.4-96.9) for breast cancer, but lower sensitivity for Hispanic white probands (91.2%, 95% CI, 84.4-95.2, P=0.05) and probands with low English language proficiency (80%, 95% CI, 52.8-93.5, P <0.01). Conclusions: Non-Hispanic white, African American, and Asian American probands reported first-degree breast cancer family history with high accuracy, although sensitivity was lower for Hispanic white probands and those with low English language proficiency. Impact: Self-reported family history of breast cancer in first-degree relatives is highly accurate and can be used as a reliable standard when other validation methods are not available.