Accuracy of self-reported family history of cancer in a large case-control study of ovarian cancer.

OBJECTIVE

To evaluate the reliability of self-reported family history of cancer in first-degree female relatives and to examine possible determinants of accurate reporting.

METHODS

Women with ovarian cancer and controls were recruited between 1995 and 1999 and interviewed. The study comprised 579 cases and 1,564 controls with 6,265 first-degree female relatives. Self-reported familial cancer diagnoses were validated from registry data. Sensitivity, specificity, and kappa were calculated, and possible determinants were examined by logistic regression.

RESULTS

The sensitivity of self-reporting ranged from 0.78 to 0.90 for all cancers but was lower for self-reporting of most site-specific cancers, ranging from 0.29 to 0.94. The specificity of self-reporting ranged from 0.91 to 0.99 for cancer in general and from 0.99 to 1.00 for site-specific cancers. Type of relative, age at interview, and length of education influenced the sensitivity and specificity significantly. The odds ratio for ovarian cancer was higher when based on registry data than on self-reported data and was significant (OR = 2.58 vs. 1.56).

CONCLUSIONS

Cancer diagnoses in first-degree relatives are not always accurately reported by patients with ovarian cancer or by controls. The results indicate that studies of associations with family cancer history should validate self-reported family cancer diagnoses as carefully as possible.