Validating cancer histories in deceased relatives.

BACKGROUND

A family history of cancer is a marker of familially shared genetic and environmental risk factors for cancer but is subject to inaccurate and biased reporting.

METHODS

In a case-control study of adult acute leukemia, we examined the accuracy of cancer reports in deceased first-degree relatives using death certificates and the National Death Index (NDI). We submitted information on 1058 deceased relatives to the NDI or civil vital statistics registries. Social security numbers were not available and identifying information was incomplete.

RESULTS

A death certificate was located for 70% of records sent to state registries but for only 32% of records submitted to the NDI. Death certificates confirmed 95% of relatives reported to be cancer-free and 83% of those reported to have any form of cancer. Confirmation of cancer of specific sites ranged from 50% for breast cancer and 54% for leukemia to 86% for prostate cancer.

CONCLUSIONS

State searches may be preferable to the NDI when identifying information is incomplete.