Follow-up of a Large Prospective Cohort in the United States Using Linkage With Multiple State Cancer Registries.

All states in the United States now have a well-established cancer registry. Linkage with these registries may be a cost-effective method of follow-up for cancer incidence in multistate cohort studies. However, the sensitivity of linkage with the current network of state registries for detecting incident cancer diagnoses within cohort studies is not well-documented. We examined the sensitivity of registry linkage among 39,368 men and women from 23 states who enrolled in the Cancer Prevention Study-3 cohort during 2006-2009 and had the opportunity to self-report cancer diagnoses on a questionnaire in 2011. All participants provided name and birthdate, and 94% provided a complete social security number. Of 378 cancer diagnoses between enrollment and 2010 identified through self-report and verified with medical records, 338 were also detected by linkage with the 23 state cancer registries (sensitivity of 89%, 95% confidence interval (CI): 86, 92). Sensitivity was lower for hematologic cancers (69%, 95% CI: 41, 89) and melanoma (70%, 95% CI: 57, 81). After excluding hematologic cancers and melanoma, sensitivity was 94% (95% CI: 91, 97). Our results indicate that linkage with multiple cancer registries can be a sensitive method for ascertaining incident cancers, other than hematologic cancers and melanoma, in multistate cohort studies.