Investigating the completeness of a histopathological cancer registry: Estimation by capture–recapture analysis in a French geographical unit Alpes-Maritimes, 2008

Introduction Cancer population studies require reliable and complete baseline data, which should theoretically be available by collecting histopathology records. The completeness of such a collection was evaluated using capture–recapture analysis based on three data sources concerning breast and colorectal cancers over an identical period and within the same geographical area. Method The total number of breast and colon cancer cases was estimated using capture–recapture analysis based on the number of cases which were common or not between sources recording screened, diagnosed and treated cancers in the French Alpes Maritimes district. Result The estimated total number of new cases of breast cancer diagnosed among Alpes Maritimes residents women aged 50–75 was 791 (95% CI: 784–797) in 2008. Of these 791 cases, 729 were identified through histopathology records, thus amounting to 92.2% completeness (95% CI: 91.5–93.0%). The total estimated number of new cases of colorectal cancer diagnosed among Alpes Maritimes residents aged 50–75 was 527 (95% CI: 517–536). Of these 527 cases, 481 were identified through histopathology records, thus amounting to 91.3% completeness (95% CI: 89.7–93.0%). Conclusion The estimated completeness of cancer records collected from histopathology laboratories was higher than 90% for new cases of breast and colorectal cancer within the age range concerned by the screening programme. A verified and validated histopathology data collection may be useful for cancer population studies.