Cancer survival analysis in Hamburg 1995-2003: assessing the data quality within a population-based registry

Population-based cancer survival analysis constitutes valuable reference material for the clinical field of oncology. The objectives of this study were to assess the quality of the Hamburg Cancer Registry's (HCR) database in this respect, to perform survival analyses by means of selected sites, and to evaluate the results in relation to prevalent opinions and external estimates.

Data quality was assessed by the proportion of cases documented as diagnosed at death, external estimates of completeness, reliability of follow-up, histological verification and information on stage. Included were first primary malignancies of the colon (ICD10 C18, n=4,544), female breast (C50, n=9,259), prostate (C61, n=5,707) and urinary bladder (C67, D09.0, n=3,148), diagnosed in Hamburg residents 1995-2003. Observed and relative survival (OS, RS) were estimated by site, sex, time, age and stage.

Regarding female breast cancer in Hamburg, high levels of data quality and completeness exist while the explanatory power concerning malignancies of the colon, prostate and urinary bladder is limited. Age-standardised 5-year relative cancer survival estimates amounted for female breast to 81%, for colon to 49% (male) and 52% (female), for prostate to 81% and for urinary bladder to 71% (male) and 62% (female).

The study demonstrates the capacities and limitations of an epidemiological cancer registry to produce convincing survival estimates for clinical use, under the terms of a voluntary case reporting system.