Background: Quality-controlled documentation and evaluation of long-term course of disease is essential for measuring the outcome quality in the care of cancer patients. This project, based on the ongoing clinical cancer registry of the Comprehensive Oncology Centre (COC) Stuttgart, was aimed to integrate a long-term follow-up documentation and to compare outcome quality between centres of the OCC.Methods: In a prospective, non-randomised, multi-centred, registry-based cohort study overall survival, disease free survival and quality of life were evaluated as indicators of outcome quality. The study included all patients suffering from breast, colon or rectum cancer, who were treated with curative intent in one of the centres of the OCC between Sep 30, 2003, and Dec 31, 2008. Cox regressions were used for the statistical evaluation of differences between centres.Results: Patients suffering from breast cancer (n = 3,213), colon cancer (n = 1,216) and rectum cancer (n = 847) were eligible for the analysis. They were treated in 10 of 13 centres of the OCC. Statistically significant differences in the overall survival could be demonstrated between centres.Discussion: This project initiated a regular comparative evaluation of the outcome quality and showed that there are statistically significant differences between centres. Based on these findings, the benchmarking process will have to be further developed and elaborated.