Background: Dukes' stage is the most important predictor of prognosis of colorectal cancer, but the association between delay of treatment (DT) and Dukes' stage is still controversial.
Methods: From 1 January 2001 to 31 July 2002, we conducted a population-based prospective observational study based on 733 Danish colorectal cancer patients. DT was determined through questionnaire-interviews, and Dukes' stage was obtained from medical records and pathological forms. DT was classified into three groups: short (0-60 days), intermediate (61-150 days) and long (>150 days) DT. Dukes' stage was classified into two groups: non-advanced (Dukes' stage A or B) and advanced (Dukes' stage C or D) cancer. Using relative risk (RR) the association between DT and stage was estimated, with short delay as the reference group.
Results: The RR of advanced cancer was 1.0 (95% confidence intervals (CI): 0.8-1.3) for colon cancer patients with an intermediate DT, and 1.1 (95% CI: 0.9-1.4) for patients with a long DT. For rectal cancer patients the RR of advanced cancer was 1.9 (95% CI: 1.1-3.1) for patients with an intermediate DT and 2.1 (95% CI: 1.3-3.4) for patients with a long DT.
Conclusion: DT was strongly associated with advanced stage of rectal cancer, but not of colon cancer.