Reported symptoms, diagnostic delay and stage of colorectal cancer: a population-based study in Denmark

Objective The primary prognostic factor for colorectal cancer (CRC) is stage. Any association between symptoms, diagnostic delay and stage may have implications for the clinical course of the disease. We examined the association between symptoms and diagnostic delay and between symptoms and stage, and assessed whether the associations differed for colon cancer (CC) and rectal cancer (RC). Patients and methods Population-based prospective observational study based on 733 Danish CRC patients. Diagnostic delay and patients' reported symptoms were determined through questionnaire-interviews. Dukes' stage was obtained from medical records and pathology forms. Diagnostic delay was categorized into three delay groups: <= 60, 61-150 and > 150 days. Stage was classified into nonadvanced (Dukes' A and B) or advanced (Dukes' C and D) cancers. We calculated the frequency of the most frequently reported initial symptom or symptom complex for CC and RC patients, and evaluated the frequency of patients with different initial symptoms/symptom complexes in the three delay groups. For the most frequent initial symptoms/symptom complexes, we calculated the frequencies according to stage, and estimated the relative risk of having an advanced stage, with 95% confidence intervals. Results The most frequent initial symptoms/symptom complexes were very vague symptoms for CC and rectal bleeding for RC. For both CC and RC, rectal bleeding was significantly associated with nonadvanced stage. The relative risk of having an advanced cancer was 0.6 for monosymptomatic rectal bleeding and 0.7 for rectal bleeding combined with other symptoms. Conclusions Initial symptoms of CC were often very vague, making it difficult to identify a precise start date. The most frequent initial symptom/symptom complex for RC - rectal bleeding - was better defined. Rectal bleeding was significantly associated with nonadvanced CC and RC and a significantly decreased relative risk of having an advanced cancer.