The effect of duration of symptoms and other prognostic factors on survival was studied by interview using a population-based sample of 154 colorectal cancer patients. The authors found that symptom durations of up to approximately one year before diagnosis had no effect on survival. In addition, it was found that the total number of symptoms was a statistically significant predictor of survival, although no single symptom had a significant effect. Stage, sex, and site also were found to be significant predictors of survival, whereas age, socioeconomic status, and other factors were not predictive.