Relationship of survival to stage of the tumour and duration of symptoms in colorectal cancer.

It has been suggested that reduction of diagnostic delay in symptomatic colorectal cancer will not improve survival. Published reports show varying effects of duration of symptoms both on stage of cancer and on survival. However, tumour stage can be measured only at the end of the symptomatic period and, therefore, conclusions cannot be drawn about early diagnosis of symptomatic colorectal cancer and its effect on survival. On current evidence, early diagnosis and treatment may improve survival and should be encouraged.