Changes in diagnostic investigation and improved detection of colon cancer, Manitoba 1964-1984

Detection of colon cancer has improved in Manitoba over the last 20 years with decreases in diagnostic delay and failure. Between 1981 and 1984 diagnostic delay, resulting from initial false-negative examinations, occurred in 5.7% of patients. Diagnostic failure, because all investigations were negative in patients found to have cancer of the colon within one year, was 0.66%, compared with 9.5% and 5.8% respectively between 1964 and 1969. In the intervening time double-contrast barium examinations and colonoscopy were introduced and became more widely used, with a corresponding decline in single-contrast examinations. The mortality rate in the general population was unchanged despite an increased incidence, while 1980 survival rates suggested that women cancer patients were living longer than previously as well as longer than their male counterparts.