Cancer of the colon and rectum: 30-year follow-up study.

This study reviews the course of all patients registered at the Saskatoon Cancer Clinic between 1949 and 1951, with histologically proven cancer of the colon or rectum. The data were abstracted, coded and analysed by life-table methods. Follow-up was complete to death or to 1982. There were 403 patients (58.3% were men). Cancer of the rectum accounted for 51% of the total, the sigmoid colon 22% and the cecum 10%. The primary tumour was resected by abdominoperineal resection, hemicolectomy or segmental colectomy in 63% of the patients; colostomy alone was performed in 21%. The overall survival was 31% at 5 years, 24% at 10 years, 15% at 20 years and 7% at 30 years from diagnosis. Many of the deaths in this relatively elderly group of patients were due to causes other than the cancer. Considering cancer-related causes of death only in patients with resectable lesions, the cumulative probability of survival at 5, 10, 20 and 30 years was 63% +/- 4%, 54% +/- 4%, 48% +/- 4% and 47% +/- 6%, respectively (probability +/- 1 standard error), for those without lymphadenopathy, and 14% +/- 3%, 12% +/- 2%, 10% +/- 2% and 9% +/- 3%, respectively, for those with involved nodes. Death from the cancer was rare after 10 years while deaths from competing causes continued to occur, at a near constant rate, for 30 years. The data suggest that the cancer was eradicated in one third of all patients, and in one half of patients in subgroups with no lymphadenopathy or with shallow primary lesions.