A population-based study of rectal cancer: Permanent colostomy as an outcome

Purpose: The objectives of this study are to describe the utilization of su rgery and of radiotherapy in the treatment of newly diagnosed rectal cancer in Ontario between 1982 and 1994, and to describe the probability of perma nent colostomy at any time after the diagnosis of rectal cancer, as an outc ome of the treatment of newly diagnosed rectal cancer. Methods and Materials: Electronic records of rectal cancer (International C lassification of Diseases code 154) from the Ontario Cancer Registry (n = 1 8,695, excluding squamous, basaloid, cloacogenic, and carcinoid histology) were linked to surgical records from all Ontario hospitals, and radiotherap y (RT) records from Ontario cancer centers. Procedures occurring within 4 m onths of diagnosis, or within 4 months of another procedure for rectal canc er, were considered part of initial treatment. Multivariate analyses contro lled for age, sex, and year of diagnosis. Results: Resection plus permanent colostomy was performed in 33.1% of cases , whereas local excision or resection without permanent colostomy was perfo rmed in 38.2%. Multivariate logistic regression demonstrated higher odds ra tios (OR) for resection plus permanent colostomy in all regions of Ontario relative to Toronto. The OR for postoperative RT following local excision o r resection without permanent colostomy varied among the regions relative t o Toronto (e.g., OR Ottawa = 0.59, OR Hamilton = 0.76, OR London = 1.25). T he relative risk (RR) of colostomy conditional upon survival within 5 years from diagnosis varied among regions relative to Toronto (e.g., RR Ottawa = 1.21, RR Hamilton = 1.20). Conclusions: There is regional variation in the utilization of resection wi th permanent colostomy, and in the utilization of postoperative RT among ca ses not undergoing permanent colostomy. Regions with higher initial rates o f resection plus permanent colostomy continue to experience higher probabil ity of permanent colostomy 5 years after diagnosis of rectal cancer. Higher initial rates of permanent colostomy may be malleable to interventions aim ed at improving overall outcomes. (C) 1999 Elsevier Science Inc.