Use of adjuvant chemotherapy in stage C (III) rectal cancer: Comparison of data from matched patients in a teaching hospital's clinico-pathological database

Aims: Controversy continues regarding the treatment of patients with resectable rectal cancer, particularly in regard to the effects of adjuvant therapies on long-term survival. The benefits of adjuvant chemotherapy alone in patients with stage III rectal cancer after curative resection remain unclear. The aim of this study was to compare the overall survival of patients who had received adjuvant chemotherapy after resection of a stage III rectal cancer (111 patients) with the survival of a historical control group who had surgery alone before chemotherapy was introduced (129 patients). Methods: Treatment and outcomes data were drawn from a prospective hospital registry of consecutive patients who had a resection for stage III rectal cancer. Results: The estimated Kaplan-Meier overall 5-year survival rate in patients who received chemotherapy (68.7%, 95% CI 58.3-77.1%, log-rank P<0.001) was improved compared with the historical controls (40.5%, 95% CI 31.4-49.5%, log-rank P<0.001). No systematic differences between the treated and control group were found. Conclusion: This study has shown improved survival after adjuvant chemotherapy in patients with stage III rectal cancer as compared with historical controls treated by surgery alone. Hence, there could be subsets of patients whom when treated with surgery in a specialized surgical unit, may benefit from chemotherapy and spared the toxicities of adjuvant radiotherapy. This should be explored further in a cooperative trial group setting.