Abstract
Abstract only
4054
Background: Based on the results of intergroup trials, adjuvant chemotherapy has become the standard of care for patients with Duke stage C colon and Duke stages B and C rectal cancer. Although initiation of adjuvant chemotherapy soon after recovery from surgery is desirable, only few studies have examined whether a delay in starting adjuvant chemotherapy affect clinical outcomes. Our objective in this study is to determine the impact of timing of adjuvant chemotherapy on survival after resection of Duke stage C colon and Duke stages B and C rectal cancer. Methods: Study involves use of the information available from patients chart review in the province of Saskatchewan, Canada. Patients 18 years of age and older (median age 66 years), diagnosed with Duke Stage C colon and Duke stages B and C rectal cancer between 1993 and 2000 were included. Median followup was 54.8 months. All patients with rectal cancer received radiation treatment as per institution policy. Cox proportional hazards models were used to analyze the impact of timing of adjuvant chemotherapy on survival. Results: Among 701 patients eligible for study, 453 (64.6%) patients received adjuvant chemotherapy within 56 days of surgery (group I) and 248 patients (35.3 %) received adjuvant chemotherapy after 56 days of surgery (group II). Median time interval between surgery and the initiation of adjuvant chemotherapy in group I, and II were 41 days and 70 days respectively. Five year DFS for group I was 39% as compared to 37% for group II (HR 0.94, CI 0.76–1.16, p = 0.58). Median OS for group I was 97.5 months as compared to 68.9 months (HR 1.08, CI 0.85–1.37, p= 0.54). Age, histology and number of lymph nodes analyzed, were identified as independent prognostic factors in multivariate analysis. Conclusions: In this study, patients with Duke stage C colon and Duke stages B and C rectal cancer who received adjuvant chemotherapy within 56 days of resection has similar outcomes as compared to patients who received adjuvant chemotherapy after 56 days of resection.
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