Postoperative Chemotherapy Might be Indicated on Patients with Pathological Stage II Rectal Cancer after Preoperative Concurrent Chemoradiotherapy

Abstract

Purpose. Preoperative concurrent chemoradiotherapy for rectal cancer increases the incidence of down-staging and pathological complete response. This study examined the hypothesis that patients with pathological stage Ⅱ rectal cancer would benefit from postoperative adjuvant chemotherapy after preoperative concurrent chemoradiotherapy. Methods. Between July 2000 and December 2004, 99 patients with clinical stage Ⅱ and Ⅲ rectal cancer who received preoperative concurrent chemoradiotherapy followed by radical surgery were enrolled. Preoperative concurrent chemoradiotherapy involved a radiation dosage of 45 Gy in 20 fractions and oral tegafur-uracil and leucovorin. Regimens for adjuvant chemotherapy were infusional 5-fluorouracil (3000 mg/m^2) and leucovorin (150 mg/m^2) biweekly for 12 cycles or oral tegafur-uracil (300 mg/m^2/day) and leucovorin (60 mg/day) 3 weeks per month over a 6-month period. Adjuvant chemotherapy was arranged for patients with pathological stage Ⅲ cancer. Basic characteristics were analyzed using the chi-square test. Survival was examined with Kaplan-Meier curves and comparisons were performed using the log-rank test. Results. Five-year overall survival and disease-free survival percentages were 75.0 and 57.1 for patients with pathological stage Ⅱ, and 86.4 and 67.5 for patients with pathological stage Ⅲ, cancers, respectively. Patients with pathological stage Ⅱ rectal cancer who did not receive adjuvant chemotherapy had relatively poorer overall and disease-free survivals compared to those with pathological stage Ⅲ cancer who received adjuvant chemotherapy (p=0.058 and 0.333, respectively). Conclusion. Alarge prospective study is indicated to confirm the value of adjuvant chemotherapy for patients with pathological stage Ⅱ rectal cancer after concurrent chemoradiotherapy and radical surgery.