A study on the maximal tolerated dose of oxalipiatin in a concurrent radiotherapy and chemotherapy protocol for postoperative rectal cancer patients / 中华普通外科杂志

ABSTRACT

Objectives To determine maximal tolerated dose(MTD)and dose-limiting toxicity (DLT) of oxaliplatin(L-OHP)when combined with constant dosing of 5-Fu、Lv and concurrent radiotherapy in postoperative patients with rectal cancer.Methods A total of 21 patients with stage Ⅱ or Ⅲ rectal adenocarcinoma after curative surgery were treated with radiotherapy to a total dose of 50 Gy in 5 weeks.L-OHP was administered at a dosge of 45 mg/m2(n=3),55 mg/m2(n=3),65 mg/m2(n=3),75 mg/m2(n=6),and 85 mg/m2(n=6)once a week for 2 weeks(first cycle)followed by a second cycle after a 14-day break.5-Fu and LV at a fixed dose of 5-Fu 300 mg/m2 ivdrip for 2 h,then 500 mg/m2 ivdrip within 22 h,d1,d2.LV 200 mg/m2 ivdrip 2 h d1,d2.DLT was defined as grade Ⅲ or Ⅳ hematologic and nonhenmologic toxicity. Results Grade Ⅰ-Ⅲ leukopenia,diarrhea,and nausea/vomiting were the most common toxic side effects.and most were of grade 1-2.DLT was first observed in 2 of 3 patients at 75 mg/m2(1 of grade Ⅲ diarrhea and 1 of grade Ⅲ leukopenia).L-OHP at dosage of 85 mg/m2 caused DLT in 4 of 6 patients(2 of grade Ⅲ leukopenia and 1 of grade Ⅲ diarrhea and 1 of grade Ⅲ diarrhea).Conclusions Diarrhea was the most common dose-limiting toxicity(DLT).Tlle maximal tolerated dose(MTD)of L-OHP in this setting was 75 mg/m2 which was comparable to the maximal tolerated dose of L-OHP seen in the neoadjuvant setting.