Comparison of acute toxicities between two postoperative concurrent chemoradiotherapy regimens of capecitabine with or without oxaliplatin in patients with stage Ⅱ and Ⅲ rectal cancer

Objective To compare the acute toxicities between two prospective, non-randomize phase Ⅱ trials on adjuvant radiochemotherapy of capecitabine with or without oxaliplatin in patients with stage Ⅱ and Ⅲ rectal cancer. Methods From March 2005 to November 2007,based on two fulfilled phase Ⅰ studies,two phase Ⅱ trials were launched respectively to further observe the tolerance and toxicity. In one tria1,118 patients were treated with concurrent capecitabine and radiotherapy (Cap-CRT trial), with radio-therapy of DT50 Gy/25 F/5 wks to the pelvis, and capecitabine at a dose of 1600 mg/m2/d(d1-d14,3 weeks per cycle). In the other trial, 90 patients received concurrent oxaliplatin, capecitabine and radiothera-py(Cap-Oxa-CRT trial), with the same radiotherapy schedule, while oxaliplatin at a dose of 70 mg/m2(d1, d8) and capecitabine of 1300 mg/m2/d(d1-d14,3 weeks per cycle). Results There was no significant difference in the delay of radiotherapy (10.2% vs 6.7%, X2=0.80, P=0.460) or chemotherapy (9.3% vs 19.1%, X2=4.80,P=0.090) between Cap-CRT and Cap-Oxa-CRT trials. Grade 1-4 leukopenia,diar-rhea and nausea were the most common acute side-effects in the both trials, accounting for 70.2%, 65.9% and 42.3%, respectively. When comparing with Cap-CRT trial, Cap-Oxa-CRT trial had significantly more grade 1-4 non-hemotological toxicities, mainly in Gl,including nausea (68.9% vs 22.0%, X2=46.90, P= 0.000), diarrbea(76.7% vs 57.6%, X2=13.50, P=0.009), fatigne(47.8% vs 13.7%, X2=18.90,P= 0.000), hand-foot syndrome (14.4% vs 4.2%, X2=7.10, P=0.029), and inappetence (50.0% vs. 27.9%, X2 = 25.70, P=0.000), but not in hematological toxities of leukopenia, anemia or thrombocytope-nia. Of all the patients,grade 3 and grade 4 toxicities were diarrhea(24.0% and 1.0%),leukopenia(4.3% and 0.0%),radiation-induced dermatitis(3.8% and 0.0%),cramping abdominal pain(1.0% and 0.0%) and fatigue(0.5% and 0.0%). Only grade 3 and 4 diarrhea was significantly more in Cap-Oxa-CRT trial than in Cap-CBT trial(33.0% vs 18.6%, X2=5.90,P=0.023). Conclusions For patients with stage Ⅱ and Ⅲ rectal cancer,both the postoperative concurrent radiochemotherapy regimens are tolerable,though Cap-Oxa-CRT trial has more grade 3 and 4 diarrhea.