Safety and efficacy of a modified XELOX adjuvant regimen for patients with operated stage III colon cancer: a Chinese single-center experience

Background A fixed 8-cycle oxaliplatin and capecitabine (XELOX) regimen has been the standard adjuvant therapy for patients with stage III colon cancer. However, completing the full-cycle of oxaliplatin is often associated with severe neurotoxicity. To spare patients from the toxic effects, without comprising the required efficacy, we evaluated the safety and efficacy of a modified XELOX (mXELOX) adjuvant chemotherapy regimen with 6 cycles of oxaliplatin and a full cycle of capecitabine. Methods We retrospectively analyzed 330 eligible patients with stage III colon cancer who underwent curative tumor resection followed by mXELOX, standard XELOX or unfinished XELOX adjuvant chemotherapy between December 2007 and April 2015. Associated prognostic factors were investigated and their disease-free survival (DFS) and overall survival (OS) rates were also determined and compared among the different regimen groups. Results Compared with the standard XELOX group, the mXELOX group had lower total incidence rates of neurotoxicity (39.3% vs. 76.2%, P < 0.001), leucopenia (53.6% vs. 69.8%, P = 0.017) and thrombocytopenia (38.1% vs. 56.3%, P = 0.011). The standard XELOX and mXELOX adjuvant chemotherapy regimens presented with comparable 3-year DFS rates (86.3% vs. 89.2%; P = 0.838) and 3-year OS rates (92.7% vs. 97.6%; P = 0.227). Compared to unfinished XELOX chemotherapy, the oncologic benefits of the mXELOX regimen were greater for patients with T4 tumors (3-year DFS: Hazard ratio [HR], 2.184; 95% confidence interval [CI], 1.051-4.540; P = 0.036; 3-year OS: HR, 4.529; 95% CI 1.245-16.479; P = 0.022) and for high-risk patients (3-year DFS: HR, 1.962; 95% CI 0.964-3.993; P = 0.044; 3-year OS: HR, 4.193; 95% CI 1.182-14.874; P = 0.026). Conclusions The mXELOX adjuvant chemotherapy presented a comparable survival benefit and lower incidence of toxicity than standard XELOX chemotherapy. It could be an alternative treatment for high-risk patients with operated stage III colon cancer.