Cisplatin- vs. oxaliplatin-based radiosensitizing chemotherapy for squamous cell carcinoma of the esophagus A comparison of two preoperative radiochemotherapy regimens

Purpose. To compare the outcomes of two neoadjuvant radiochemotherapy (N-RCT) regimens for squamous cell carcinoma of the esophagus (ESCC). Methods. The standard N-RCT regimen for ESCC at our institution between 2002 and 2011 was a total dose of 45 Gy (1.8-Gy fractions) with concomitant cisplatin (20 mg/m(2), days 1-5 and 29-33) and 5-fluorouracil (5-FU; 225 mg/m(2), 24 h continuous infusion on days 1-33). During the same period, a phase I/II study comparing the standard ESCC N-RCT protocol with a regimen identical except for the replacement of cisplatin with weekly oxaliplatin (40-50 mg/m(2)) was performed at our center. The standard regimen was used to treat 40 patients; 37 received the oxaliplatin regimen. All patients subsequently underwent radical resection with reconstruction according to tumor location and two-field lymph node dissection. Results. Median follow-up time from the start of N-RCT was 74 months (range 3-116 months). The two patient groups were comparable in terms of demographic and baseline tumor characteristics. R0 resection was achieved in 37/39 patients (95%) in the cisplatin-based N-RCT group, compared to 24/37 (65%) in the oxaliplatin-based group (p = 0.002). A pathological complete response (pCR) was seen in the resection specimens from 18/39 patients (46%) in the cisplatin-based N-RCT group and in 8/37 (22%) oxaliplatin-group patients. In the cisplatin group, 2- and 5-year overall survival (OS) rates were 67 +/- 8% and 60 +/- 8%, respectively (median OS 103 months), compared to 38 +/- 8% and 32 +/- 8%, respectively, for the oxaliplatin group (median OS 17 months; hazard ratio, HR 0.452; 95% confidence interval, CI 0.244-0.839; p = 0.012). Conclusion. Oxaliplatin-based N-RCT resulted in poorer outcomes in ESCC patients and should not routinely replace cisplatin-based N-RCT.