Advantage of Oxaliplatin-Based Neoadjuvant Concurrent Chemo-Radiotherapy in Treating Locally Advanced Lower Rectal Cancer

Abstract

Background. Complete resection and postoperative treatment for lower advanced rectal cancer is problematic. Clearance of the tumor lesion presents a considerable challenge due to the difficult approachability, and thus the postoperative recurrence of the disease is relatively high. Neoadjuvant concurrent chemo-radiotherapy (CCRT), first described in 1990’s, results in local control with a high percentage of R0 resection and pathologic response rate with comparable results in our previous study. We compared Oxaliplatin-based CCRT with 5-FU alone CCRT and found the improved disease-free and overall survival in patients with stage III rectal cancer. However, the duration of follow-up was short and the study population was small so in the current study we extended our previous research by collecting more patients' data, including a previous CCRT trial, and evaluated the advantages of Oxaliplatin-based CCRT versus the 5-FU CCRT over a one-year period.Methods. From January 2004 to December 2009, (including our previous Oxlipaltin CCRT trial from January 2008 to December 2009, 19 cases), 24 patients with locally advanced lower rectal cancer receiving Oxaliplatin-based neoadjuvant CCRT were enrolled for study group. From January 2005 to December 2009, 72 patients with locally advanced rectal cancer receiving 5-FU alone neoadjuvant CCRT were enrolled and comprised the control group. Factors including circumferential margin and pathologic response rate were evaluated.Results. In the study group, the pathologic response rate was 95.6%, complete response rate was 39.1% and partial response rate was 56.5%. The Oxaliplatin group had a better pathologic response rate versus the 5-FU alone group (95.6% vs. 84.2%, p ＜ 0.0001) with far superior results in complete pathologic response (39.1% vs. 7.0%) and a slightly improved circumferential margin rate (R0 resection 95.7% vs. 91.1%, p = 0.857). The Oxaliplatin group had better sphincter-saving ratio (91.7% vs. 68.1%, p = 0.044) and shorter stays (10.2±4.9 vs.12.9±9.0, p = 0.028). The study group had a tendency of lower local recurrence rate (0% vs. 3%, p =0.154) and a higher survival than the control group (100% vs. 92%, p =0.395) at the 24th month, although no statistically significance is available at the follow up timing.Conclusion. Oxaliplatin-based neoadjuvant CCRT gives locally advanced lower rectal cancer patients more favorable results including higher tumor regression ratio, higher chance of sphincter-saving, shorter hospital stay without increasing complications.