Neoadjuvant Oxaliplatin and Capecitabine and Bevacizumab without Radiotherapy for Poor-risk Rectal Cancer: N-SOG 03 Phase II Trial

Abstract

Objective: This Phase II trial was designed to evaluate the safety and efficacy of neoadjuvant oxaliplatin and capecitabine and bevacizumab without radiotherapy in patients with poor-risk rectal cancer. Methods: Patients with magnetic resonance imaging-defined poor-risk rectal cancer received neoadjuvant oxaliplatin and capecitabine and bevacizumab followed by total mesorectal excision or more extensive surgery. Results: Between February 2010 and December 2011, 32 patients were enrolled in this study. The completion rate of the scheduled chemotherapy was 91%. Reasons for withdrawal were refusal to continue therapy in two patients and disease progression in one, with two of these three patients not undergoing surgery. Among the 29 patients who completed the scheduled chemotherapy, one refused surgery within 8 weeks after the completion of chemotherapy, which was the period stipulated by the protocol, and another had rectal perforation, requiring urgent laparotomy. As a result, the completion rate of this experimental treatment was 84%. Of the 30 patients who underwent surgery, the R0 resection rate was 90% and a postoperative complication occurred in 43%. A pathological complete response was observed in 13% and good tumor regression was exhibited in 37%. Conclusions: Neoadjuvant oxaliplatin and capecitabine plus bevacizumab for poor-risk rectal cancer caused a high rate of anastomotic leakage and experienced a case with perforation during chemotherapy, both of which were bevacizumab-related toxicity. Although the shortterm results with the completion rate of 84.4% and the pathological complete response rate of 13.3% were satisfactory, we have to reconsider the necessity of bevacizumab in neoadjuvant chemotherapy (UMIN number, 000003507).

Neoadjuvant treatment for locally advanced rectal cancer: a systematic review

“…The preoperative induction of aggressive chemotherapy is anticipated to not only suppress distant metastasis, but to also improve local control in patients with highrisk rectal cancer. The N-SOG03 trial, which evaluated the safety and efficacy of neoadjuvant CAPOX + Bev, showed satisfactory short-term results with a completion rate of 84.4 % and pathological complete response rate of 13.3 % [57]. In this trial, a high rate of Bev-related toxicities, including anastomotic leakage, was a serious problem.…”

“…Recently, several studies have been performed to evaluate the safety and efficacy of NAC alone, both in Western countries and Japan ( Several trials have been conducted in Japan to evaluate the safety and efficacy of NAC alone for the treatment of high-risk rectal cancer [57,58]. Upfront surgery is the standard Japanese treatment.…”

The pivotal role of DNA methylation in the radio‐sensitivity of tumor radiotherapy

“…The sensitization mechanism of 5‐fluorouracil is to inhibit the thymidylate synthetase 7. For platinum, its mechanism includes radiation‐induced free radicals prompting the formation of toxic platinum intermediates, inhibition of DNA repair, radiation‐induced enhancement of cell platinum absorption, and cell cycle arrest 8, 9. Via redistributing tumor cells into S phase and causing the depletion of the deoxy ATP, gemcitabine can enhance the radio‐sensitivity of tumor radiotherapy 10.…”

An elderly patient with marginally unresectable rectal cancer obtained pathological complete response by the treatment with mFOLFOX6

“…Therefore it is often performed with or without molecular targeted drugs for the unresectable or marginally unresectable colorectal cancer to expect that it would be shrunk to be resectable [3][4][5][6] .…”