Neoadjuvant capecitabine and oxaliplatin (XELOX) with bevacizumab for locally advanced rectal cancer.

Abstract

566 Background: Chemoradiotherapy (CRT) followed by surgery is a standard treatment for locally advanced rectal cancer. Although preoperative CRT decreases local recurrence (LR), pelvic radiation is associated with long-term morbidity. We conducted this study to evaluate the feasibility of neoadjuvant XELOX with bevacizumab (Bmab) in patients (pts) with locally advanced rectal cancer. Methods: Pts with T4 or lymph node (LN) positive rectal cancer were treated with 3 cycles of XELOX with Bmab and one additional cycle of XELOX. Total mesorectal excision was performed 3-8 weeks after the last chemotherapy. The primary endpoint was to assess feasibility and secondary endpoints were R0 resection rate, down staging rate, pathological complete response (pCR) rate and pathological effect over grade 2 (tumor cell death in more than two-thirds of the entire lesion). Results: Twenty five pts were recruited between December 2009 and November 2011. Characteristics of pts were as the following: male/female, 18/7; median age, 63 years (range, 37-75); median diameter of tumor, 52.8mm (range, 38.3-110); T2-T3/T4a/T4b, 7/8/10 and N0/N1/N2, 3/14/8. In 4% of the pts (7 pts), following grade 3-4 adverse events occurred; neutropenia, hypertension, bleeding, rectal obstruction, pelvic infection, anorexia and nausea. The down staging rate of T2-T3/T4a/T4b and N1/N2 were 29/63/50 % and 86/63 %, respectively. Seven pts (28%) discontinued the treatment after 2-3 cycles of XELOX with Bmab (13% in T2-T4a, 50% in T4b). The rate of conducting surgery was 92% and all of them had R0 resections. Postoperative complications were found in 9 pts (39%). The pCR rate was 4%, and the rate of pathological effect over grade 2 was 61%. Two LR (LN positive) and two distant recurrences (1 lung, 1 liver) were reported. Conclusions: XELOX with Bmab followed by surgery was safely performed for locally advanced rectal cancer. The down staging rate was 50% even in T4b pts although half of T4b pts discontinued the study treatment. Based on these preliminary results, we are planning a phase II trial of perioperative XELOX and surgery in locally advanced rectal cancer. Clinical trial information: 000003219.