Neoadjuvant capecitabine and oxaliplatin followed by synchronous chemoradiation and total mesorectal excision in magnetic resonance imaging-defined poor-risk rectal cancer.

PURPOSE: To evaluate neoadjuvant capecitabine/oxaliplatin before chemoradiotherapy (CRT) and total mesorectal excision (TME) in newly diagnosed patients with magnetic resonance imaging (MRI) -defined poor-risk rectal cancer. PATIENTS AND METHODS: MRI criteria for poor-risk rectal cancer were tumors within 1 mm of mesorectal fascia (ie, circumferential resection margin threatened), T3 tumors at or below levators, tumors extending > or = 5 mm into perirectal fat, T4 tumors, and T1-4N2 tumors. Patients received 12 weeks of neoadjuvant capecitabine/oxaliplatin followed by concomitant capecitabine and radiotherapy. TME was planned 6 weeks after CRT. Postoperatively, patients received another 12 weeks of capecitabine.
RESULTS: Between November 2001 and August 2004, 77 eligible patients were recruited. After neoadjuvant capecitabine/oxaliplatin, the radiologic response rate was 88%. In addition, 86% of patients had symptomatic responses in a median of 32 days (ie, just over one cycle of capecitabine/oxaliplatin). After CRT, the tumor response rate was increased to 97%. Three patients remained inoperable. Sixty-seven patients proceeded to TME, and all but one patient had R0 resection. Pathologic complete response was observed in 16 patients (24%; 95% CI, 14% to 36%), and in an additional 32 patients (48%), only microscopic tumor foci were found on surgical specimens. Four deaths occurred during neoadjuvant capecitabine/oxaliplatin therapy as a result of pulmonary embolism, ischemic heart disease, sudden death with history of chest pain, and neutropenic colitis.
CONCLUSION: Capecitabine/oxaliplatin before synchronous CRT and TME results in substantial tumor regression, rapid symptomatic response, and achievement of R0 resection.