Neoadjuvant treatment of mid-to-lower rectal cancer with oxaliplatin plus 5-fluorouracil and leucovorin in combination with radiotherapy: a Korean single center phase II study.

purposeTo evaluate the safety and efficacy of neoadjuvant chemoradiation with oxaliplatin and 5-fluorouracil (5-FU) in advanced mid-to-lower rectal cancer.

methodsThis was a single-arm, open-label phase II study conducted between August 2008 and August 2010. Thirty-one patients (n = 31) with clinical stage T3/T4 or lymph node positive rectal adenocarcinoma located in the middle or lower rectum without metastasis were enrolled onto the study. Data were analyzed according to the intention-to-treat principle.

resultsThirty-one patients were enrolled into the study. Six patients (19.4%) experienced grade 3 diarrhea. Grade 2 nausea and vomiting occurred in 5 and 2 patients, respectively. Severe neurotoxicity was not observed. Grade 1 sensory neuropathy occurred in 10 patients (32.3%). Sphincter-saving surgery was performed in 29 patients (93.5%). The mean distance of the tumor from the anal verge was 4.9 cm. Anastomotic leakage occurred in 4 of 29 (13.8%) patients. The circumferential resection margin was involved in 2 patients (6.5%). Overall, 23 patients (77.4%) responded to treatment. The complete pathologic response (ypCR) rate was 12.9%. There was no death secondary to toxicity, and the mean follow-up time was 12.3 months.

conclusionThe overall toxicity of oxaliplatin and continuous 5-FU/leucovorin infusion in combination with radiation was well tolerated. Neoadjuvant chemoradiation for patients with locally advanced rectal cancer was associated with higher rates of sphincter preservation and downstaging, but did not significantly increase ypCR. The impact of this neoadjuvant chemoradiation regimen on survival will be determined by longer follow-up studies.