Evaluation of Preoperative Chemotherapy with Modified OPTIMOX-1 Plus Bevacizumab in Patients with Advanced Rectal Cancer with Factors Contraindicative of Curative Surgery.

BACKGROUND/AIMS: The efficacy and safety of neoadjuvant chemotherapy in patients with highly advanced rectal cancer for whom radical surgery was considered difficult were evaluated.

METHODOLOGY: From June 2007 to February 2011, 10 advanced lower rectal cancer patients with factors contraindicative of curative surgery with total mesenteric excision were eligible for this study. Neoadjuvant chemotherapy consisting of modified OPTIMOX1 (mFOLFOX6 and sLV5FU2 alternating administration) plus bevacizumab was administered.

RESULTS: Adverse events seen with chemotherapy consisted of grade 2 leukopenia in 1 patient, but there were no cases of delayed administration or dosage reduction due to grade 2 neurotoxicity. The surgical procedures were anus-preserving resection in 8 patients, total pelvic exenteration in 1 patient, and posterior pelvic exenteration in 1 patient. A positive radial margin was confirmed in 3 patients, but radical surgery was performed, histologically as well, in the other patients. Upon comparing the clinical and postoperative histological stages, primary tumor and node downstaging was achieved in 20.0% and 70.0% of the patients, respectively.

CONCLUSIONS: These findings suggest the potential utility of neoadjuvant chemotherapy consisting of modified OPTIMOX1 plus bevacizumab prior to permitting radical resection or anus-preserving surgery in patients with highly advanced rectal cancer.