e14117 Background: Achieving complete pathological response (CPR) with neoadjuvant chemoradiation may predict a higher likelihood of long-term survival in patients with operable rectal cancer. However, studies done with single agent 5-FU based regimen have yielded conflicting data. This may be due to the inherent low activity of 5-FU in treating micrometastatic diseases. In animal models, celecoxib has been shown to increase cytotoxic effects of radiation while exerts protective effects to normal skin. We therefore conducted a phase II trial using combination of oxaliplatin, capecitabine and celecoxib concurrent with radiation in patients with operable rectal cancer. Methods: Twenty-one patients are enrolled in this single-arm phase II trial of neoadjuvant chemoradiation for patients with T3-4N0-2M0 rectal cancer from March 2006 to July 2009. Age range is 30-71 and eight are female. Pretreatment staging are assessed by colonoscopy, endoscopic ultrasound, and CT or PET/CT. Chemoradiation regimen consists of a total dose of 45 Gy radiation therapy in 25 fractions from Monday to Friday over 5 weeks. Oxaliplatin 50 mg/m2/weekly and capecitabine 850 mg/m2/bid are given five days a week with radiation therapy. Celebrex 200 mg bid are given throughout the duration of radiation without a break. Results: Seventeen out of twenty-one patients completed the treatment. Six patients (35.3%) had CPR, four (25.3%) had near complete pathological response (NCPR) and seven (41.1%) had residual disease (RD). The median survival has not been reached for the whole treatment group with a median follow-up of 24 (range 6-42) months. None of the patients with CPR had disease progression with follow-up range from 6-42 months. Grade 2-3 nausea, vomiting and diarrhea were the most common side effects. However, two patients had grade 4 symptoms that required hospitalization and subsequently developed fatal arrhythmia and sepsis. Conclusions: This regimen is effective in inducing a very high rate of CPR in patients with locally advanced resectable colon cancer. This phase II trial is ongoing and anticipate completion in 2010. No significant financial relationships to disclose.
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