Capecitabine, Oxaliplatin, and Radiation Therapy in Treating Patients Who Are Undergoing Surgery for Stage I Rectal Cancer

OBJECTIVES: Primary * Determine the 3-year disease-free survival rate in patients with stage I adenocarcinoma of the rectum treated with neoadjuvant chemoradiotherapy comprising capecitabine, oxaliplatin, and radiotherapy followed by local excision. Secondary * Determine the rate of resectability with negative resection margins in patients treated with this regimen. * Determine the procedure-specific morbidity and mortality in patients treated with this regimen. * Determine the rate of pathologic complete response of the primary tumor in patients treated with this regimen. * Determine the impact of this regimen on anorectal function and quality of life in these patients. * Determine the feasibility of using molecular studies to assess surgical resection margins and tumor response in patients treated with this regimen. * Determine molecular markers associated with local tumor recurrence in patients treated with this regimen. OUTLINE: This is a non-randomized, multicenter study. Patients undergo high-dose external beam radiotherapy once daily on days 1-5, 8-12, 15-19, 22-26, and 29-33. Patients also receive oral capecitabine twice daily on days 1-14 and 22-35 and oxaliplatin IV over 2 hours on days 1, 8, 22, and 29. Approximately 4-8 weeks after completion of chemoradiotherapy, patients undergo local excision of the tumor. Patients with T3 disease or positive resection margins after local excision undergo radical resection of the rectum and receive additional chemotherapy and/or radiotherapy at the discretion of the physician. Quality of life is assessed at baseline and then 1 year after surgery. After completion of study treatment, patients are followed at 1 month, every 4 months for 3 years, and then every 6 months for 2 years. PROJECTED ACCRUAL: A total of 102 patients will be accrued for this study within 2.8 years.