A Phase II Study of Local Excision Alone or Local Excision Plus Adjuvant Chemoradiation Therapy for Small Distal Rectal Cancers

Age >= 18 years; CTC performance status 0-2; non-pregnant; non-nursing; adenocarcinoma of the rectum (T1 or T2 by physical and endoscopic exam); tumor < 4 cm at greatest diameter and involve < 40% of rectal wall circumference; proximal margin of tumor must be <= 8 cm from the dentate line; patients with villous adenomas or in situ carcinoma are eligible without biopsy proven cancer provided they clinically appear like cancer; patients referred after incomplete colonoscopic removal of tumor are eligible; patients with tumor fixation to the perirectal tissues are not eligible; patients with multi-focal disease within the rectum at time of initial presentation are not eligible; patients with clinical or radiographic imaging evidence of malignant regional lymph node or distant metastases are not eligible; patients with palpable perirectal lymph nodes or nodes larger than 1 cm on preoperative imaging are not eligible; patients with evidence of malignant perirectal lymph nodes by preoperative endorectal ultrasound or endorectal MRI are not eligible; patients must undergo a full thickness disc excision; no prior or concurrent malignancy other than inactive non-melanomatous skin cancer, in-situ carcinoma of the cervix, or other cancer from which patient has been disease free for >= 5 years; no prior radiation therapy, chemotherapy or local rectal excision treatment; WBC >= 4,000; platelets >= 100,000; bilirubin < 1.5 x normal; creatinine < 1.8 mg/dl. To be eligible for second registration, the following must be met following surgery: must have undergone a full thickness excision of tumor with negative surgical margins; must be T1/T2, N0 or NX, M0 or MX.