PREOPERATIVE CHEMORADIATION DOWNSTAGES LOCALLY ADVANCED ULTRASOUND-STAGE RECTAL-CANCER

BACKGROUND: This prospective study assessed the effect of preoperative radiation and chemotherapy on the pathologic staging of advanced rect al cancer. METHODS: Twenty patients with rectal cancer were treated wi th combined chemoradiation prior to operation, after pretreatment stag ing of all lesions with transrectal ultrasound (TRUS). Perirectal fat invasion served as minimal criteria for preoperative neoadjuvant thera py. The pretreatment stage of these rectal lesions as defined by TRUS was then compared with the pathological stage of the surgical specimen following resection. Cancers were treated with high-dose radiation (4 5 to 54 Gy) in 19 of 20 patients. One patient received in excess of 60 Gy because of turner characteristics. Chemotherapy consisted of 5-flu orouracil delivered as a continuous infusion or bolus therapy. Four to 8 weeks after neoadjuvant therapy, 13 abdominal perineal resections, 5 low anterior resections, and 2 completion proctectomies were perform ed. RESULTS: Following resection, rectal cancer was downstaged in 14 o f 20 patients. No tumor was present in the rectal wall in 8 of 20 pati ents. Complete pathological response was present in 7 of 20 patients. Local recurrence occurred in 2 of 20 patients. Disease-free survival i n the remaining 17 of 20 patients;ranges from 9 to 51 months (average 26). CONCLUSIONS: Preoperative chemoradiation in the surgical manageme nt of advanced rectal cancer results in demonstrable tumor downstaging .