Background: This prospective study assessed the effect of preoperative radiation and chemotherapy on the pathologic staging of advanced rectal cancer.
Methods: Twenty patients with rectal cancer were treated with combined chemoradiation prior to operation, after pretreatment staging of all lesions with transrectal ultrasound (TRUS). Perirectal fat invasion served as minimal criteria for preoperative neoadjuvant therapy. 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 (45 to 54 Gy) in 19 of 20 patients. One patient received in excess of 60 Gy because of tumor characteristics. Chemotherapy consisted of 5-fluorouracil 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 performed.
Results: Following resection, rectal cancer was downstaged in 14 of 20 patients. No tumor was present in the rectal wall in 8 of 20 patients. Complete pathological response was present in 7 of 20 patients. Local recurrence occurred in 2 of 20 patients. Disease-free survival in the remaining 17 of 20 patients ranges from 9 to 51 months (average 26).
Conclusions: Preoperative chemoradiation in the surgical management of advanced rectal cancer results in demonstrable tumor downstaging.