Prognostic factors in patients with locally advanced rectal adenocarcinoma treated with preoperative radiotherapy and surgery.

Preoperative radiation therapy (PRT) prior to potential curative resection for rectal adenocarcinoma is not widely accepted. This report evaluates the prognostic factors affecting local recurrence and 5-year survival. This is a retrospective study of 214 patients with primary rectal adenocarcinoma treated from January 1986 to December 1994. A PRT dosage of 45 Gy in 20 fractions was administered to patients with clinically tethered or fixed tumors, and 4 to 8 weeks later surgery was performed (group I). Patients with clinically mobile tumors were treated by surgery alone (group II). There were 130 men and 84 women. The median age was 58 years (range 19-85 years). There were 111 patients in group I: 7 patients had no microscopic residual tumor, 80 had Dukes' A and B, and 24 had Dukes' C. There were 103 patients in group II: 70 patients were classified as Dukes' A and B and 33 as Dukes' C. The mean follow-up of the entire cohort was 62 months (range 2-132 months). Local recurrence was seen in 17% of patients in group I and 35% in group II (p = 0.002). Distant recurrence in patients with metastatic lymph nodes was seen in 79% of group I and in 34% of group II (p = 0.001). The favorable prognostic factors for local control were the administration of PRT and well differentiated cancer. The favorable prognostic factors for survival were age < 50 years and the absence of lymph node metastasis. The administration of PRT diminishes the risk of local recurrence. The presence of metastatic lymph nodes in the postirradiated specimen is an ominous prognostic factor for survival. Therefore such patients should be considered for adjuvant chemotherapy.