Efficacy of Preoperative Radiation Therapy for Resectable Rectal Adenocarcinoma When Combined With Oral Tegafur-Uracil Modulated With Leucovorin

PURPOSE: The aim of this study was to evaluate the efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma (T3-T4) when delivered in combination with chemotherapy (oral tegafur-uracil modulated with leucovorin). METHODS: Thirty-eight patients (23 males; mean age, 62 years.) with histologically proven rectal adenocarcinoma with primary tumor clinical classification T3-T4 (resectable) and N0 or N1-N2, according to TNM staging system, took part in the present clinical trial. After tumor and metastasis resectability confirmation, radiation therapy was administered by delivering a dose of 45 Gy in 25 fractions for 5 weeks. Chemotherapy treatment was initiated on the same day as radiotherapy and consisted of intravenous infusion of 6S-steroisomer of leucovorin 250 mg/m2/day in 2 hours on Day 1, followed by oral 350 or 300 mg/m2/day of tegafur (a 5-fluorouracil prodrug) plus uracil on Days 1 to 14 divided into 2 daily doses, and oral 6S-steroisomer of leucovorin 7.5 mg/12 hours on Days 2 to 14, with a total of 102 courses of neoadjuvant chemotherapy (i.e., mean of 2.7 courses per patient). Six additional courses of tegafur-uracil were given postoperatively to all 38 patients but 1 who refused. RESULTS: As a result of preoperative chemoradiation treatment, 4 (10.5 percent) complete responses, 20 (52.6 percent) partial responses, and 14 (36.8 percent) patients with disease stabilization were observed. No patients had preoperative disease progression. Histologically proven downstaging was observed in 23 (60 percent) patients. On initial evaluation, only 39 percent of patients were considered as being good candidates for sphincter-preserving surgery; however, on preoperative chemoradiation completion this figure increased up to 60 percent. For the 23 patients eventually undergoing sphincter-preserving surgery, postoperative sphincter function assessment showed excellent function in 15 (65 percent) patients, good in 5 (22 percent), fair in 2 (9 percent), and poor in 1(4 percent). With a median follow-up of 37 (range, 10–62) months, local failure was found in 3 (8 percent) patients and distant failure in 2 (5 percent). Three-year actuarial disease-free survival and 3-year overall survival rates were 83 and 90 percent, respectively. Local control rate was 92 percent. Toxicity and postoperative complication rates were reasonable. CONCLUSIONS: Our neoadjuvant radiation therapy protocol is efficient for the preoperative treatment of resectable rectal adenocarcinoma when combined with chemotherapy (oral tegafur-uracil modulated with leucovorin). However, this protocol needs to be tested in a phase-III clinical trial with a larger sample size.