Preoperative Chemoradiotherapy of Locally Advanced Rectal Cancer: Preliminary Results of BID Fractionation
INTRODUCTION: Preoperative chemoradiotherapy is an effective modality for patients with locally advanced rectal cancer. This study was designed to evaluate the efficacy, tolerance, and toxicity of preoperative chemoradiotherapy (CRT) using BID fractionation in patients with locally advanced rectal cancer. PATIENTS AND METHODS: Between January 2001 and November 2007, 35 patients were treated with preoperative CRT, and then received operation due to locally advanced rectal cancer. Three cycle of chemotherapy were delivered with 5-FU based regimen, mainly FOLFIRI (n=25), every 3 weeks. Radiation treatment scheme was 1.5 Gy (n=31) or 1.6 Gy (n=4) of radiation twice a day, and 1st course of radiotherapy of 21-24 Gy was combined concurrently with 1st cycle of chemotherapy followed by 10-12 days rest period and 2nd course of radiotherapy of 21-24Gy was combined concurrently with 2nd cycle of chemotherapy. RESULTS: The median follow up period were 19 months (5-36 months). All were T3 (n=25) or T4 (n=10) and the largest diameter of tumor mass were median 5cm (2.5-14cm). Overall downstaging rate was 71%. Pathologic CR rate was 11% (n=4), near CR (microscopically focal residual tumor, less than 10% of viable cells) with 23% (n=8), PR with 60% (n=21). Two patients were found to have unresectable tumor upon operation. Sphincter-preserving procedure was performed in 43% of 30 patients with the lower rectal cancer. Seven patients (20%) had treatment interruption (1-7 days) as following reasons; 3 for perineal reaction, 1 for neutropenia, and 3 for other problems. Only 8 patients (23%) showed severe acute toxicity (grade 3 neutropenia in 4 patients, grade 3 perineal skin reaction in 3 patients, and grade 3 proctitis in 1 patient). Late toxicity was observed in 2 patients; perineal open wound in one patients and rectovaginal fistula in the other patient. CONCLUSION: Preoperative BID fractionated CRT for locally advanced rectal cancer achieved 34% of pCR or near CR rate. And this treatment regimen as preoperative treatment was feasible without compromising tumor response and with better tolerance in locally advanced rectal cancer.
rectal cancer, neoadjuvant, concurrent chemoradiotherapy, BID-fractionation
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