Postoperative Adjuvant Chemoradiotherapy in Rectal Cancer / 대한방사선종양학회지

ABSTRACT

PURPOSE: To evaluate the role of postoperative adjuvant chemoradiotherapy in rectal cancer, we retrospectively analyzed the treatment outcome of patients with rectal cancer taken curative surgical resection and postoperative adjuvant chemoradiotherapy. MATERIALS AND METHODS: A total 46 patients with AJCC stage II and III carcinoma of rectum were treated with curative surgical resection and postoperative adjuvant chemoradiotherapy. T3 and T4 stage were 38 and 8 patients, respectively. N0, N1, and N2 stage were 12, 16, 18 patients, respectively. Forty patients received bolus infusions of 5-fluorouracil (500 mg/m2/day) with leucovorin (20 mg/m2/day), every 4 weeks interval for 6 cycles. Oral Uracil/Tegafur on a daily basis for 6~12 months was given in 6 patients. Radiotherapy with 45 Gy was delivered to the surgical bed and regional pelvic lymph node area, followed by 5.4~9 Gy boost to the surgical bed. The follow up period ranged from 8 to 75 months with a median 35 months. RESULTS: Treatment failure occurred in 17 patients (37%). Locoregional failure occurred in 4 patients (8.7%) and distant failure in 16 patients (34.8%). There was no local failure only. Five year actuarial overall survival (OS) was 51.5% and relapse free survival (RFS) was 58.7%. The OS and RFS were 100%, 100% in stage N0 patients, 53.7%, 47.6% in N1 patients, and 0%, 41.2% in N2 patients (p=0.012, p=0.009). The RFS was 55%, 78.5%, and 31.2% in upper, middle, and lower rectal cancer patients, respectively (p=0.006). Multivariate analysis showed that N stage (p=0.012) was significant prognostic factor for OS and that N stage (p=0.001) and location of tumor (p=0.006) were for RFS. Bowel complications requiring surgery occurred in 3 patients. CONCLUSION: Postoperative adjuvant chemoradiotherapy was an effective modality for locoregional control of rectal cancer. But further investigations for reducing the distant failure rate are necessary because distant failure rate is still high.