Treatment Outcome Survey for Stage II/III Rectal Cancer; Korean Multicenter Retrospective Study

초록

(Introduction) The evidence of oncologic benefit for adjuvant therapy after radical resection of rectal cancer is insufficient. This multicenter retrospective study was designed to evaluate the impact of postoperative adjuvant therapy on oncologic outcome in rectal cancer patient who did not receive neoadjuvant therapy. (Method and Materials) A retrospective analysis was made of all patients who underwent radical resection for stage II/III rectal cancer in nine hospitals from January 2004 to December 2009. The patients with preoperative chemotherapy or radiation was excluded in analysis. Study population were categorized into 3 adjuvant group, i.e, surgery group (without any type of adjuvant therapy), chemotherapy group and radiation group. 5-year overall survival (OS) and disease-free survival (DFS) was analyzed with Kaplan-Meier method and independent predictive factors affecting survival was calculated by Cox proportional Hazard Model. (Results) Total 775 patient was included in analysis and median period of follow up was 57 months. The study group was composed of 469 men and 306 female, with a mean (range) age of 63.8 (13~91). Pathologic stage distribution included pStage II in 356 patients (45.9%) and pStage III in 419 (54.1%), and positive rate of circumferential resction margin (CRM) occurred in 83 patients (10.7%). The group of adjuvant therapy was Surgery group (SG) in 56 patient (7.2%), Chemotherapy group (CG) in 460 patients (59.4%) and Radiation group in 259 patient (33.4%). Among the group, there was no significant difference in gender, but the patients of surgery group was significantly older than other group. (SG 69.2 year vs CG 64.5 year vs RG 61.4 year, p=0.000). In radiation group, the tumor was located in more distal rectum (Distance from anal verge: SG 8.4cm vs CG 8.8cm vs RG 7.3%. p=0.000), therefore abdominoperineal resection (APR) was more frequently performed (Proportion of APR: SG 16.1% vs CG 12.4% vs RG 19.3%. P=0.018). Especially, there wa