[Efficacy comparison of neoadjuvant radiotherapy with or without chemotherapy for locally advanced rectal cancer]

To evaluate the efficacy of neoadjuvant radiotherapy alone versus chemoradiotherapy in patients with mid-low locally advanced rectal cancer.

Data of 69 patients with advanced (stage T(3) or T(4)) rectal cancer, undergone neoadjuvant therapy in our hospital from October 1997 to October 2007, were analyzed retrospectively. Forty patients received preoperative radiotherapy (50 Gy in 25 fractions over 5 weeks) alone (RT group), and 29 patients received preoperative radiotherapy concomitant with 5-FU/leucovorin -based preoperative chemoradiotherapy (CRT group). Radical surgery was performed 4-6 weeks after radiation therapy by the rule of TME.

All the patients underwent operations, including 26 abdominoperineal resections, 27 anterior resections, 10 Parks operations and 6 Hartmann's procedures. The sphincter preservation rate was 47.5%(19/40) in RT group, and 62.1%(18/29) in CRT group(P>0.05). In pathological findings, tumor and nodal downstaging were observed in 12 patients of RT group (30.0%), and 17 of CRT group (58.6%)(P<0.05). In RT group, 3 patients (7.5%) showed pathological complete regression (pCR), and the overall response rate (CR plus PR) was 60%(24/40). In CRT group, 4(13.8%) showed pCR and the overall response rate was 79.3%(23/29). There was significant difference of the overall response rate between two groups. Three-year disease-free survival for all patients was 77.3%.

For patients with locally advanced rectal cancer, neoadjuvant chemoradiotherapy provides higher sphincter preservation rate, overall response rate and better down-staging as compared to radiotherapy alone.