Preoperative conventional chemoradiotherapy versus short-course radiotherapy with delayed surgery for rectal cancer: results of a randomized controlled trial

BACKGROUND: There still is no evidence which neoadjuvant therapy regimen for stage II–III rectal cancer is superior. The aim of this study was to compare results achieved after long-course chemoradiotherapy (CRT) with short-term radiotherapy (RT) followed by delayed surgery. METHODS: A randomized trial was carried out between 2007–2013. One hundred fifty patients diagnosed with stage II–III rectal cancer were randomized into one of two neoadjuvant treatment arms: conventional chemoradiotherapy (CRT) and short-term radiotherapy (RT) followed by surgery after 6–8 weeks. Primary endpoints of this trial were downstaging and pathological complete response rate. Secondary endpoints were local recurrence rate and overall survival. RESULTS: The pathological complete response was found in 3 (4.4%) cases after RT and 8 (11.1%) after CRT (P = 0.112). Downstaging (stage 0 and I) was observed in 21 (30.9%) cases in RT group vs. 27 (37.5%) cases in CRT group (P = 0.409). Median follow-up time was 39.7 (range 4.9–79.7) months. 3-years overall survival (OS) was 78% in RT group vs. 82.4% in CRT group (P = 0.145), while disease-free survival (DFS) differed significantly – 59% in RT group vs. 75.1% in CRT group (P = 0,022). Hazard ratio of cancer progression for RT patients was 1.93 (95% CI: 1.08–3.43) compared to CRT patients. CONCLUSION: Three-years disease-free survival was better in CRT group comparing with RT group with no difference in overall survival. TRIAL REGISTRATION: http://clinicaltrials.gov identifier NCT00597311. January 2008.