Comparison of treatment results between surgery alone, preoperative short-course radiotherapy, or long-course concurrent chemoradiotherapy in locally advanced rectal cancer

Background: The aim of this study is to compare the results between surgery alone, preoperative radiotherapy (RT), or preoperative concurrent chemoradiotherapy (CCRT) followed by surgery in the treatment of locally advanced rectal cancer in Asian patients. Methods: This study included 151 consecutive patients with clinical T3, T4 or node-positive rectal cancer from Jan. 2005 to Dec. 2007. Eighty-six patients underwent total mesorectal excision (TME) alone, 28 patients received preoperative RT (25 Gy in 5 fractions) followed by TME in 1 week, and 37 patients received preoperative CCRT (50.4 Gy in 28 fractions) followed by TME in 4-6 weeks. Results: The 3-year loco-regional recurrence (LRR), distant metastasis, overall and disease-free survival rates are comparable among Surgery, RT and CCRT groups. By multivariate analysis, pT4, distal margin <2 cm, the ratio of positive lymph nodes to totally dissected lymph nodes ≥0.2, and non-R0 resection were significant factors for LRR. In subgroup analysis, TME alone produced comparable LRR to RT or CCRT (3.3 vs.. 4.8%) for favorable patients (0-1 risk factors). For unfavorable patients (2 or more risk factors), the LRR rose to 37% in patients receiving surgery alone as compared with 15% in the RT or CCRT patients. Conclusions: Preoperative RT or CCRT followed by TME produced good local control in favorable and unfavorable patients with locally advanced rectal cancer. If preoperative RT or CCRT is not given, TME alone has a high incidence of local recurrence in unfavorable patients with 2 or more risk factors.