Preoperative chemoradiotherapy versus surgery alone for advanced low rectal cancer: a large multicenter cohort study in Japan.

PURPOSE To clarify the usefulness of chemoradiotherapy (CRT) for low rectal cancer, we investigated the current status of CRT in Japan and its short- and long-term outcomes versus surgery alone for low rectal cancer in a large multicenter cohort study. METHODS Between January 2010 and December 2011, data from 1608 patients with clinical Stage II-III rectal adenocarcinoma were collected from 69 specialized centers. Of these 1608 patients, 923 were diagnosed with clinical stage III low rectal cancer, 838 were enrolled in this study, divided into the surgery-alone group (n = 649) and preoperative CRT group (n = 189), and analyzed. RESULTS The following parameters were significantly lower in the CRT versus surgery-alone group: blood loss (210 vs. 431.5 mL), postoperative complications (27.5% vs 39.0%), and the incidence of anastomotic leakage (3.7% vs. 8.8%). The 3-year overall survival, relapse-free and local recurrence-free survival rates did not between the two groups to a statistically significant extent (91.2% vs. 87.4%, 68.8% vs. 66.4%, and 88.2% vs. 88.4%, respectively). CONCLUSIONS The present study revealed the current status of CRT for low rectal cancer in Japan. The results showed that CRT could be safely performed for advanced low rectal cancer in comparison to surgery alone.