Preoperative radiotherapy improves survival in rectal signet-ring cell carcinoma-a population-based study

BACKGROUND: To investigate the clinical value of preoperative and postoperative radiotherapy (RT) in patients with rectal signet-ring cell carcinoma (SRCC). METHODS: Using the Surveillance, Epidemiology, and End Results program patients with stage II–III rectal SRCC were retrospectively included between 1988 and 2012. Univariate and multivariate Cox regression analyses were performed to analyze the effect of preoperative and postoperative RT on cause-specific survival (CSS). RESULTS: A total of 292 patients were included: 138 patients received preoperative RT, 101 patients received postoperative RT, and 53 patients underwent surgery alone. Overall, 5– and 10-year CSS was 43.8 and 37.6%, respectively. Preliminary survival analysis demonstrated that preoperative RT improved CSS versus surgery alone, especially in patients with stage III disease. Multivariate analysis demonstrated that preoperative RT was independent predictors for CSS in stage III rectal SRCC. CSS in preoperative and postoperative RT groups was comparable. CONCLUSIONS: Preoperative RT significantly improved survival outcomes in patients with stage III rectal SRCC.