Number of lymph nodes recovered as an independent prognostic factor in predicting outcome in patients with pathologically node-negative rectal cancer following preoperative chemo/radiotherapy.

606 Background: To determine the importance of number of lymph nodes recovered on outcome in pathological node negative rectal cancer patients who had received chemo/radiotherapy prior to surgery. Methods: We retrospectively analysed data from 262 patients with locally advanced rectal cancer who received pre-operative chemo/radiotherapy at Castle Hill Hospital, Cottingham and Nottingham University Hospital between 2001 and 2008. Patients were treated with CT planned radiotherapy to a dose of 45-50 Gy in 25 fractions with concurrent fluoropyrimidine chemotherapy. Surgery was normally performed at an interval of 6-8 weeks. There were 152 patients who were found to be pathologically node negative for further analysis. Median follow-up was 51.5 months Patients were grouped into 10 nodes recovered. Disease free survival (DFS) and overall survival (OS) was assessed using Log rank test. Multivariate analysis was performed using Cox-regression analysis. Results: Of the 152 patients analy...