Lymph node yield in rectal cancer surgery: Effect of preoperative chemoradiotherapy

AimAdequate lymph node resection in rectal cancer is important for staging and local control. This study aims to verify the effect of neoadjuvant chemoradiation, as well as some clinicopathological features, on the yield of lymph nodes in rectal carcinoma.MethodsData on consecutive patients who had total mesorectal excision for rectal adenocarcinoma at a single cancer center between January 2003 and July 2008 were reviewed. No patient had any prior pelvic surgery or radiotherapy. Patients had neoadjuvant chemoradiotherapy if they were stage II or III.ResultsA total of 116 patients were included. The mean age was 53 years (range 29–83). Fifty-nine patients (51%) received neoadjuvant therapy before resection. The mean number of lymph nodes removed was 18 (range 4–67) per specimen. There was less lymph node yield in patients who received neoadjuvant therapy (16 vs. 19, p = 0.008). Only 64% of patients who had preoperative therapy had 12 lymph nodes or more in the specimen as opposed to 88% of those who had surgery upfront (p = 0.003). Other factors associated with lower lymph node yield included: female sex (p = 0.03) and tumour location in the lower rectum (p = 0.002). Age, tumour stage and grade, type of operation and surgical delay did not affect the number of lymph nodes removed.ConclusionPreoperative chemoradiotherapy for rectal cancer results in reduction in lymph node yield. Female sex and lower rectal tumours are also associated with retrieval of fewer lymph nodes.