Aim Retrieval of a minimum of 12 lymph nodes has been recommended for adequately staging a node-negative colorectal cancer (CRC). This study was designed to determine whether the extra effort expended to recover more nodes for histological examination improves the accuracy of staging. Method Pathology reports, histology worklists, and haematoxylin and eosin (H&E) slides of 334 CRC resections were reviewed. The total number of nodes and the number of positive nodes harvested from the first and additional searches were recorded for each patient. Results The number of nodes retrieved from the 334 resections at the first search ranged from 0 to 57 (mean: 14.2), with 195 patients (58.4%) having ≥12 nodes. Nodal metastasis was found in 122 (33.6%) patients. Additional searches were performed on 115 patients, including 91 with <12 nodes. The mean number of nodes recovered in these patients increased significantly, from 9.1 to 14.2 (P<0.0001). Thirty-one additional positive nodes were found in 19 patients following the further searches, and 12 (63.2%) of the 19 patients were upstaged using the American Joint Committee on Cancer (AJCC) 6th edition (2002) staging criteria. The total number of nodes retrieved and the probability of obtaining ≥12 nodes correlated negatively with the age of the patient and the rectosigmoid location of the tumours, but positively with the specimen length, the pericolic/perirectal fat width, female gender and tumour size. Conclusion Although a number of patient and specimen variables influence the number of lymph nodes retrieved, our observations support the importance of a thorough search for nodes in CRC specimens in order to achieve accurate tumour staging. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.
