Lymph node yield in colorectal cancer specimens and its impact on pathological staging: Does number matter?

• Published in: Journal of cancer research and therapeutics Vol. 19; no. 3; pp. 671 - 674
• Main Authors: Mounika, R, Ananthamurthy, Anuradha
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.07.2023; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd
• Subjects: Care and treatment; Colorectal cancer; Diagnosis; Health aspects; Lymph nodes; Lymphatic system; India; pathological staging; lymph node yield; Colorectal cancer
• ISSN: 0973-1482; 1998-4138
• DOI: 10.4103/jcrt.jcrt_980_21

Introduction: Regional lymph node involvement is an important predictor of outcome in colorectal cancer (CRC). The lymph node yield in resected specimens varies from case to case. Aim: To assess whether clinicopathologic factors have an impact on the number of lymph nodes harvested from surgical resection specimens of CRCsTo assess whether the total number of lymph nodes retrieved has a bearing on the positivity of lymph nodes and hence the N category. Materials and Methods: All resection specimens of treatment naïve CRC received in the department of pathology during a 2 year period (2017-2019) were reviewed. The lymph node yield was correlated with age, sex, type of surgical procedure, length of resected segment, tumor location, histological type and grade, T and N categories. The statistical tests used were Spearman rank, Mann-Whitney U, Kruskal-Wallis, and Chi-square tests. Results: A total of 51 resections were studied. The mean age was 59.64 years with 72.55% being male. About 76.47% were hemicolectomies and 23.52% were rectosigmoid surgeries. The lymph node yield ranged from 0 to 38, the mean being 12.67. None of the parameters studied had a significant correlation with the lymph node yield except histological grade, specimens with higher-grade tumors yielding more number of nodes (P = 0.0242). There was no significant correlation between node positivity and the average number of lymph nodes (P = 0.0883). There was no significant correlation between total yield in cases with ≥12 lymph nodes and N category (P = 0.180). Furthermore, there was no significant correlation between total yield in node-positive cases with ≥12 lymph nodes and N category (P = 0.216). There was no significant difference in the sizes of the lymph nodes in node-positive and negative cases (P = 0.3930 and 0.2355, respectively). Conclusion: Among the parameters affecting lymph node yield, the current study found a significant correlation between histological grade and lymph node yield. There was no significant difference in the size of lymph nodes between node-positive and negative cases. The total lymph node yield did not have a bearing on node positivity and this shows that a lower lymph node yield may be accepted as adequate after thorough examination of the specimen.