Evaluation of Lymph Nodes Adequacy in Patients with Colorectal Cancer: Results from a Referral Center in Iran

Abstract Background the presence of lymph node metastases is one of the most important prognostic factors for long-term survival of patients with colorectal cancer. So, thorough pathologic examination of at least 12 lymph nodes is essential for accurate staging this disease, as well as choosing the best adjuvant treatment. The aim of this study is to assess the adequacy of lymph node harvest in patients with colorectal cancer. Methods This observational cross-sectional study was performed on 584 patients with colorectal adenocarcinoma who had undergone surgery from 2012 to 2017. Thereafter, the relevant demographic, pathological, and surgical data were extracted from the patients’ medical records and a relationship between the number of evaluated lymph nodes and other variables was also assessed. Results Among 584 studies cases in this study, 336 (57.5%) subjects had less than 12 evaluated lymph nodes. Mean and median number of the evaluated lymph nodes were calculated as 10.7 (± 5.6) and 10, respectively. The patients aged 60 years old and older and the cases with tumors located in descending colon and rectum were observed to have higher chances of inadequate lymph node retrieval. After an average follow-up for a 60-month period, 63% of the patients were alive. In the patients for whom less than 12 lymph nodes had been assessed, the median survival was estimated as 48 months. As well, in the patients for whom the number of the evaluated lymph nodes was ≥ 12, median survival was calculated as 54 months. Conclusion The number of the evaluated lymph nodes in our study was less than the standard number in more than half of the patients. Among various factors, older age, and tumor location in descending colon and rectum are found to be associated with sub-optimal assessment of lymph nodes. The number of lymph nodes dissected is also associated with survival.