ObjectiveTo investigate the effect of lymph node size on the pathological stage of colorectal cancer patients and analyze the relation between lymph node size and prognosis. MethodsThe patients with colorectal cancer underwent elective surgery in the People’s Hospital of Xindu District from 2017 to 2021 were retrospectively collected. The visible and palpable lymph nodes were harvested and the routine histological examination was performed. The effect of lymph node size on the pathological stage and prognosis of colorectal cancer patients were analyzed. ResultsA total of 300 patients with colorectal cancer were enrolled, with harvested 4 442 lymph nodes. Among them, measurement of lymph node size was completed in 4 086 lymph nodes, 198 lymph nodes (108 patients) of whom were found to be positive. There were 1 360 small lymph nodes (diameter <3 mm), 32 lymph nodes (24 patients) of whom were positive. Among the 24 patients, only 4 patients when detecting large lymph nodes (diameter ≥3 mm) was negative, but which was positive when detecting small lymph nodes (diameter <3 mm). The results of logistic regression analysis showed that the lymph node diameter <3 mm had a lower probability of positive lymph node (lymph node diameter 3–6 mm as a reference, OR=0.49, P=0.015). After excluding 4 cases of subtotal colon resection and 4 patients with obvious abnormalities of lymph node, 292 cases were included to analyze the relation between the lymph node size and the number of detected lymph nodes, no correlation was found between the lymph node size and the number of detected lymph nodes in 292 integral patients or 106 patients with positive lymph node (r=0.148, P=0.075; r=–0.032, P=0.821). Moreover, no statistical difference of the lymph node size was found between the patients with ≥12 and <12 lymph nodes detected (P>0.05). However, in the 186 patients with negative lymph nodes, a positive correlation was found between the lymph node size and the number of detected lymph nodes (r=0.317, P=0.002), and lymph node diameter was significantly larger in the patients with ≥12 lymph nodes detected than in the patients with <12 lymph nodes detected (P=0.002). There were no statistical differences in the disease-free survival and overall survival among the patients with different lymph node sizes (<3 mm, 3–6 mm, and >6 mm) in both patients with positive and negative lymph nodes (P>0.05). ConclusionFrom the analysis results of this study, it is found that lymph node size has little effect on lymph node pathological staging, and no correlation between lymph node size and disease-free survival or overall survival is found in both patients with positive and negative lymph nodes.