Association Between Tumor Budding and Lymph Node Metastasis in Surgically Resected Colon Cancer: A Retrospective Observational Study

Background and Objectives: Tumor budding (TB) has emerged as an important histopathological parameter associated with aggressive tumor behavior in colorectal cancer. Increasing evidence has supported its prognostic relevance, particularly regarding lymph node metastasis and adverse pathological features. This study aimed to evaluate whether the established association between TB and lymph node metastasis could be reproduced in our colon cancer cohort and to examine its relationship with other clinicopathological features. Materials and Methods: This retrospective observational study included 136 patients who underwent surgery for colon cancer and whose pathology reports included information on TB. TB was categorized as Bd0, Bd1, Bd2, and Bd3 to evaluate its association with lymph node positivity. The investigation also uncovered the associations between TB and several prognostic indicators, such as T stage, perineural invasion, venous invasion, tumor size, lymphatic invasion and lymph node ratio. Results: Higher TB grade was associated with lymph node positivity in the four-tier analysis (p = 0.012), as well as with lymphatic and venous invasion. However, the association between TB grade and lymph node positivity did not reach statistical significance using the standard ITBCC three-tier classification (p = 0.058). In the primary parsimonious multivariable model, Bd1 was associated with higher odds of lymph node positivity compared with Bd0 (aOR 3.36, 95% CI 1.02–11.02), whereas the estimates for Bd2 (aOR 3.36, 95% CI 0.96–11.75) and Bd3 (aOR 2.76, 95% CI 0.82–9.30) did not reach statistical significance. Conclusions: Higher TB grades were associated with lymph node positivity and other adverse pathological features in unadjusted analyses. In the parsimonious multivariable model, the association with lymph node positivity remained significant only for Bd1, while the estimates for Bd2 and Bd3 did not reach statistical significance. These findings should be interpreted cautiously given the limited sample size and the non-significant association observed using the standard ITBCC three-tier classification.