Clinico-pathological evaluation of tumor budding in the oncological progression of colorectal cancer.

Introduction: Tumor budding (TB), defined as the presence of individual neoplastic cells or isolated groups of up to 4 cells at the front of tumor invasion, has become an adverse prognostic marker in colorectal cancer (CRC) in recent decades. The prognostic impact of TB in CRC remains not clearly defined and histological methods for its evaluation vary depending on the center. The objective of this study is to investigate the association between TB and CRC, in terms of oncological evolution and pathological stage.

Methods: A retrospective observational study was conducted, including patients undergoing curative oncological surgery for CRC between January 2017 and December 2022. The effects of TB on disease-free survival (DFS) and overall survival (OS) were evaluated according to the Kaplan-Meier curves.

Results: In 78 cases TB was described in the pathology report. TB was present in 56 patients (71.8%), divided into the following categories: low grade in 22 (39.3%), intermediate grade in 17 (30.4%) and high grade in 17 (30.4%). The proportion of patients who presented lymph node metastases, lympho-vascular and perineural invasion was significantly higher in patients with TB (26.8% vs 0%, P=.008; 41.1% vs 4.5%, P=.002; 16.1% vs 0% P=.054; respectively). DFS was 86.3% in low-grade TB, 75.3% in intermediate-grade TB, and 70.3% in high-grade TB. Cases with intermediate and high grade were associated with a shorter OS compared to the low grade group (93.7% and 75.4% vs 100% P=.012, respectively).

Conclusion: These results suggest that TB expression may be a useful risk factor as a prognostic factor for the detection of lymph node metastasis, local recurrence, and distant metastasis in CRC.