Objective  The aim of this study was to explore the correlation between the clinicopathological characteristics of colorectal adenocarcinoma and the growth pattern, tumor budding, and CD8⁺T lymphocyte infiltration in anterior invasive margins, and to assess their value as prognostic indicators.

  Methods  Paraffin embedded samples were collected from 126 patients with primary colorectal adenocarcinoma who underwent surgical resection in Zhangye People's Hospital Affiliated to Hexi College from January 2008 to December 2019. A total of 126 pathological sections were stained by immunohistochemistry. Anti-cytokeratin antibodies were used to mark tumor cell budding and anti-CD8 antibody markers T lymphocytes were evaluated.

  Results  In colorectal adenocarcinoma, infiltrative growth patterns and highgrade tumor budding in invasive margins were significantly associated with pathological stage of tumor size (pT) (P=0.029 and P < 0.001, respectively), pathological stage of lymph node metastasis (pN) (P < 0.001 and P=0.023, respectively) and vessel infiltration (P < 0.001 and P < 0.001, respectively). Furthermore, high-grade CD8⁺T lymphocyte infiltration was associated with the absence of lymph node metastases (P=0.050).

  Conclusion  Infiltrative growth patterns and high-grade tumor budding in colorectal adenocarcinoma invasive margins were correlated with patient prognosis. Importantly, these two features are easily detectable (with the help of pan-cytokeratin immunohistochemistry staining), in a reproducible manner. Therefore, we propose that they could be used as prognostic indicators in colorectal adenocarcinoma patients.