Digital image analysis of pan-cytokeratin stained tumor slides for evaluation of tumor budding in pT1/pT2 colorectal cancer: Results of a feasibility study.

Tumor budding is an independent prognostic factor in colorectal cancer. However, varying degrees of interobserver agreement and reproducibility challenges the use of tumor budding in diagnostics. Immunohistochemical staining of tumor slides with pan-cytokeratin visualizes the budding tumor cells and has been suggested to improve reproducibility. Here we demonstrate the methodology of tumor budding assessment using digital image analysis based on tumor slides stained for pan-cytokeratin, and investigate interobserver agreement, agreement between manual and digital assessment methods and digital reproducibility between users.