Intratumoral Budding and Tumor Microenvironment in Pretreatment Rectal Cancer Biopsies Predict the Response to Neoadjuvant Chemoradiotherapy

Tumor budding at the invasive tumor front (peritumoral budding) is an established prognostic factor in colorectal cancer. However, the significance of intratumoral budding (ITB) in pretreatment biopsies is still uncertain. Our study aims to investigate the association of ITB and tumor microenvironment in pretreatment rectal cancer biopsies with pathologic response to neoadjuvant chemoradiotherapy. Pretreatment biopsies of low-grade rectal cancer from 37 patients who underwent resection after neoadjuvant chemoradiotherapy were retrospectively reviewed to evaluate ITB, type of tumor stroma, and intraepithelial lymphocytes. ITB was counted on a single hotspot in 1 HPF upon pan-keratin immunohistochemical staining. Intraepithelial lymphocytes was graded semiquantitatively as “absent” (≤2/HPF) or “present” (>2/HPF). The tumor stroma was classified as either immature type or maturing type. In pretreatment biopsies, ITB was observed in 34/37 patients (92%). High-grade ITB was significantly associated with a poor pathologic response to neoadjuvant chemoradiotherapy (tumor regression score 2 to 3, P
Source: Applied Immunohistochemistry and Molecular Morphology - Category: Chemistry Tags: Research Articles Source Type: research