Evaluation of Tumor Budding In Colorectal Adenocarcinoma

Colorectal cancer (CRC) is among the most prevalent cancers globally, with approximately one to two million new cases diagnosed each year. This makes CRC the third most common cancer and the fourth leading cause of cancer-related deaths, with 700,000 deaths per year, exceeded only by lung, liver and stomach cancers. CRC accounts for about 10% of all cancer diagnoses worldwide (Sung et al., 2021; Masetti et al., 2022) . CRC affects different races and ethnicities at various age groups in distinct ways. Among patients younger than 50 years old, the proportion of CRC is nearly double for Black individuals (16%) compared to White individuals (9%) and Hispanic individuals (6%). In Egypt, CRC ranked the seventh among cancers, following lung, breast, prostate, liver, and bladder cancers (Mounir et al., 2022). Tumor budding (TB) is characterized by the presence of individual tumor cells or small clusters of up to four cells at the invasive margin of a tumor. This histological feature, which indicates the separation of malignant cells from the main tumor mass, has intrigued pathologists since it was first identified in the 1950s (Giordano et al., 2024). Evaluating TB is crucial for improving prognostic accuracy and informing treatment decisions. Tumors with high-grade TB exhibit a significantly lower 5-year Disease-Free Survival (DFS) rate compared to those with low-grade TB. High-grade TB is regarded as a negative prognostic factor and is associated with an increased risk of recurrence (Kyong Shin et al., 2023). TB can be observed in conventional slides when prominent, but careful observation is necessary. A more thorough assessment of TB is more easily achieved if the neoplastic epithelium is highlighted using pan-cytokeratin immunostains (Mishra et al., 2022). Pan-keratin (Pan-CK) antibodies are proteins derived from cytoskeletal intermediate filaments. These antibodies are a mixture designed to detect multiple low and high molecular weight keratins. Their primary pu