Immunophenotypic Characterization of Colorectal Cancer in a Tertiary Care Hospital: A Cross sectional Study

BACKGROUND Colorectal carcinoma (CRC) is the third most common malignancy and the second leading cause of cancer-related deaths worldwide. It encompasses a heterogeneous group of epithelial tumors with distinct histologic, molecular, and clinical features. Immunophenotypic and molecular profiling play crucial roles in tumor classification, prognostication, and guiding targeted therapy in the era of personalized medicine. This study aimed to evaluate the clinicopathologic, immunophenotypic, and molecular characteristics of CRC in Nepal Mediciti Hospital, providing local data to enhance diagnostic and therapeutic strategies. METHODS A hospital-based analytical cross-sectional study was conducted on 25 histopathologically confirmed CRC cases diagnosed at Nepal Mediciti Hospital between January 2021 and December 2024. Following ethical approval, demographic, clinical, histologic, immunohistochemical and molecular data were retrieved and analyzed using statistical software SPSS version 26. RESULTS The mean patient age was 55.08 years (range: 24–86), with a male-to-female ratio of 1.5:1. The caecum and ascending colon were the most frequent tumor sites. Moderately differentiated adenocarcinoma was the predominant histologic type. 85.71% of resection specimen showed CK20 positivity. All of cases (100%) showed positive nuclear staining for CDX2 and SATB2. KRAS and BRAF mutations were identified in 32% and 8% of cases, respectively, with no NRAS mutations detected. Mismatch repair deficiency (dMMR) was noted in 12% of cases, all among females under 50 years. CONCLUSIONS The clinicopathologic, immunophenotypic, and molecular profiles of CRC in this study parallel global trends. This study did not demonstrate a significant correlation between MSI status and either tumor site or grade. It emphasizes on the relevance of molecular testing for prognosis, targeted therapy, and hereditary cancer screening.