Molecular and Immunohistochemical Biomarkers in Colorectal Carcinoma - A Single Center Study

Colorectal cancer is the third most common malignancy in the world and among the most frequent causes of cancer-related death. Our study aimed to evaluate the molecular profile of the patients diagnosed with colorectal carcinoma at Clinical Hospital Acibadem-Sistina in Skopje.

This study is retrospective-prospective, conducted at the Department of histopathology and cytology, at Clinical Hospital Acibadem-Sistina in Skopje. Tissue samples from surgical material from 152 patients diagnosed with CRC were processed for molecular and immunohistochemical analysis. KRAS and BRAF mutations were analyzed, and MMR status was obtained. In 90 metastatic cases, evaluation of HER2 and PDL-1 expression was performed on a tissue microarray.

Among 152 analyzed patients diagnosed with colorectal carcinoma, the majority were males (98, 64.47%) compared to females (54, 35.53%). The mean age was 68.4±11.3 years; the median age was 70 years. KRAS/NRAS mutations were detected in 47(31%) of patients, BRAF mutations in 11(7%) patients, and mismatch repair gene deficiency (MMRd) was found in 15(10%) of patients. HER2 positive expression was present in 36(40%) of patients, and 17(19%) of patients showed PDL-1 expression. In the group of 17 PDL1-positive tumors, a cutoff of more than 1% positive tumor cells was detected in 10 cases, more than 10% tumor cells in 4 cases, and more than 50% tumor cells in 3 cases. From 36 HER2 positive cases, 32(32,5%) were with score 2+, and 4(4,4%) with score 3+.

Continued research into molecular mechanisms and biomarkers holds the promise of further improving CRC outcomes through personalized and effective interventions.