KRAS and H1F1a expression in colorectal cancer and its association with the tumor clinicopathological features

Background: Colorectal cancer represents one of the commonest cancers worldwide. It is ranked as the fourth commonest one accounting for nearly 10 % of all cancers. Some tumor markers may help identify the prognosis of the Colorectal cancer . One of those markers is the Kirsten Rat Sarcoma Protein (KRAS). KRAS is one of the proteins important for the transduction cascade of the epidermal growth factor (EGF) and Hypoxia inducible factor HIF1a which is essential mediators of cellular response to hypoxia, regulate gene expression for tumor angiogenesis, glucose metabolism, and resistance to oxidative stress. Aim: To study the expression of KRAS and H1F1a and its relationship with other clinical and histopathological prognostic factors in patients with Colorectal cancer . Methods: This is a retrospective immunohistochemical study on 55 resection specimens from 55 Colorectal cancer cases. The pathology specimens were collected from July 2019 to February 2020. Tumor tissues were prepared as formalin-fixed, paraffin-embedded specimens. The paraffin blocks were sectioned at the 5 microns thickness. Then the collected sections were stained with hematoxylin & eosin (H&E) for histopathological revision and immune-histochemical staining for KRAS and H1F1a proteins. Results: In our sample, only 54% of cases were positive for KRAS expression, and 50.9% were positive for H1F1a. KRAS and H1F1a expression showed no statistically significant relationship with the different clinical, and histopathological parameters including age groups, sex, histological variant, and tumor stages. Conclusion: immune-histochemical staining staining with KRAS and H1F1a could be a promising modality for screening of mutations of Colorectal cancer with less cost and comparable results to molecular studies. However, the interpretation of our results is limited by the small sample size of our population.