Search

Introduction: Colorectal cancer (CRC) is the second most reported cancer in Malaysia. Although there are advancements in cancer therapy research, CRC is still facing challenges with 50% relapses risk and treatment resistance issues. Responding to these problems, many studies have been conducted to improve and search for new potential biomarkers. Efficient biomarkers are in need for prognostic and more competent therapeutic regimens. Tyrosine kinase receptors (TKR) including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-3 (HER3) are classified as cell surface receptors and were related to prognosis and therapeutic assessment in many of CRC cases. Analysing two related biomarkers brings more information with the potential to serve as dual targeted antibodies. This study aims to evaluate EGFR, HER3 and EGFR/HER3 immunohistochemical expressions in CRC, with the hope of determining its possible relationship with demographic and clinicopathologic parameters. Methods: 94 samples were retrieved from Department of Pathology, Hospital Serdang archive between the year 2008 and 2015. Tissue sections were made from formalin fixed paraffin embedded (FFPE) samples of primary colorectal adenocarcinoma. EGFR and HER3 protein expressions were tested using immunohistochemistry (IHC). IHC staining was scored with semi-quantitative scoring system. Association of EGFR, HER3 and EGFR/HER3 expressions with demographic and clinicopathologic parameters were evaluated using chi-square test. Results: Immunopositivity were found in 42.6% of CRC samples in both EGFR and HER3 staining. EGFR cytoplasmic and luminal side of cell membrane expression was associated with non-Malay (p=0.038) and non-diabetic (p=0.044) samples. The cytoplasmic expression of HER3 was found to be more in females (p=0.027) and lymph node metastasis (p=0.049). EGFR expression was associated with HER3 expression (p=0.001) and EGFR/HER3 co-expression was related to moderate tumour grading (p=0.030). Conclusion: EGFR and HER3 were found to be overexpressed in CRC samples. Their expressions may indicate potential prognostic factors with more advanced tumour conditions. Co-expression of EGFR and HER3 pairs may play a crucial role for adjuvant therapy as dual targeted antibodies. [ABSTRACT FROM AUTHOR]