Different Clinicopathological Characteristics in Indonesian Colorectal Patients with NRAS Mutations and HER2 Over-Expression

OBJECTIVE: This study aims to assess the association of subject characteristics and NRAS mutations with HER2 expression in CRC. METHODS: This research is a cross-sectional study. The research subjects in this study were colorectal cancer patients in the Digestive Surgery division at Dr. Hasan Sadikin Hospital. There were 58 study subjects. Examination of NRAS mutations was carried out by Polymerase Chain Reaction (PCR) from fresh tumour tissue obtained from surgery or colonoscopy. Meanwhile, HER2 examination used the Immunohistochemistry (IHC) method of paraffin blocks for anatomical pathology examination of the same patients. RESULT: HER2 overexpression was found in 6/58 (10.3%) patients with CRC, and from 8 subjects with NRAS mutations, only 1 subject (1.7%) showed overexpression of HER2. Univariate analysis of HER2 expression showed no significant associations to age, sex, histologic feature, tumor location, and NRAS mutations. A significant association was found between HER2 expression and stage of the CRC with p=0.001. CONCLUSION: There is no association between NRAS mutations and HER2 overexpression in colorectal cancer patients.