Prognostic significance of epidermal growth factor receptor gene mutations and human epidermal growth factor 2 expression in breast carcinoma metastatic to the liver

Background: Breast cancer is the most prevalent cancer among females, and metastatic disease is not curable and is treated palliatively. Members of the ErbB family have an important role in the development and progression of breast cancer. The aim of this study was to determine the relationship between epidermal growth factor receptor (EGFR) gene mutation, human epidermal growth factor 2 (HER2) expression, hormone receptor statuses, and clinicopathological parameters in liver metastases from breast cancer. Materials and Methods: This study included 41 patients diagnosed with liver metastasis from breast carcinoma, based on morphological and immunohistochemical findings, in our pathology laboratory between 2011 and 2018. EGFR gene mutations were analyzed by polymerase chain reaction (PCR) in these cases. Results: EGFR gene mutation analysis was performed by PCR, and no mutations were detected. HER2 and ER statuses of the primary breast tumor were available in 23 cases. HER2 status conversions were present in 9 cases (39.1%); however, this was not statistically significant (P = 0.197). Estrogen receptor (ER) conversions were present in 4 cases (17.4%); however, this was not statistically significant (P = 1.000). Progesterone receptor (PR) conversions were detected in 10 cases (45.5%). There were 10 (45.5%) cases with PR-positive primary tumors and PR-negative liver metastases. No cases with a PR-negative primary tumor developed a PR-positive liver metastasis (P = 0.02). Conclusions: No EGFR gene mutations were detected in any of our cases by PCR. There was no statistically significant relationship between clinicopathological parameters and EGFR mutation. The comparison of ER, PR, and HER2 expression between the primary tumor and metastases revealed status conversions in some cases. However, only PR conversion was statistically significant. Studies on EGFR gene mutations that include larger series are warranted to identify the candidates who can benefit from targeted therapies.