Change of the hormonal receptor expression in recurred breast cancer

Abstract

Purpose: Expression of hormone receptors in breast cancer is one of the most important factors in determining its therapeutic plan and prognosis. Various studies have been ongoing regarding resistance in anti-hormone and target therapy of primary and metastatic breast cancers, and hormonal receptor mutation has been pointed out as one of the possible reasons. The purpose of this study was to analyze hormonal receptor changes in primary and metastatic breast cancer patients and to investigate possible influential factors. Methods: Out of 1,620 breast cancer patients who were surgically treated from 1997 to 2013, 38 patients were selected whose tissue samples were adequate for detecting presence of hormonal receptor expression. The presence of estrogen receptor (ER), progesteron receptor (PR), human epidermal growth factor 2 (HER2) receptor mutations were retrospectively analyzed by immunohistochemical staining and fluorescence in-situ hybridization. Results: The positive rate of ER, PR, HER2 receptors were 50%, 47.3%, and 24.3% respectively. In comparison to primary breast cancer, the rate of receptor mutations in recurred and metastatic tissues were 23.6%, 26.3%, and 6.6%; the rate of changes in receptors from positive to negative and negative to positive showed no statistically significant difference. Conclusion: The expression of hormonal receptors in breast cancer tissue is considered as one of the significant factors in pathologic findings, and it is crucial in determining the course of treatment. Recently, performing a tissue biopsy of metastatic lesion in addition to surgically removing the primary cancer has been in trend. Since there are various treatment options for breast cancer including hormonal therapy, chemotherapy, surgery and target therapy, a biopsy of metastatic lesion should be carried out actively in order to increase the specificity of tissue pathology.