Retrospective study of the differences of biomarker expression between primary lesions of breast cancer and corresponding lymph node metastases

Abstract

Objective To investigate the difference of the expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 and Ki-67 protein between primary lesions of breast cancer and its synchronous ipsilateral lymph node metastasis, as well as its clinical implications. Methods Retrospectively analyze invasive breast cancer patients treated in Peking University First Hospital from January 2012 to May 2016. The IHC expressions of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 and Ki-67 protein in both the primary and lymph node metastatic lesions are compared and analyzed statistically. The count data were represented as n(%), and comparsion between groups were evaluated using the McNemar test. Results One hundred and fifty-six patients were included, of which on 2 cases (1.3%), estrogen receptor status of primary lesions is different from that of lymph node metastases(P=0.500); on 10 cases(6.4%), progesterone receptor status of primary lesions is different from that of lymph node metastases(P=0.344); on 28 cases (18.0%), Ki-67 protein status of primary lesions is different from that of lymph node metastases(P=0.000 18); on 3 cases (1.9%), human epidermal growth factor receptor 2 status of primary lesions is different from that of lymph node metastases (P=1.000). Conclusion There may be difference between primary lesions and lymph node metastases in the expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 and Ki-67 protein, which can provide a reference for individualized treatment of breast cancer patients. Key words: Breast neoplasms; Lymph nodes; Genetic heterogeneity; Biomarker