Reliability of core needle biopsy in the diagnosis of breast cancer

Abstract

We investigated the concordance between the histopathological and immunohistochemical results of core needle biopsy (CNB) and surgical specimens in order to evaluate the reliability of the CNB in the diagnosis and management of breast carcinoma. We studied breast carcinomas collected retrospectively between 2015 and 2017. Immunohistochemical staining for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2(HER2) and Ki-67 was conducted on archived tissue. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CNB compared with surgical specimens. The kappa test (κ) was used for concordance analysis. A total of 81 cases were selected. The concordance of histological diagnosis between CNB and surgical specimens was 98.8% (κ = 0.903). The sensitivity, specificity, PPV and NPV of the diagnosis of invasive carcinoma of no special type were 100%, 83.3%, 98.7%, and 100%, respectively. ER expression displayed a total concordance (κ = 1). For PR expression, sensitivity, specificity, PPV and NPV were 100%, 87%, 95.1%, and 100%, respectively, with a concordance of 96.3% (κ = 0.905). The concordance of the HER2 status was 87.6% as there were 10 discordant findings (κ = 0.722). The concordance of the Ki-67 index was only 55.6% (κ = 0.193). The overall concordance of molecular subtypes was only 58% (κ = 0.424). In conclusion, CNB is reliable in determining histological subtypes, hormone receptor expression, and HER2 status. However, its reliability is limited in for evaluating Ki-67 index and the subsequent diagnosis of molecular subtypes.