Breast cancer is a heterogeneous disease with molecular subtypes that have biological distinctness and different behavior. The objective of this study is to evaluate the value of molecular subtypes in breast cancer management according to a retrospective analysis of breast carcinoma molecular subtypes, histopathological grade, and TNM stage. A retrospective study of 475 paraffin-embedded tissues of breast cancer samples from the First Affiliated Hospital of Guangxi Medical University was performed. Expression of ER, PR, Her-2 and Ki-67 was analyzed to classify molecular subtypes of breast cancer by immunohistochemistry. The differences of molecular subtypes of breast cancers in regard to TNM staging and pathological grade were analyzed using χ(2) tests. Values of P<0.05 were considered statistically significant. The frequency of luminal A, luminal B, HER2-positive luminal B, triple negative and non-luminal HER2-positive subtypes were: 35.5%, 22.5%, 13.1%, 15.2% and 13.7%, respectively. Among the five subtypes of breast cancer, the distribution of pathological grades showed a significant difference (P<0.001). There were significant differences in the distribution of TNM staging among the five subtypes of breast cancer (P<0.001). In addition to traditional prognostic indicators such as TNM staging and pathological grade, molecular subtype may aid clinical practice and research into breast cancer. Different molecular subtypes will lead to different prognosis and therapeutic option. Molecular subtyping is essential for breast cancer management.
Keywords: Clinicopathological classification; breast cancer; histopathological grade; tumor-nodal-metastatic staging.