Relationship between molecular typing and axillary lymph node metastasis in breast cancer patients with different T stages and its clinical significance

Objective:To explore the relationship between molecular typing and axillary lymph node metastasis in the breast cancer patients with different tumor size(T)stages and its clinical significance,and to guide the application of sentinel lymph node biopsy to avoid the postoperative complications caused by axillary lymph node dissection.Methods:The clinicopathologic features and immunohistochemistry results of 2 100 breast cancer patients whose clinical data were complete with first treatment of surgical treatment and the T of 0-5cm were retrospectively analyzed.The relationship between various molecular subtyping of breast cancer and axillary lymph node metastasis was analyzed.The differences of axillary lymph node metastasis rates between various molecular subtypes were compared.The relevant factors of axillary lymph node metastasis were analyzed by multivariate Logistic regression analysis.Results:The axillary lymph node metastasis rates among various molecular subtyes had obvious differences when the T of breast cancer were 1cmT≤2cm,2cmT≤3cm,and 3cmT≤4cm(P0.05).In 0cm≤T≤1cm,1cmT≤2cm,2cmT≤3cm,and 3cmT≤4cm,Luminal B type had the higher lymph node metastasis rate,and the rates were 40.00%,29.41%,50.00%,and 65.22%.When the tumor size was 4cmT≤5cm,the axillary lymph node metastasis rate of Her-2type was the highest,about 75%.In all the breast cancer T grouping,Triple-negative type had the lowest axillary lymph node metastasis rate.Her-2overexpression was the independent risk factor for the metastasis of axillary lymph node.Conclusion:The characteristics of axillary lymph node metastasis are different in the breast cancer patients with various molecular subtypes.In the patients with Luminal B type and Her-2type the sentinel lymph node needs to be more cautious.Her-2overexpression is the independent risk factor for the metastasis of axillary lymph node.Molecular typing is an important complement to the traditional breast cancer pathological type and stage and it can further suggest the biological behavior of breast cancer and contribute to the development of individualized treatment.