Triple-negative breast cancer types exhibit a distinct poor clinical characteristic in lymph node-negative Chinese patients.

Comparative studies on the clinical features and outcomes of triple-negative subgroups to human epidermal growth factor receptor-2 (HER-2) overexpression, and luminal A and B subgroups in lymph node-negative breast cancer patients, are important to correctly evaluate clinical prognosis. A total of 1132 Chinese breast cancer patients were enrolled in a retrospective analysis. We characterized and identified prognostic information in the triple-negative subgroup [estrogen receptor (ER)-, progesterone receptor (PR)- and HER-2-negative] and compared that to HER-2 overexpression, and the luminal A and B subgroups. By using immunohistochemical staining, the triple-negative subgroup showed 17% (193/1132) in the whole group. However, HER-2 overexpression, and the luminal A and B subgroups were 11.2, 47.9 and 23.9%, respectively. Tumors in the triple-negative subgroup showed a higher histological grade (P=0.025) and lower invasive ductal carcinoma (P=0.007), compared to the three subgroups. More patients in the luminal A subgroup had received adjuvant chemotherapy (P=0.007). The difference of disease-free survival rates among the four subgroups was significant (P=0.0001). The P-value for overall survival was 0.0598. No significant difference among the four subgroups in lymph node-positive and non-chemotherapy breast cancers was found. From our data the poor clinical outcomes were independent of age, histological grade, tumor size, lymph nodal status, chemotherapy and clinical stages. Our data suggest that the triple-negative subgroup exhibits a distinct poor clinical outcome, especially in lymph node-negative Chinese breast cancer patients.