Clinicopathological features of breast cancer with different molecular subtypes in Chinese women

A retrospective study was performed to explore the relationship between molecular subtypes and clinicopathological features of breast cancer in Chinese women. Six hundred and twenty-eight Chinese women with breast cancer were classified into four molecular subtypes according to their estrogen receptor (ER), progesterone receptor (PR) and Her-2 status. The prevalence rate of each molecular subtype was analyzed. Relationship between the subtypes and clinicopathologic features was determined. The distribution of molecular subtypes was as follows: luminal A 46.5%, luminal B 17.0%, basal 21.5%, HER2/neu 15.0%. The subtypes had no significant difference under different menopausal status. However, in the age-specific groups, the age group of ≤35 years was more likely to get basal cell-like cancer (36.9%). Statistically significant differences were found among molecular subtypes by age, nuclear grade, tumor size, lymph node (LN) metastasis, tumor stage by American Joint Committee on Cancer (AJCC), radiotherapy but not by chemotherapy, types of surgery. After adjusting for several relative confounding factors, the basal subtype more likely had lower nodal involvement in both the incidence of LN metastasis (≥1 positive LN) and incidence of high-volume LN metastasis (≥4 positive LN). The HER2/neu subtype had higher nodal involvement in the incidence of high-volume LN metastases. After adjusting for relative confounding factors, the HER2/neu subtype more likely had higher AJCC tumor stages. It was suggested that there existed close relationship between molecular subtypes and clinicopathological features of breast cancer. In addition, the breast cancer subtypes have been proven to be an independent predictor of LN involvement and AJCC tumor stage. These findings are very important for understanding the occurrence, development, prognosis and treatment of breast cancer in Chinese population.