The hormone receptor status in breast cancer and the relationship of subtypes with clinicopathological features.

We investigated the relationship between age, grade, tumor size, lymph node metastases and ER, PR, and HER2. However, there was not a significant association between ER, PR, and HER2 and age, tumor size, lymph node metastases (P > 0.05). On the other hand, we found a significant association between grades and ER (P = 0.02) and PR (P = 0.004), but not between grades and HER2 (P > 0.05). High-grade tumors were tumors with the lowest ER, PR positivity rate. Considering the four subtypes, cases aged above 45 years were at most double hormone receptor-positive (75%) and ER-positive/PR-negative (56%), respectively (P < 0.001). High-grade tumors were mostly double hormone receptor-negative and at least double hormone receptor positive. The ER-positive/PR-negative subtype was between these two groups (P < 0.001). The increased tumor size (T3) and increased metastatic lymph node number (N2 and N3) were observed at least in the ER-positive/PR-negative subtype. The majority of cases are in the older age group and invasive ductal carcinoma (IDC) is the most common tumor type. Older cases are most frequently double hormone receptor-positive and ER-positive/PR-negative, respectively. The ER, PR positivity rate is low in high-grade tumors. ER-positive/PR-negative tumors are of a higher grade than double hormone receptor-positive tumors, but they are of a lower grade than double hormone receptor-negative tumors. The increased tumor size and increased lymph node metastasis number are at most in the double hormone negative subtype and at least in the ER-positive/PR-negative subtype. The ER-negative/PR-positive subtype is observed very rarely, which raises the question of whether ER-negative/PR-positive tumors really exist. Further studies are needed to investigate this subtype and its properties.