The results of the biopsy on your breast reached us. The analysis indicates that the tumor is a carcinoma characterized by luminal A. Clinically, they are low grade, slow growing, and have the best prognosis with less incidence of relapse and a higher survival rate. Hormone therapy has shown a high response rate in treating this subtype of breast cancer, while chemotherapy has limited benefits. Breast cancer subtypes are widely recognized into four types: luminal A, luminal B, HER2-positive, and triple-negative. Now, I'll explain those four types in detail.

The four subtypes are categorized based on the expression of hormone receptors, specifically estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), human epidermal growth factor receptor-positive (HER2+), and triple-negative (TNBC). Luminal A tumors have E and/or PR receptors, don't have HER2, and have a low expression of Ki-67, a cell proliferation marker, less than 20%. Luminal B tumors are ER-positive, can be PR-negative, and have high Ki-67 expression, greater than 20%. HER2-positive tumors have high HER2 expression without ER and PR. A lack of ER, PR, and HER2 characterizes triple-negative breast cancer. Next, I'll explain     hormone therapy and chemotherapy.

First, luminal A or B subtype tumors depend on your natural hormones to grow; they will be described as estrogen-positive (ER+) or progesterone-positive (PR+). Hormonal therapy is used to prevent the growth, spread, or recurrence of breast cancer. Next, ki-67 levels at 20% divide subtype luminal into A and B. Luminal B with high Ki-67 expression needs chemotherapy. To sum up, after undergoing breast-conserving surgery to remove the cancer and some normal tissue around it, you need hormone therapy and radiation.