Table 1.
Molecular subtype | Prevalence | Characteristics | Treatment response |
---|---|---|---|
Luminal A | 40% | ER+ and/or PR+, HER2+, low Ki67 | Best Prognosis. Respond to endocrine therapy (tamoxifen, fulvestrant and aromatase inhibitors). Less response to chemotherapy as compared to Luminal B. |
Luminal B | 20% | ER+ and/or PR+, HER2+/−, high Ki67 | Better respond to chemotherapy as compared to endocrine therapy due to high Ki67. Poor prognosis as compared to Luminal A |
HER2 | 15–20% | ER−, PR− and HER2+ | Improved prognosis due to drugs like humanized therapeutic monoclonal antibodies trastuzumab & pertuzumab, taxane based chemotherapy, antibody drug conjugate T-DM1 and dual EGFR/HER2 tyrosine kinase inhibitor lapatinib. |
Triple Negative/Basal like | 10–15% | ER−, PR−, HER2− | Worst prognosis due to lack of targeted therapy. Combination of surgery, radiation therapy and chemotherapy. |
Listed are the major subtypes of breast cancer. Also included are their characteristics, prevalence rate and treatment response.
ER+: estrogen receptor positive; ER−: estrogen receptor negative.
PR+: progesterone receptor positive; PR−: progesterone receptor negative.
HER2+: human epidermal growth factor receptor 2 positive.
HER2−: human epidermal growth factor receptor 2 negative.
EGFR: epidermal growth factor receptor; T-DM1: trastuzumab emtansine.