Is triple-negative breast cancer more aggressive than breast cancer with positive hormone (estrogen and progesterone) and Human Epidermal growth factor Receptor 2 (HER2) receptors?

From the Guidelines

Triple negative breast cancer is indeed more aggressive than hormone receptor-positive and HER2-positive breast cancers, with a poorer prognosis due to its lack of response to hormonal therapies and HER2-targeted treatments. This cancer type tends to grow and spread more quickly, has higher recurrence rates within the first 3-5 years after diagnosis, and has fewer targeted treatment options 1. The characteristics of triple negative breast cancer, including its association with African-American race, deprivation status, younger age at diagnosis, more advanced disease stage, higher grade, high mitotic indices, family history of breast cancer, and BRCA1 mutations, contribute to its aggressive nature 1. Some key points to consider about triple negative breast cancer include:

• It represents 10%–20% of invasive breast cancers and is regularly reported to be three times more common in women of African descent and in pre-menopausal women 1
• Women with triple negative breast cancer experience the peak risk of recurrence within 3 years of diagnosis, and the mortality rates appear to be increased for 5 years after diagnosis 1
• Treatment typically relies on surgery, radiation therapy, and chemotherapy regimens, with some patients potentially benefiting from PARP inhibitors like olaparib if they have specific genetic mutations The aggressive nature of triple negative breast cancer stems from its molecular characteristics, including genomic instability, higher proliferation rates, and greater likelihood of spreading to vital organs like the brain and lungs rather than bones, which is more common in hormone-positive cancers. Overall, the current understanding of triple negative breast cancer highlights the need for more epidemiological studies to integrate aetiological and lifestyle factors for prevention of incidence and death, as well as more population-based information on the clinical and biological relevance from cancer registries 1.

From the Research

Characteristics of Triple Negative Breast Cancer

• Triple negative breast cancer (TNBC) is characterized by the absence or low expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2) 2, 3, 4, 5, 6
• TNBC accounts for about 15% of breast cancer cases in the U.S. and is known for high relapse rates and poor overall survival (OS) 2
• TNBC is a genetically diverse, highly heterogeneous, and rapidly evolving disease that challenges the ability to individualize treatment for incomplete responders and relapsed patients 2

Aggressiveness of Triple Negative Breast Cancer

• TNBC is considered an aggressive subtype of breast cancer with high recurrence, metastatic, and mortality rates 3, 5, 6
• The lack of traditional receptor targets contributes to the heterogeneous, aggressive, and refractory nature of TNBC tumors, resulting in limited therapeutic strategies 4
• TNBC is overrepresented among Black and pre-menopausal women and is associated with significant psychological and treatment-related burdens, including financial toxicity 6

Comparison with Hormone Receptor Positive Breast Cancer

• TNBC is more aggressive than hormone receptor positive breast cancer, which can be treated with hormonal receptor and HER-2 antagonists 3
• The absence of estrogen, progesterone, and HER2 receptors in TNBC limits the use of targeted therapies, making it more challenging to treat than hormone receptor positive breast cancer 4, 5
• Current treatment options for TNBC are primarily based on chemotherapy, with some targeted therapies showing promise in improving clinical outcomes 2, 4, 5