Triple Negative Breast Cancer

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Overview

Triple Negative Breast Cancer (TNBC) is a type of breast cancer characterized by the absence of estrogen receptors (ER), progesterone receptors (PR), and excess HER2 protein. It is classified histologically as a carcinoma and primarily arises in breast tissue. TNBC is known for its aggressive nature and poorer prognosis compared to other breast cancer subtypes due to limited treatment options.

Symptoms

The symptoms of Triple Negative Breast Cancer are generally similar to other types of breast cancer and may include:

• A lump or mass in the breast
• Change in the size, shape, or appearance of the breast
• Dimpling or irritation of breast skin
• Nipple discharge that is not breast milk
• Pain in the breast or nipple
• Swelling of the entire breast or part of the breast
• Changes in the nipple, such as inversion or retraction
• Swollen lymph nodes under the arm or near the collarbone

Standard Treatments

1. Surgery:
   • Lumpectomy: Removal of the tumor and some surrounding tissue.
   • Mastectomy: Removal of one or both breasts, partially or completely.
2. Radiation Therapy: Often used after surgery to eliminate any remaining cancer cells.
3. Chemotherapy:
   • Frequently the main systemic treatment for TNBC, as hormone therapies are ineffective.
   • Common drugs include anthracyclines (e.g., doxorubicin) and taxanes (e.g., paclitaxel).

Targeted Therapy

• PARP Inhibitors: Drugs like olaparib target cancer cells with specific genetic mutations such as BRCA1 or BRCA2. Approved by the FDA in 2018 for certain breast cancer patients.

Experimental Treatments

1. Immunotherapy:
   • Checkpoint Inhibitors: Drugs like pembrolizumab, approved in 2020 for use in combination with chemotherapy in PD-L1 positive TNBC, aim to help the immune system recognize and attack cancer cells.
2. Antibody-Drug Conjugates (ADC):
   • Sacituzumab Govitecan (Trodelvy): Approved in 2020 for metastatic TNBC, combines an antibody targeting cancer cells with a chemotherapy drug.
3. Clinical Trials: Ongoing research includes trials exploring combinations of immunotherapy, chemotherapy, and novel agents.

Side Effects of Treatments

1. Surgery:
   • Pain and tenderness
   • Swelling and bruising
   • Risk of infection
   • Changes in breast shape or texture
2. Radiation Therapy:
   • Fatigue
   • Skin irritation
   • Breast swelling
3. Chemotherapy:
   • Nausea and vomiting
   • Hair loss
   • Increased risk of infection
   • Fatigue
   • Neuropathy (nerve damage)
4. PARP Inhibitors:
   • Anemia
   • Nausea
   • Fatigue
5. Immunotherapy:
   • Immune-related side effects affecting organs like the lungs, liver, or skin
6. Antibody-Drug Conjugates:
   • Neutropenia (low white blood cell count)
   • Diarrhea
   • Fatigue

Modern Developments

• PARP Inhibitors: Became a significant treatment option for BRCA-mutated breast cancer patients post-2018.
• Immunotherapy: Gained FDA approval for certain TNBC cases in 2020, marking a new era in treatment.
• Antibody-Drug Conjugates: Approval of Sacituzumab Govitecan in 2020 reflects ongoing advancements in targeted therapies.

Triple Negative Breast Cancer continues to be a focus of extensive research, with ongoing studies aimed at improving outcomes and expanding treatment options. The information provided here reflects the most recent advancements and understanding as of 2023.