Breast Cancer

Breast cancer is one of the most common cancers among women worldwide, though it can also occur in men. It begins in the breast tissue, most often in the milk ducts (ductal carcinoma) or lobules (lobular carcinoma). It may be invasive (spreading to surrounding tissue) or non-invasive (in situ).

Breast cancer is classified based on the presence of hormone receptors (estrogen and progesterone receptors) and HER2 protein expression. Subtypes include:

• Hormone receptor-positive (HR+)

• HER2-positive

• Triple-negative breast cancer (TNBC) – lacks all three markers and is often more aggressive

Risk factors include age, family history, certain genetic mutations (BRCA1/2), early menstruation or late menopause, hormone replacement therapy, and lifestyle factors.

Common Therapies for Breast Cancer

Treatment depends on the cancer’s type, stage, and receptor status:

1. Surgery

   • Lumpectomy: Removal of the tumor and some surrounding tissue

   • Mastectomy: Removal of one or both breasts

   • Often followed by radiation or systemic therapy

   
   

2. Radiation Therapy

   • Used after surgery to destroy remaining cancer cells, especially after lumpectomy

   
   

3. Hormone (Endocrine) Therapy

   For HR+ breast cancer:

   • Tamoxifen: Blocks estrogen receptors

   • Aromatase inhibitors: Anastrozole, Letrozole, Exemestane (Arimidex, Femara, Aromasin) – reduce estrogen production (mainly for postmenopausal women)

   • Ovarian suppression: Goserelin or surgical removal of ovaries in premenopausal women

     
     

4. Targeted Therapy

   • HER2-positive breast cancer:

     • Trastuzumab, Pertuzumab (Perjeta)

     • T-DM1 (ado-trastuzumab emtansine), Tucatinib

   • CDK4/6 inhibitors (for advanced HR+ cancer): Palbociclib, Ribociclib, Abemaciclib (Ibrance, Kisqali, Verzenio)

   • PI3K inhibitors: Alpelisib (Piqray, for patients with PIK3CA mutations)

   
   

5. Chemotherapy

   • Used for triple-negative, high-risk, or advanced cancers

   • Common drugs: Doxorubicin, Cyclophosphamide, Paclitaxel, Docetaxel, Carboplatin

   
   

6. Immunotherapy

   • For TNBC, especially with PD-L1 expression:

     • Atezolizumab or Pembrolizumab combined with chemotherapy

   
   

   Treatment is highly individualized based on tumor biology and patient factors. Advances in molecular testing and targeted therapies continue to improve outcomes and reduce treatment-related side effects.