Breast Cancer: An Overview of Introduction, Types, Pathogenesis,Lab Diagnosis, Treatment, Prevention, and Keynotes

Introduction

Breast cancer is the most common malignancy among women worldwide and a leading cause of cancer-related mortality. It arises from the epithelial cells of the breast, most commonly from the ducts or lobules. Although predominantly affecting women, breast cancer can also occur in men. Early detection and advances in diagnostic and therapeutic strategies have significantly improved survival rates.

Types of Breast Cancer

Breast cancer is classified based on histology, receptor status, and molecular features.

1. Ductal Carcinoma
   • Ductal carcinoma in situ (DCIS) – non-invasive
   • Invasive ductal carcinoma (IDC) – the most common type
2. Lobular Carcinoma
   • Lobular carcinoma in situ (LCIS)
   • Invasive lobular carcinoma (ILC)
3. Special Types
   • Medullary carcinoma
   • Mucinous carcinoma
   • Tubular carcinoma
   • Inflammatory breast cancer
4. Molecular Subtypes
   • Hormone receptor–positive (ER/PR)
   • HER2-positive
   • Triple-negative breast cancer (TNBC)

Pathogenesis

Breast cancer develops due to genetic, hormonal, and environmental factors.

• Mutations in BRCA1, BRCA2, TP53, and PTEN genes
• Prolonged exposure to estrogen
• Abnormal cell proliferation and impaired apoptosis
• Accumulation of genetic alterations leading to invasion and metastasis
• Tumor angiogenesis and immune evasion

Laboratory Diagnosis

Specimens

• Breast lump biopsy
• Fine-needle aspiration cytology (FNAC)
• Core needle biopsy

Diagnostic methods

• Histopathological examination – gold standard
• Immunohistochemistry (IHC) for ER, PR, HER2
• Molecular testing (BRCA mutation analysis)
• Tumor markers: CA 15-3, CEA (monitoring)

Treatment

Treatment depends on cancer stage, type, and receptor status.

• Surgery: lumpectomy, mastectomy
• Chemotherapy
• Radiotherapy
• Hormonal therapy (tamoxifen, aromatase inhibitors)
• Targeted therapy (trastuzumab for HER2-positive tumors)
• Immunotherapy (selected cases)

Prevention

• Regular breast self-examination
• Mammography screening
• Genetic counseling for high-risk individuals
• Healthy lifestyle: balanced diet, physical activity
• Avoidance of alcohol and tobacco
• Prophylactic surgery in high-risk cases (BRCA mutation)

Keynotes

• The most common cancer in women
• Ductal carcinoma is the predominant type
• Strong genetic and hormonal influence
• Early diagnosis improves prognosis
• IHC guides targeted therapy
• A multimodal treatment approach is essential.

Further Readings

1. https://www.who.int/news-room/fact-sheets/detail/breast_cancer
2. https://www.cancer.org.au/cancer-information/types-of-cancer/breast_cancer
3. https://www.mayoclinic.org/diseases-conditions/breast_cancer/symptoms-causes/syc-20352470
4. https://www.mdanderson.org/cancer-types/breast_cancer.html
5. https://www.nature.com/articles/s41392-024-02108-4
6. https://www.researchgate.net/publication/394256020_Breast_Cancer_A_Comprehensive_Review_of_Epidemiology_Risk_Factors_Diagnosis_and_Treatment
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC9139759/
8. https://ergsy.com/information/breast_cancer-testing-and-treatment-nhs/breast_cancer/487/413
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC11693720
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC6861781
11. https://globalhealthconnector.com/news/communities-unite-in-nigeria-for-breast_cancer-awareness