Table of Contents
Introduction
Breast cancer is the most common cancer among women worldwide and a leading cause of cancer-related mortality. It is a heterogeneous disease involving genetic, hormonal, and environmental factors. Advances in screening, molecular biology, and targeted therapy have significantly improved survival rates, but challenges remain in early detection and access to care.
Epidemiology
- Accounts for 11.7% of all cancers globally (GLOBOCAN 2020).
- Leading cancer in women, surpassing lung cancer in incidence.
- Lifetime risk: 1 in 8 women.
- In India, accounts for ~14% of all cancers in women; rising incidence in urban areas.
Risk Factors
- Genetic: BRCA1, BRCA2, TP53 mutations.
- Hormonal: Early menarche, late menopause, nulliparity, hormone replacement therapy.
- Lifestyle: Obesity, alcohol, sedentary habits.
- Environmental: Radiation exposure, carcinogens.
- Family history of breast/ovarian cancer.
Pathophysiology
- Begins as uncontrolled proliferation of ductal or lobular epithelial cells.
- Progression from atypical hyperplasia → carcinoma in situ → invasive carcinoma.
Molecular classification :
- Luminal A: ER+, PR+, HER2–, slow-growing, good prognosis.
- Luminal B: ER+, HER2+/–, more aggressive.
- HER2-enriched: HER2+, aggressive, responsive to trastuzumab.
- Triple Negative (TNBC): ER–, PR–, HER2–, aggressive, limited treatment options.
Clinical Features
- Painless breast lump (most common).
- Nipple changes: retraction, discharge (bloody).
- Skin dimpling (“peau d’orange”).
- Axillary lymphadenopathy.
- Advanced disease: bone pain, cough, weight loss, hepatomegaly.
Investigations
- Triple Assessment: Clinical exam + Imaging + Biopsy.
Imaging:
- Mammography (screening for women >40).
- Ultrasound (dense breasts, young women).
- MRI (high-risk patients).
Biopsy: Core needle biopsy → histopathology.
Receptor testing (ER, PR, HER2) for treatment planning.
Staging: TNM classification, PET-CT for metastasis.
Screening
- Mammography every 2 years for women aged 50–69 (WHO).
- High-risk women (BRCA mutations): MRI + mammogram starting earlier.
- Self-breast examination and clinical breast exam awareness campaigns.
Treatment Modalities
Management is multidisciplinary, depending on tumor stage, receptor status, and patient factors.
1. Surgery
- Breast-conserving surgery (lumpectomy) + radiotherapy.
- Mastectomy ± reconstruction.
- Sentinel lymph node biopsy/axillary dissection.
2. Radiotherapy
- Post-lumpectomy to prevent recurrence.
- Palliative use in bone/brain metastases.
3. Chemotherapy
- Used in triple-negative and advanced stages.
- Neoadjuvant therapy for large tumors.
4. Hormonal Therapy
- For ER/PR positive tumors.
- Tamoxifen (premenopausal), Aromatase inhibitors (postmenopausal).
5. Targeted Therapy
- HER2+ tumors: Trastuzumab, Pertuzumab.
- PARP inhibitors (Olaparib) for BRCA-mutated tumors.
6. Immunotherapy
- Checkpoint inhibitors (Atezolizumab, Pembrolizumab) for TNBC.
Recent Research & Advances
- Liquid biopsy for early detection and monitoring recurrence.
- Oncotype DX and MammaPrint gene profiling to guide chemotherapy use.
- Immunotherapy trials showing promise in triple-negative cancers.
- Circulating tumor DNA (ctDNA) as a marker for minimal residual disease.
- Advances in breast reconstruction techniques improving quality of life.
Complications
- Lymphedema (post-surgery).
- Recurrence and metastasis.
- Chemotherapy side effects: infertility, cardiotoxicity.
- Psychosocial issues: depression, anxiety, body image concerns.
Prognosis
Depends on stage at diagnosis and tumor biology.
5-year survival rates:
- Localized: ~99%.
- Regional spread: ~86%.
- Metastatic: ~29%.
Early detection greatly improves outcomes.
Breast cancer : Frequently Asked Questions (FAQs)
1. Can men get breast cancer?
Yes, though rare (<1% of cases).
2. Is breast cancer hereditary?
5–10% are due to genetic mutations (BRCA1/2).
3. Does every breast lump mean cancer?
No, most lumps are benign (fibroadenoma, cyst), but all must be evaluated.
4. Can breast cancer be prevented?
Not entirely, but risk can be reduced with healthy lifestyle, limiting alcohol, and regular screening.
5. What is triple-negative breast cancer?
It lacks ER, PR, and HER2 receptors – aggressive but responds to chemotherapy and immunotherapy.
6. Is mammography safe?
Yes. Radiation exposure is minimal and benefits outweigh risks.
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