Breast Cancer Screening

Introduction & Epidemiology - Cancer's Early Clues

• Breast cancer: Leading malignancy in Indian women; incidence rising, particularly in urban areas. Accounts for significant morbidity.
• Early detection through screening is crucial for improved prognosis and survival rates.
• Indian scenario:
  • Peak incidence: 40-50 years (a decade earlier than Western counterparts).
  • Presentation often at locally advanced stages, leading to poorer outcomes.
• Screening goal: Identify asymptomatic, early-stage, curable disease.
• Primary modalities: Mammography, Clinical Breast Examination (CBE), Breast Self-Examination (BSE).

⭐ Mammography remains the only screening modality proven to reduce breast cancer mortality, by up to 20-30% in organized screening programs for women aged 50-69 years old.

Mammography - X-Ray Vision

• Primary screening tool for breast cancer; uses low-dose X-rays.
• Standard Views:
  • Cranio-Caudal (CC)
  • Medio-Lateral Oblique (MLO) - visualizes most breast tissue, including axillary tail.
• Technique: Breast compression is crucial for ↓ radiation dose, ↑ image quality, ↓ motion blur.
• Types:
  • Full-Field Digital Mammography (FFDM).
  • Digital Breast Tomosynthesis (DBT/3D): ↑ cancer detection, ↓ recall rates, especially in dense breasts.
• Key Malignant Signs:
  • Spiculated masses.
  • Suspicious microcalcifications (e.g., pleomorphic, fine linear, branching/casting type).
  • Architectural distortion.
  • Developing asymmetry.
• Reporting: BI-RADS (Breast Imaging Reporting and Data System) for standardized assessment and risk stratification.

⭐ DBT (3D Mammography) significantly improves cancer detection rates by 1-2 per 1000 screened and reduces false positives, particularly in women with dense breast tissue.

BI-RADS & Other Modalities - Decoding Reports

• BI-RADS (Breast Imaging Reporting & Data System): Standardized lexicon for mammography, USG, MRI.

  • 0: Incomplete - Needs more views/USG.
  • 1: Negative - Routine screen.
  • 2: Benign - Routine screen.
  • 3: Probably Benign - 6-month follow-up; <2% malignancy risk.
  • 4: Suspicious (4A-low, 4B-mod, 4C-high) - Biopsy.
  • 5: Highly Suggestive of Malignancy (>95% risk) - Biopsy.
  • 6: Known Malignancy - Treatment planning.

• Other Modalities:

  • Ultrasound (USG): Dense breasts, cyst/solid differentiation, palpable lumps, biopsy guidance.
  • MRI: High-risk screen (BRCA, >20% lifetime risk), staging, problem-solving, implants.
  • Tomosynthesis (3D Mammo): ↑Cancer detection, ↓recalls, esp. dense breasts.
  • CEM (Contrast-Enhanced Mammography): Emerging; indications similar to MRI (staging, problem-solving).

⭐ BI-RADS 3 lesions have a <2% likelihood of malignancy; typically managed with short-interval (6-month) follow-up rather than immediate biopsy.

Screening Guidelines (India) - When & Who

• Opportunistic Screening: No national program. Emphasis on awareness.
• Average Risk Women:
  • Age 20+: Monthly Breast Self-Examination (BSE).
  • Age 40-49: Individualized decision for mammography (annual/biennial). Clinical Breast Exam (CBE) recommended.
  • Age 50-74: Mammography every 1-2 years. Annual CBE.
  • Age ≥75: Discuss with doctor; decision based on health status.
• High-Risk Women: (e.g., BRCA mutation, strong family history)
  • Earlier screening: Start mammography by age 25-30 or 10 years before youngest family case.
  • Annual mammography; consider annual MRI.

⭐ Many Indian breast cancers present at a younger age (40-50 years) compared to Western countries, impacting screening considerations.

High‑Yield Points - ⚡ Biggest Takeaways

• Screening mammography is the primary tool for early breast cancer detection.
• BI-RADS classification is crucial for standardized mammography reporting.
• Screening typically begins at age 40-50 years; frequency varies.
• High-risk individuals (e.g., BRCA mutation) need earlier screening, often with MRI.
• Digital Breast Tomosynthesis (DBT) improves cancer detection, especially in dense breasts.
• Triple assessment (clinical exam, imaging, biopsy) is key for symptomatic patients, not for screening asymptomatic women.