Summary

Breast Cancer is the most common malignancy in women (1 in 8 lifetime risk). It encompasses a spectrum from non-invasive in-situ disease (DCIS, LCIS) to invasive carcinoma (Ductal, Lobular). Diagnosis relies on Triple Assessment: Clinical Examination, Imaging (Mammogram/Ultrasound), and Histology (Core Biopsy). Prognosis and treatment are dictated by tumour biology (Grade, Size, Nodal status) and receptor status (ER/PR/HER2). The management paradigm has shifted from "maximum tolerated" radical surgery to "minimum effective" treatment: Breast Conserving Surgery (Lumpectomy) + Radiotherapy is equivocal to Mastectomy for survival. Sentinel Lymph Node Biopsy (SLNB) is the standard of care for axillary staging.

Key Facts

• Lifetime Risk: 1 in 8 women (UK/USA).
• Most Common Type: Invasive Ductal Carcinoma (No Special Type - NST) (~80%).
• Screening: Mammography every 3 years for women 50-70 (UK NHS).
• Genetics: ~5-10% familial (BRCA1, BRCA2, TP53).
• Receptors: 70-80% are ER+ (Targetable with Tamoxifen/AIs). 15-20% are HER2+ (Targetable with Herceptin).
• Triple Negative: 10-15%. Aggressive. Poor prognosis. Needs Chemotherapy.

Clinical Pearls

"Painless Lump": The classic presentation is a painless, hard, irregular lump. Pain is usually hormonal/benign (cyclical mastalgia). However, never dismiss pain in a defined lump.

"Assume Lobular is Bigger": Invasive Lobular Carcinoma (ILC) spreads in "Indian files" (single file lines) and doesn't destroy tissue/form a mass. It feels vague and is often invisible on Mammogram. MRI is essential. The tumour is usually larger than it feels.

"The Axilla is Key": Axillary lymph node status is the single most important prognostic factor.

"Triple Assessment": Concodance is key. If Exam is suspicious (P5), Imaging is suspicious (R5), but Biopsy is benign (B2) -> Repeat the biopsy. Do not stop until all three agree.

TNM Staging

• T1: <2cm.
• T2: 2-5cm.
• T3: >5cm.
• T4: Chest wall/Skin invasion (T4b = Peau d'orange/Ulceration).
• N: N1 (Mobile axillary), N2 (Fixed/Matted), N3 (Internal mammary/Supraclavicular).

          BREAST CANCER DIAGNOSED
          (Triple Assessment confirmed)
                     ↓
          MULTIDISCIPLINARY TEAM (MDT)
                     ↓
     ┌───────────────┴───────────────┐
  OPERABLE                        NEOADJUVANT NEEDED?
  (T1-T3, N0-1)                   (Large T3/T4, HER2+, TNBC)
     ↓                                   ↓
  SURGERY                             CHEMOTHERAPY
  - Breast Conserving (WLE)           (Downstage tumour)
    + Radiotherapy                       ↓
  - OR Mastectomy                     SURGERY
    (+/- Reconstruction)
     ↓
  AXILLARY MANAGEMENT
  - Sentinel Node Biopsy (standard)
  - Clearance (if clinically N+)
     ↓
  ADJUVANT THERAPY (Systemic)
  - Chemotherapy (if High Risk)
  - Herceptin (if HER2+)
  - Endocrine (if ER+)
  - Radiotherapy (if WLE or N+)

1. Surgery: The Breast

• Wide Local Excision (WLE): Removing the lump + 1cm margin.
  • Contraindications: Large tumour:Breast ratio (cosmetically poor), Multifocal disease, Cannot have RT (e.g., previous RT, pregnancy).
  • Rule: Always needs Post-Op Radiotherapy to remainder of breast.
• Mastectomy: Removing all breast tissue.
  • Types: Simple, Skin-Sparing (for reconstruction), Nipple-Sparing.

2. Surgery: The Axilla

• Sentinel Lymph Node Biopsy (SLNB): Inject blue dye + isotope. Remove the first 1-2 nodes.
  • Negative: Stop.
  • Positive (Micro-mets): Often no further surgery needed (radiotherapy covers it - AMAROS).
  • Positive (Macro-mets): Axillary Node Clearance (Level I-III) or Radiotherapy.
• Axillary Clearance: Removal of Level I, II, III nodes.
  • Risk: Lymphoedema (20-30%).

3. Adjuvant Therapy

• Radiotherapy:
  • Mandatory after WLE.
  • After Mastectomy if: T3/T4, >3 positive nodes, positive margins.
• Chemotherapy:
  • Anthracyclines (Epirubicin) + Taxanes (Docetaxel).
  • Indication: Triple Negative, HER2+, High grade, High NPI score.
• Anti-HER2:
  • Trastuzumab (Herceptin). Cardiac toxicity (Echo monitoring required).
• Endocrine Therapy (5-10 years):
  • Pre-menopausal: Tamoxifen (SERM). Risk: Endometrial cancer, DVT.
  • Post-menopausal: Aromatase Inhibitors (Letrozole, Anastrozole). Risk: Osteoporosis (Need DEXA scans).

Nottingham Prognostic Index (NPI)

Used to determine need for adjuvant chemo. Formula: Size (cm) x 0.2 + Grade (1-3) + Nodal Status.

• Score <3.4: Excellent.
• Score >5.4: Poor (Chemo advised).

Oncotype DX

Genomic testing of the tumour biopsy. Predicts benefit of chemotherapy in ER+ HER2- node negative disease. Sways the decision in borderline cases.

Indications

1. Multifocal tumour (more than one quadrant).
2. Large tumour relative to breast size.
3. Patient preference (BRCA carriers often choose bilateral).
4. Failed WLE (margins positive).

Steps

1. Incision: Elliptical, including nipple-areola complex (unless nipple-sparing).
2. Flaps: Skin flaps raised superiorly to clavicle, medially to sternum, laterally to latissimus dorsi.
3. Dissection: Breast tissue dissected off Pectoralis Major muscle (Pectoral fascia taken).
4. Axilla: Separate incision or continuation for SLNB/ANC.
5. Drains: Suction drains placed (high seroma risk).

UK NHS Breast Screening Programme

• Who: Women aged 50-70. (Expanding to 47-73).
• What: Bilateral Mammograms (2 views: MLO/CC).
• Frequency: Every 3 years.
• Aim: Detect small, impalpable cancers (Stage 1). Survival >98%.

Landmark Trials

1. NSABP B-06 (Fisher et al): Proved Lumpectomy + RT = Mastectomy for survival. Ended the era of radical mastectomy.
2. AMAROS Trial: In SLNB-positive cN0 patients, Axillary Radiotherapy is equivalent to Clearance for control, with HALF the lymphoedema risk.
3. ACOSOG Z0011: In T1/T2, cN0 patients undergoing WLE+RT, even if SLNB has 1-2 macro-mets, Clearance is NOT needed.

What is Breast Cancer?

It is a cancer that starts in the breast tissue. It usually begins in the milk ducts (Ductal) or milk glands (Lobular). It is very common, but due to screening and better treatments, survival is higher than ever (over 90% at 5 years).

How is it found?

Most are found by women feeling a lump or by a screening mammogram (X-ray).

How is it treated?

It usually involves surgery to remove the lump (lumpectomy) or the whole breast (mastectomy). We also check the lymph nodes in the armpit. After surgery, most women have radiotherapy. Many also take hormone blocking tablets (like Tamoxifen) for 5-10 years to stop it coming back. Some need chemotherapy.

What about genes?

Only about 5-10% of breast cancers are due to inherited genes like BRCA (the "Jolie Gene"). Most occur by chance as we age.