A 48-year-old woman from Mumbai presents with a 2 cm palpable mass in the upper outer quadrant of her left breast. Mammography confirms a suspicious lesion with microcalcifications. Core needle biopsy shows invasive ductal carcinoma, grade II. Sentinel lymph node biopsy reveals metastatic disease in 2 of 3 nodes. Staging CT chest/abdomen/pelvis shows no distant metastases. Her tumour is ER/PR positive, HER2 negative. What is the most appropriate surgical management for this patient?

Explanation

## Clinical Assessment This patient has: - T2 (2 cm), N1 (2/3 positive sentinel nodes), M0 disease = **Stage IIB breast cancer** - ER/PR positive, HER2 negative = luminal A phenotype - Positive sentinel nodes mandate completion axillary lymph node dissection (ALND) ## Surgical Decision Tree ```mermaid flowchart TD A[Invasive breast cancer]:::outcome --> B{Tumour size & nodal status}:::decision B -->|T1-2, N0| C[BCT or mastectomy eligible]:::action B -->|T1-2, N1-3 or T3-4 any N| D[Mastectomy preferred]:::action C --> E[If BCT: SLNB + RT]:::action D --> F[Modified radical mastectomy + ALND + RT]:::action A --> G{Positive sentinel nodes?}:::decision G -->|Yes| H[Complete ALND required]:::action G -->|No| I[SLNB alone sufficient]:::action ``` ## Why Modified Radical Mastectomy? **Key Point:** Positive sentinel nodes (N1) in a T2 tumour constitute stage IIB disease. While breast-conserving therapy (BCT) *can* be offered with ALND + radiotherapy, **mastectomy is the preferred surgical approach** for: - Node-positive disease (reduces local recurrence risk) - Tumours ≥2 cm with nodal involvement - Better cosmesis and psychological outcomes in some patients **High-Yield:** The 2012 ACOSOG Z11 trial showed BCT + ALND + RT is equivalent to mastectomy for T1-2, N0-1 disease *if* patient accepts radiotherapy. However, in Indian practice and most guidelines, **node-positive disease (N1) favours mastectomy** as the standard approach, especially when combined with T2 size. **Clinical Pearl:** Modified radical mastectomy removes breast tissue, nipple-areola complex, and axillary nodes (levels I, II, ±III) while preserving pectoralis muscles — the standard for operable breast cancer with nodal involvement. ## Adjuvant Therapy | Modality | Indication | Rationale | |----------|-----------|----------| | Radiotherapy | Post-mastectomy with N1 | Reduces locoregional recurrence | | Hormonal therapy | ER/PR positive | Endocrine therapy (tamoxifen or AI) for 5–10 years | | Chemotherapy | N1 disease | Consider if high-risk features (grade II + node-positive) | **Mnemonic:** **ALND** = Axillary Lymph Node Dissection (mandatory when sentinel nodes are positive).