Axillary de-escalation — B-32 staging, micrometastatic omission, radiotherapy swap and clipped-node triage

Examiner prompts with model answers

Sentinel standard — stage, do not clear, the node-negative axilla. Sentinel nodes are removed in 97.2% with 97.1% accuracy and 9.8% false-negative rate, dual radio-blue in 65.1% with 0.7% blue allergy, and more than one node without excisional biopsy lowers the miss rate — with shoulder, volume and sensory morbidity all favouring sentinel surgery over dissection at 3 years.^[2]

Upfront omission — Z0011 and micrometastases. T1-T2 nonpalpable disease with 1-2 positive sentinels treated by lumpectomy, tangential irradiation and systemic therapy needs no dissection with 10-year survival 86.3% versus 83.6% — while micrometastatic 2 mm-or-smaller disease without extracapsular extension needs no dissection with 10-year disease-free survival 76.8% versus 74.9% and 4% versus 13% lymphoedema.^[5][8]

Radiotherapy swap — control equal, morbidity decides. Sentinel-positive cT1-2 disease gives 10-year axillary recurrence 0.93% versus 1.82% with no survival difference, while lymphoedema runs 24.5% versus 11.9% — radiotherapy preferred for less arm morbidity.^[10]

Observation boundary — SOUND small cancers. Tumours up to 2 cm with negative ultrasound randomise to sentinel surgery or nothing with 13.7% occult positivity yet 97.7% versus 98.0% distant control — spare surgery only when missing pathology leaves adjuvant decisions unchanged.^[11]

Post-chemotherapy staging — clips rescue the miss rate. Sentinel biopsy before chemotherapy detects 99.1% but after cN+ to ycN0 conversion detects 80.1% with 14.2% false-negative rising to 24.3% with one node; baseline post-chemotherapy false-negative rate 12.6% falls to 6.8% when the clipped node is retrieved in the sentinel packet versus 19.0% when stranded — with targeted dissection cutting sentinel-alone 10.1% to 1.4% combined and 2.0% for TAD with dissection.^[13][12][14]