01Purpose and principlesWhat the treatment does and how it fits into care.
Axillary management separates detection, staging and regional control. Ultrasound identifies suspicious morphology and provides a target for preoperative needle biopsy. Sentinel-node biopsy maps the first draining nodes and supplies pathological staging with far less tissue removal than clearance. Clearance treats a nodal basin but increases seroma, numbness, shoulder restriction and lymphoedema. Radiotherapy can provide regional control in selected settings without being biologically equivalent to staging surgery.
The size of nodal deposits matters. Isolated tumour cells and micrometastases do not lead to further axillary treatment after primary sentinel surgery under NICE. Macrometastasis generally prompts an offer of clearance or radiotherapy, with a specific shared-decision exception for one or two sentinel macrometastases after breast conservation when whole-breast radiotherapy and systemic therapy are advised. The exact neoadjuvant pathway depends on how nodal disease was proven and marked before treatment.
Key points
- Pretreatment axillary ultrasound is required for early and locally advanced invasive breast cancer; sample morphologically abnormal nodes under ultrasound guidance.
- Use sentinel-node biopsy rather than clearance to stage an ultrasound-normal axilla or one with a negative targeted node biopsy, because microscopic disease may remain despite normal imaging.
- NICE recommends the dual localisation technique with isotope and blue dye for sentinel-node biopsy in a validated service.
- Pathologically proven nodal metastasis on pretreatment ultrasound-guided biopsy leads to axillary node clearance in the NICE primary-surgery pathway, while neoadjuvant pathways require planned specialist reassessment.
- After primary surgery, offer further axillary treatment for one or more sentinel-node macrometastases; discuss omission in the specific one-to-two-node conservation, whole-breast radiotherapy and systemic-therapy group.
- Do not offer further axillary treatment for sentinel-node micrometastases alone or isolated tumour cells; more surgery can add lymphoedema without proven survival benefit.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
Cortical thickening, focal bulge, round shape or loss of fatty hilum can identify a node requiring targeted needle tissue.
No suspicious clinical or ultrasound finding lowers macroscopic burden but cannot exclude microscopic metastasis, which is why sentinel staging remains relevant.
A metastatic deposit above 2 mm is a macrometastasis and has different further-treatment implications from a micrometastasis or isolated cells.
Arm swelling, heaviness, reduced shoulder movement, neuropathic pain and recurrent cellulitis suggest axillary-treatment consequences needing early assessment.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Pretreatment axillary ultrasoundFirst step - Why
- Identify suspicious nodes and select a representative target before surgery or systemic therapy.
- Interpretation and limitations
- Morphology is more informative than size alone. Record which node was sampled and whether a clip was placed when neoadjuvant treatment is planned.
- 02
Ultrasound-guided core or cytology - Why
- Confirm metastatic carcinoma in an abnormal node and influence the planned axillary route.
- Interpretation and limitations
- A positive adequately identified sample proves involvement. A negative result must be judged against imaging suspicion and sample adequacy.
- 03
Sentinel-node biopsy - Why
- Pathologically stage the draining axilla when preoperative assessment has not proven nodal disease.
- Interpretation and limitations
- Report the number of nodes removed and involved, largest deposit and relevant cell-count assessment. Isolated tumour cells are single cells or small clusters no larger than 0.2 mm. Micrometastases are larger than 0.2 mm but no larger than 2 mm; more than 200 cells in one histological cross-section can also fulfil the micrometastasis criterion when no deposit exceeds 2 mm. Macrometastases exceed 2 mm. The pathologist applies the full current breast TNM9 criteria to small dispersed deposits, rather than assigning a category from size alone. Distinguish primary-surgery findings from residual disease after neoadjuvant therapy.
- 04
Post-treatment axillary assessment - Why
- Evaluate response in a previously involved axilla and plan surgery after neoadjuvant systemic therapy.
- Interpretation and limitations
- Imaging response alone does not prove nodal sterilisation. The pathway should account for the originally biopsied node and local validated technique.
04Treatment approachPreparation, options, escalation and aftercare.
01Worked case: ultrasound-normal axillaStage with the least morbid operationFirst stepA patient having primary surgery for invasive cancer has a normal axillary examination and ultrasound.+
- 1In this illustrative primary-surgery case, pretreatment axillary ultrasound is normal and there has been no neoadjuvant systemic therapy. The patient discusses sentinel mapping and its allergy, sensory, seroma and lymphoedema risks, then chooses breast surgery with sentinel-node biopsy rather than routine axillary clearance.
- 2The team performs the planned dual isotope and blue-dye procedure. Pathology reports one 0.8 mm deposit in a sentinel node, with no macrometastasis in the other sampled nodes. The measured deposit is a micrometastasis, not a deposit exceeding 2 mm.
- 3At postoperative review, the team applies the NICE primary-surgery recommendation: no further axillary treatment is offered for sentinel micrometastases alone. Breast radiotherapy and systemic decisions are considered from their own indications; this axillary decision does not mean that all adjuvant treatment is unnecessary.
- 4The patient has a small resolving seroma, improving shoulder movement and no arm swelling at review. She receives exercise advice and demonstrates that she knows the contact route for new swelling, infection or persistent restriction. The agreed regional plan and the observed recovery are documented.
- 5The clinician explains why the same small deposit after neoadjuvant treatment would require its separate specialist pathway. The case endpoint is a verified deposit category, an enacted decision to avoid further axillary treatment and documented follow-up, rather than an assumed absence of all future recurrence risk.
02Biopsy-proven node pathwayPlan regional control before theatreAxillary ultrasound before primary surgery shows an abnormal node and core confirms metastatic breast carcinoma.+
- 1Confirm the node identity, pathology and breast primary are concordant and complete clinical staging.
- 2Discuss axillary node clearance under the NICE primary-surgery recommendation and include radiotherapy interactions and lymphoedema risk.
- 3If neoadjuvant treatment is being considered, mark and document the involved node where required and agree the post-treatment surgical pathway before therapy.
- 4Coordinate physiotherapy information, baseline arm assessment and postoperative surveillance for morbidity.
03Limited sentinel macrometastasis pathwayMake further treatment explicitAfter breast conservation, one of three sentinel nodes contains a macrometastasis; whole-breast radiotherapy and systemic therapy are advised.+
- 1Verify deposit size, extranodal features, number involved and that preoperative ultrasound-guided biopsy was normal or negative.
- 2Offer further axillary treatment as the general NICE recommendation, comparing clearance and radiotherapy.
- 3Also discuss benefits and risks of omitting further axillary treatment in this specific one-to-two sentinel-macrometastasis conservation group, using a trial where available.
- 4Record patient preference, regional radiotherapy fields and the final multidisciplinary rationale, then monitor arm morbidity.
05Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Before treatment, record clinical and ultrasound nodal status, biopsy result, node identity and clip placement so the original disease can be found after response.
- After sentinel surgery, document node count and the largest deposit category rather than using an undifferentiated positive or negative label.
- Assess wound, seroma, sensation and shoulder range early and provide evidence-based exercise information as recommended by the updated NICE lymphoedema section.
- Longer term, respond promptly to arm or chest-wall swelling, heaviness, skin infection and functional restriction with specialist lymphoedema assessment.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Ultrasound starts the pathway
Sentinel biopsy follows a normal or adequately sampled negative axilla; a proven metastasis changes the planned operation before theatre.
Deposit size changes action
Macrometastases, micrometastases and isolated tumour cells are not interchangeable, and the pathology category determines whether further axillary treatment is offered.
Omission is context-specific
Discussion of no further treatment for one or two macrometastases applies to a defined conservation, whole-breast radiotherapy and systemic-therapy setting.
Neoadjuvant planning starts early
Marking the biopsied node and agreeing the post-treatment technique before therapy prevents uncertainty after nodes shrink or normalise.
07Common pitfallsFrequent interpretation and management errors.
- 01
Skipping pretreatment axillary ultrasound can lead to sentinel surgery when macroscopic nodal disease could have been diagnosed before treatment.
- 02
Performing routine clearance for an ultrasound-normal axilla discards the lower-morbidity sentinel staging route.
- 03
Treating isolated tumour cells as macrometastatic disease drives unnecessary further axillary intervention.
- 04
Generalising axillary-treatment omission to mastectomy, multiple macrometastases or no systemic and radiotherapy coverage misuses a narrow shared-decision pathway.