All patients should be considered for breast conserving surgery if feasible.  This should include the use of oncoplastic procedures and neoadjuvant therapy when appropriate.  If oncoplastic procedures aren’t available locally then pathways should be established so all patients can access this type of surgery across the country.

Margins

Offer further surgery (re-excision or mastectomy, as appropriate) after breast conserving surgery where invasive cancer and/or DCIS is present within less than 1mm of the radial margins.

Further surgery after breast conserving surgery where invasive and/or DCIS is within less than 1mm of the anterior or posterior margin should only be considered if full thickness excision has not been undertaken and should be clearly documented in the initial operation note.

cN0 at diagnosis

• Patients undergoing primary surgery should undergo axillary staging with sentinel lymph node biopsy (SLNB). 
• Perform SLNB  using a dual agent mapping technique.  Single agent mapping may be used where it is established practice that is supported by local audit.

cN1+ at diagnosis

• Offer axillary node clearance (ANC) to patients with pathologically proven lymph node metastases on pre-operative ultrasound-guided core biopsy.
• Targeted axillary dissection (TAD) may be considered in carefully selected patients with low risk disease and limited axillary node involvement on imaging: e.g cT1, low grade, ductal type, 1 or 2 abnormal nodes only.  Explain this limited evidence base for this practice to patients and ensure that audit of this practice is  performed.

cN0pN1+ (SLNB positive)

• Following MDT discussion offer further treatment (Axillary radiotherapy or ANC).
• Do not offer further axillary treatment after primary surgery to people who have only micrometastasis or isolated tumour cells in their sentinel lymph node(s).
• Consider no further axillary treatment in those patients who have undergone breast conserving surgery and fit the criteria based on RCR consensus document (≥70yrs, ER+, HER2-, Grade 1-2, adjuvant endocrine therapy). 

cN0 at diagnosis

Perform SLNB after NACT with a dual agent mapping technique. 

cN1+ at diagnosis

• Place a clip  into the biopsied positive node at diagnosis.
• If clinical and radiological findings after NACT suggest a complete disease response consider performing a targeted axillary dissection (TAD - Localisation of biopsied node along with SLNB using dual mapping technique). 
• If performing a TAD,  attempt to remove at least three nodes  especially if the biopsied/clipped node has not been marked at diagnosis and/or localisation isn’t possible.
• If following a TAD pathology reveals a pathological complete response, then offer axillary radiotherapy.
• If following a TAD pathology reveals residual disease then offer completion axillary node clearance.  Axillary radiotherapy may be considered following discussion at MDT in patients with very limited residual disease (e.g. limited disease in only one node).
• If clinical and radiological findings after NACT demonstrate limited or no evidence of response in the axillary nodes, then offer patients ANC.

• Do not routinely perform SLNB for patients with a pre-operative diagnosis of DCIS in patients undergoing breast conserving surgery. 
• SLNB may be considered when performing oncoplastic breast conserving procedures as an alternative to mastectomy where the planned excision will preclude future successful mapping.
• Offer SLNB to patients undergoing mastectomy for DCIS.

• Consider BR (immediate or delayed) in all suitable patients when a mastectomy has been recommended.

• Post-mastectomy radiotherapy can potentially have adverse impacts on BR. This should be acknowledged and discussed with the patient.  This is particularly evident with implant-based reconstruction and is associated with higher rates of complications, implant loss rates and poorer cosmetic outcomes in patients undergoing implant based breast reconstruction. The use of implant only reconstruction in patients with previous, or planned chest wall radiotherapy should be considered carefully.

• If certain reconstruction techniques are not available locally then pathways should be established to ensure all reconstructive techniques are accessible for patients across the country.

1. Overview | Early and locally advanced breast cancer: diagnosis and management | Guidance | NICE
2. Gandhi A, Coles C, Makris A, Provenzano E, Goyal A, Maxwell AJ, Doughty JC. Axillary Surgery Following Neoadjuvant Chemotherapy – Multidisciplinary Guidance From the Association of Breast Surgery, Faculty of Clinical Oncology of the Royal College of Radiologists, UK Breast Cancer Group, National Co-ordinating Committee for Breast Pathology and British Society of Breast Radiology.  Clinical Oncology 2019;31:664-668
3. Postoperative radiotherapy for breast cancer: UK consensus statements | The Royal College of Radiologists (rcr.ac.uk)
4. Gilmour A, Cutress R, Gandhi A, Harcourt D, Little K, Mansell J, Murphy J, Pennery E, Tillett R, Vidya R, Martin L. Oncoplastic breast surgery:  A guide to good practice.  EJSO 2021;47:2272-2285