Editing Breast cancer (section)

== '''Surgical options''' ==

=== '''Local control''' ===

** Breast-conserving surgery is defined as WLE and whole-breast radiotherapy 
** Indications:
*** Single or multiple lesions that can be excised to leave a satisfactory cosmetic outcome
*** Most T1 and T2 cancers (consider neoadjuvant therapy first for 4-5cm cancers)
*** T3 cancers in larger breasts
** Relative contraindications (none are absolute):
*** T4, N2 or M1
*** Patient preference for mastectomy
*** Collagen vascular disease (especially scleroderma - increased complications from radiotherapy)
*** Large or central tumours in small breasts (that cannot be excised to leave a satisfactory cosmetic outcome - although consider neoadjuvant first)
*** Strong family history of breast cancer, or BRCA1/BRCA2 positive
*** ''Unable or unwilling to have the radiotherapy that should be part of BCS''
*** ''High nuclear grade, presence of lymphovascular invasion and negative steroid hormone receptor status are linked to higher recurrence rates, but are not contraindications to breast conservation''
** Margins
*** Invasive breast cancer: any negative margin is acceptable, i.e., 'no ink on tumour'
*** An involved posterior or anterior margin may not be fixable with surgery, if the original excision extended from right under breast skin back to pectoralis fascia. More often, radiotherapy is the answer.
** Alternative therapies to WLE (remains investigative)
*** Cryoablation
**** Can potentially replace WLE for patients with high surgical risk
**** Argon gas and multiple freeze-thaw cycles
*** RFA
**** RFA alone
**** Excision followed by RFA
***** Under investigation currently
*** Laser ablation
*** High-intensity focused US
*** Microwave ablation
*** Stereotactic radio-ablation

=== '''Regional control''' ===

** SLNB
*** Accurately predicts status of lymph node basin (reflects status of axilla in 97%, with 5% false negative rate)
**** Clinically, if SLNB is negative, ALND is not required
**** For patients with negative SLNB, no difference in overall survival or regional control rate between ALND or no ALND
*** Indications
**** Clinically node-negative T1 or T2 cancer who are undergoing surgery
**** Also consensus that it is appropriate for T3, multifocal/multicentric disease, prior radiation therapy, and prior breast or axillary surgery, but no hard evidence for these cohorts - likely equivalent accuracy to axillary dissection
**** DCIS whenever mastectomy is required, or high-grade, large (>5cm) or palpable DCIS (since there may be a subsequent upstaging based on pathological specimen, which happens about 15% of the time in this cohort). This is because DCIS can be upstaged with excisional biopsy in up to 50% of patients - there is sometimes co-existent cancer.
*** Contraindications
**** T4
**** Inflammatory breast cancer
**** Palpable biopsy-proven positive nodes
*** Previous neoadjuvant therapy
**** Significant controversy over whether SLNB is needed (see 'targeted dissection' below)
*** Outcomes
**** False negative rates <5%
**** Axillary recurrence is very rare after a negative SLNB
** Treatment of the positive sentinel node(s)
*** Estimating risk of having additional positive nodes left behind:
**** Proportional to size of primary tumour, presence of lymphatic vascular invasion, and size of the lymph node metastases
**** 53% of patients with a positive SLNB have more positive nodes at ALND
*** Micrometastases (>0.2mm but <=2mm): additional ALND/axillary radiation confers no advantage
**** 5-year disease-free survival 86.4% with micrometastases, and 89.2% without. Statistically significant, but not considered to be clinically significant.
**** 20% additional non-sentinel node involvement
*** 0, 1 or 2 positive nodes with deposits >2mm
**** If having BCS: post-operative adjuvant whole-breast radiation (which covers most of the axilla) and systemic therapy, but no dissection. Variable between centres as to whether the standard post-BCS radiotherapy fields are altered to include more axilla.

**** If having mastectomy: post-mastectomy radiation
**** ''Note that patients need to have T1 or T2 tumours, need to be CLINICALLY node negative, <3 positive nodes, no evidence of extracapsular extension in axilla, patient needs to commit to radiation and adjuvant systemic therapy '''(Z0011 study)'''.''
**** ''If these conditions are not met, patient will need an axillary dissection''
**** ''May be able to omit dissection too in patients with 2/2 involves nodes from SLNB, but would not give chemotherapy - main role for dissection would be to stage the axilla in patients who would then go on to have chemotherapy''

*** 3 or more pathologically involved nodes will need axillary dissection

**** Can be diagnosed radiologically, clinically or histologically

** Axillary dissection
*** Indications

**** Locally advanced
**** Positive SLNB who are scheduled for accelerated partial breast irradiation
**** Positive SLNB and don't meet Z11 criteria
**** Clinically positive nodes
**** Positive sentinel node after neoadjuvant chemotherapy

** Targeted axillary dissection
*** More for patients with 1-2 level I and II clinical nodes that have neoadjuvant therapy (one study has been done with up to 3 positive nodes). Any more should have dissection. 
*** Re-stage nodes with USS after neoadjuvant therapy - if looks normal, eligible for targeted dissection; if you suspect the axilla is still positive, then should do an ALND
*** Need some sort of localisation - clips, magseed or scoutseed
*** Do SLNB at the same time
*** If ANY node comes back with ANY cancer - generally go back and do ALND
*** No long-term survival data for targeted dissection vs clearance as of 2024
* '''Systemic control'''