Local treatment of the axilla in early breast cancer: concepts from the national surgical adjuvant breast and bowel project B-04 to the planned intergroup sentinel mamma trial

Breast cancer metastasis burden in sentinel nodes analysed using one-step nucleic acid amplification predicts axillary nodal status

BACKGROUND

In breast cancer patients undergoing sentinel lymph node biopsy (SLNB) analysis using one-step nucleic acid amplification (OSNA), clarity is required as to the risk factors for non-sentinel lymph node (NSLN) involvement upon axillary lymph node dissection (ALND). This study aims to identify these factors, including categorising by extent of sentinel node positivity: solitary positive node (solitary), multiple nodes with some positive (multiple incomplete positive), or multiple nodes all of which are positive (multiple all positive).

METHODS

We conducted a cohort study using prospectively collected data on 856 SLNBs analysed using OSNA, from patients with cT1-3 clinically node-negative invasive breast cancer. ALND was performed for 289 positive SLNBs.

RESULTS

NSLN metastases were identified in 73 (25.3%) ALNDs. Significant factors for NSLN involvement on multivariate analysis were: SLNB macrometastases (cytokeratin-19 mRNA count >5000 copies/μl) (adj.OR = 3.01; 95% CI, 1.61-5.66; p = 0.0006), multiple all positive vs. multiple incomplete positive SLNB (adj.OR = 2.92; 95% CI, 1.38-6.19; p = 0.0050), and undergoing mastectomy (adj.OR = 1.89; 95% CI, 1.00-3.55; p = 0.0486). Amongst multiple incomplete positive SLNBs, an 8.8% NSLN risk was identified when only micrometastases were present.

CONCLUSION

Extent of sentinel lymph node positivity measured using OSNA predicts NSLN metastasis risk, aiding decisions surrounding axillary treatment.

Meta-analysis of ultrasound-guided biopsy of suspicious axillary lymph nodes in the selection of patients with extensive axillary tumour burden in breast cancer

Background

Recent studies show that not all patients with breast cancer and positive axillary lymph nodes need additional axillary surgery. A systematic review and meta-analysis of the literature was performed to test the hypothesis that ultrasound-guided biopsy of suspicious nodes can be a useful tool to identify patients with extensive axillary tumour burden.

Methods

PubMed and Embase were searched to identify articles reporting on ultrasound-guided techniques to stage the axilla of patients with breast cancer. The emphasis was to study the number of positive nodes found after axillary lymph node dissection (ALND) following a positive ultrasound-guided biopsy or a positive sentinel lymph node biopsy (SLNB). Information regarding the number of positive nodes thus had to be available. Results were tested for heterogeneity and a meta-analysis was performed.

Results

A total of 894 articles were identified, and 115 were selected based on title and abstract information by two independent reviewers. After extensive review, 18 articles were eligible for analysis. Eight studies reported sufficient data to perform a meta-analysis comparing 532 patients with a positive ultrasound-guided biopsy with 248 patients with a negative ultrasound-guided biopsy but a positive SLNB. The number of involved nodes was significantly higher in patients in whom axillary metastasis was detected by ultrasound-guided biopsy (P < 0·001). No heterogeneity in the observed effect was found (I2 = 22 per cent, P = 0·26).

Conclusion

Patients with breast cancer in whom axillary metastases are detected by ultrasound-guided biopsy have significantly more involved nodes than SLNB-positive patients. This finding enables further preoperative tailoring of axillary treatment in breast cancer.