Sentinel node biopsy and large (≥3 cm) breast cancer.

BACKGROUND

Sentinel node biopsy is an accurate method for staging the axilla in early (small) breast cancers. However, data for the role of this technique for large breast cancers remain limited.

METHOD

From the Royal Adelaide Hospital Sentinel Node database and the SNAC trial database, 100 subjects were identified with clinically node negative, large (≥3 cm) primary breast cancer who had undergone sentinel node biopsy and immediate axillary clearance. The pathology results from the sentinel node and axillary specimens were analysed.

RESULTS

Average tumour size was 3.91 cm (range 3-10 cm) and 65 of 100 cases had metastatic disease in the axillary nodes. A sentinel node was successfully identified in 93 out of 100 cases with an average of 1.75 sentinel nodes sampled. Sixty-two per cent (58 out of 93) were sentinel node positive and 43% (43 out of 100) had a positive non-sentinel node. The false negative rate following successful sentinel node identification was 4.9% (3 out of 61).

CONCLUSION

Sentinel node biopsy was an accurate tool for staging the axilla with a false negative rate comparable to that seen in small tumours. However, given the increased incidence of metastases with larger cancers, further prospective investigation is warranted.