Sentinel node biopsy in larger or multifocal breast cancers: to do or not to do.

Background: The use of sentinel node biopsy (SNB) in breast cancer patients with large and/or multifocal tumours is controversial.

Methods: A review of clinical records was undertaken for 213 consecutive patients undergoing SNB for invasive breast cancer from September 2000 to February 2006. The results of SNB and axillary dissection were compared for patients with unifocal or multifocal tumours less than 3 cm and 3 cm or larger. Patient outcomes were also assessed.

Results: The mean number of sentinel nodes removed per patient increased from 2.33 in 2000 to 4.17 in 2006. For patients with unifocal tumours less than 3 cm, 47 of 147 (32.0%) were sentinel node positive compared with 15 of 30 (50%) for multifocal tumours less than 3 cm (P = 0.04), 19 of 28 (67.9%) for unifocal tumours 3 cm or larger (P < 0.001) and 7 of 8 (87.5%) for multifocal tumours 3 cm or larger (P = 0.003). Following axillary dissection, 20 of 48 (41.7%) patients with sentinel node macrometastases were found to have positive non-sentinel nodes, compared with 4 of 20 (20.0%) and 1 of 8 (12.5%) for patients with sentinel node micrometastases and isolated tumour cells. The mean total number of positive nodes was 1.74 compared with 4.21 for unifocal tumours less than or greater than 3 cm, respectively (P = 0.004). No axillary recurrences were detected during the follow-up period.

Conclusion: Although patients with large and/or multifocal tumours were more likely to have a positive sentinel node, the findings provide some indication that SNB may be reliable for staging the axilla in these patients.