Accuracy of sentinel lymph node biopsy in large and multifocal/multicentric breast carcinoma--a systematic review

Background: While sentinel lymph node biopsy (SLNB) is established in the management of small unifocal breast cancer its role in management of multifocal (MF), multicentric (MC) and larger tumors is still evolving.

Methods: Medline was searched; studies meeting pre-determined criteria were included. Data were extracted and entered into evidence tables.

Results: Twenty six studies met inclusion criteria and reported data on accuracy; no randomized trials were identified. For MF cancers (n = 314 cases), success rate for identification of an SLN was 86-94%, SLN positivity rate 42-59%, false negative rate (FNR) 0-33% and overall accuracy 78-100%. For MC (n = 294 cases): success rate 92-100%, SLN positivity rate 25-61%, FNR 4-8% and accuracy 96-100%. For 'multiple breast cancer' (studies combining MF/MC cases; n = 996 cases): success rate 92-100%, SLN positivity rate 12-63%, FNR 0-25%, and accuracy 82-100%. For larger tumors (n = 1912 cases): success rate 86-100%, SLN positivity rate 49-77%, FNR 3-18% and accuracy 85-98%. For MC/MF and larger cancers overall non-SLN positivity rates were up to 82%; axillary recurrence rates were low but seldom reported.

Conclusion: There are no randomized trials evaluating the safety of SLNB in MF/MC and larger breast cancers. Based on limited evidence, success rate and FNR appear to be similar to those for small unifocal cancers, however node positivity rates are higher and rates of non-SLN positivity are very high. Awareness of these issues is essential when recommending SLNB based axillary management for these higher-risk tumors.