Background: As neoadjuvant chemotherapy (NAC) is increasingly used to downstage patients with breast cancer, the timing of the sentinel node (SN) biopsy has become an important issue. This review was conducted to determine the accuracy of SN biopsy following NAC.
Methods: We searched Medline, Embase and Cochrane databases from 1993 to February 2009 for studies on patients with invasive breast cancer who underwent SN biopsy after NAC followed by an axillary lymph node dissection (ALND).
Results: Of 574 eligible studies, 27 were included in this review with a total study population of 2148 patients. The pooled SN identification rate was 90.9% (95% confidence interval (CI)=88.0-93.1%) and the false-negative rate was 10.5% (95% CI=8.1-13.6%). Negative predictive value and accuracy after NAC were 89.0% (95% CI=85.1-92.1%) and 94.4% (95% CI=92.6-95.8%), respectively. The reported SN success rates were heterogeneous and several variables were reported to be associated with decreased SN accuracy, i.e. initially positive clinical nodal status.
Conclusions: There is a potential role for SN biopsy following NAC which could be considered on an individual basis. However, there is insufficient evidence to recommend this as a standard procedure. Further research with subgroup analysis using variables reported to be associated with decreased SN accuracy is required in order to clearly define its value in the subgroups of breast cancer patients.