Sentinel lymph node biopsy is a reliable method for lymph node evaluation in neoadjuvant chemotherapy-treated patients with breast cancer.

Sentinel lymph node (SLN) mapping in patients with breast cancer treated with neoadjuvant chemotherapy has been debated by surgeons as a result of potential compromise of lymphatic drainage. Whether clinicopathologic variables traditionally associated with SLN positivity differ in patients who have been treated with neoadjuvant chemotherapy has not been well studied. Patients diagnosed with breast carcinoma who underwent neoadjuvant chemotherapy, definitive breast surgery, sentinel node biopsy (SNB), and axillary lymph node dissection (ALND) were retrospectively identified over a 75-month period. Clinicopathologic parameters including age, clinical tumor and node stage, neoadjuvant chemotherapy regimen, pathological tumor and node stage, lymphovascular invasion (LVI), SLN and non-SLN involvement, and extranodal extension were recorded. Ninety-seven patients met inclusion criteria. Ninety-eight per cent had successful SLN mapping. Eight patients with negative SLNs had positive ALND (false-negative rate, 8.3%). Clinicopathological variables associated with SLN status included clinical axillary status (P = 0.038), pathologic tumor size, and nodal status and LVI (P < 0.001). Extranodal extension was significantly associated with non-SLN status (P = 0.004). In patients achieving a pathologic complete response (PCR), SNB remained feasible and accurate (false-negative rate, 11.6%). Successful SLN mapping in patients who have undergone neoadjuvant chemotherapy is highly accurate with a low false-negative rate even in patients who have a PCR.