[Feasibility of sentinel lymph node biopsy peri-neoadjuvant chemotherapy in breast cancer]

To explore the feasibility of sentinel lymph node biopsy in peri-neoadjuvant chemotherapy for breast cancer patients.

A total of 252 breast cancer patients underwent sentinel lymph node biopsy and axillary lymph node dissection from January 2005 to November 2011, including 150 patients in pre-neoadjuvant chemotherapy group and 102 in post-neoadjuvant chemotherapy group. The feasibility of sentinel lymph node biopsy under different clinical states of axillary lymph node was compared.

No significant difference was found in the detection rate (98.5% vs 92.8%), false negative rate (6.7% vs 7.9%), accuracy (98.4% vs 91.9%) and negative sensitivity (97.9% vs 88.0%) of sentinel lymph node biopsy before neoadjuvant chemotherapy whether the axillary lymph node was negative or positive. However, the transfer rate of sentinel lymph node in the positive group was significantly higher than the negative group (28.8% vs 67.5%, P = 0.000). False negative rate of sentinel lymph node in biopsy was significantly higher in the post-neoadjuvant chemotherapy group than the pre-neoadjuvant chemotherapy group (7.5% vs 23.9%, P = 0.024) and the accuracy/negative sensitivity decreased significantly (95.1% vs 83.5%, P = 0.005/94.4% vs 75.0%, P = 0.003). No statistical difference existed in the detection rate, false negative rate, accuracy, negative sensitivity of sentinel lymph node in biopsy before and after neoadjuvant chemotherapy in patients with negative axillary lymph node for a preliminary diagnosis. The accuracy of sentinel lymph node decreased significantly in biopsy after neoadjuvant chemotherapy in patients with positive axillary lymph node confirmed pathologically for a preliminary diagnosis compared with before (98.4/83.7%, P = 0.010), the transfer rate of sentinel lymph node increased significantly (28.8/53.7%, P = 0.005) and negative sensitivity reduced significantly (97.9/68.0%, P = 0.007); Compared with pre-neoadjuvant chemotherapy, the negative sensitivity decreased significantly in patients with axillary lymph node positive confirmed pathologically and then turned negative (94.4% vs 57.1%, P = 0.005) while the transfer rate of sentinel lymph node increased significantly (28.8%/65.0%, P = 0.003).

Sentinel lymph node before neoadjuvant chemotherapy may accurately predict axillary lymph node metastasis. The detection rate, false negative rate, accuracy, negative sensitivity of sentinel lymph node in biopsy after neoadjuvant chemotherapy in patients with negative axillary lymph node for preliminary diagnosis are the same before neoadjuvant chemotherapy. Patients with positive axillary lymph node for a preliminary diagnosis are unsuitable for sentinel lymph node biopsy whether axillary lymph node turns negative or not after neoadjuvant chemotherapy.