Post-Neoadjuvant Chemotherapy Sentinel Lymph Node Biopsy Is Reliable in Breast Cancer: A Prospective Study in Chinese Patients.
Authors: Liao N. , Zhang G. , Liu Y. , Li X. , Yao M. , Wang K. , Zu J. , Wu Y. 
Published: December 2010

Abstract
Background: Sentinel lymph node biopsy (SLNB) for breast cancer patients before chemotherapy is currently being practiced in a world wide scale. However, obvious disadvantage of a second surgical procedure after neoadjuvant chemotherapy (NAC) has been noted. Considering that metastasis in axillary lymph node would probably be eradicated by NAC making axillary lymph node dissection (ALND) completely unnecessary, SLNB performed after NAC could be a choice. Nonetheless, it is still controversial for a fear of impaired detection rate and accuracy. Therefore we carried out a prospective study by one single surgical team to compare SLNB between post-NAC patients and non-NAC patients.Methods: Operable invasive breast cancer patients confirmed by core needle biopsy before treatment with clinical N0 or N1 axilla were enrolled. Exclusion criteria included noninfiltrating cancer, inflammatory carcinoma and clinically fixed axillary lymph node. SLNB followed by ALND was performed in one single operation by the same surgical team for all patients either afer NAC or without NAC. Single methylene blue was used for SLN tracing with 2ml injected subcutaneously into the areola area and the mapping procedure was started 5 minutes later. SLN and ALND specimens were examined by 2 independent pathologists under standard pathological procedures.Results: From Dec 2007 to May 2009, 50 patients without NAC and 49 patients after NAC were prospectively enrolled. SLNB and ALND were performed as scheduled. In the post-NAC group, 19 had clinical N0 axilla and 30 had N1 axilla before treatment. SLNB was successful in 46 patients with 1.6 SLNs detected on average (range 1 to 5) and the average number of lymph nodes taken out in ALND was 15.4 (range 7 to 33). We found 9 with SLN(+)/ALN(+), 5 with SLN(+)/ALN(-), 2 with SLN(-)/ALN(+), and 29 with SLN(-)/ALN(-). In the non-NAC group, 40 had clinical N0 axilla and 10 had N1 axilla before surgery. SLNB was successful in 48 patients with 1.7 SLNs detected on average (range 1 to 6) and the average number of lymph nodes taken out in ALND was 16.8 (range 8 to 38). We found 4 with SLN(+)/ALN(+), 10 with SLN(+)/ALN(-), 1 with SLN(-)/ALN(+), and 33 with SLN(-)/ALN(-). Detection rate, accuracy, and false negative rate was 93.9% (46 of 49), 95.7% (44 of 46) and 11.8% (2 of 17) in post-NAC group and 96% (48 of 50), 97.9% (44 of 46) and 6.7% (1 of 15) in non-NAC group, respectively. There was no statistical difference between post-NAC group and non-NAC group in either detection rate (p=0.409), accuracy (p=0.525) or false negative rate (p=0.548).Conclusions: This prospective study in Chinese breast cancer population shows that post-NAC SLNB has both satisfactory detection rate and accuracy with acceptable false negative rate, being comparable to non-NAC patients. Our results also showed that using methylene blue only in SLNB for breast cancer is an ideal choice where radio detection method is not available.Summary of pathological resultsGrouppost-NAC (N=49)non-NAC (N=50)SLNB successful4648Average SLNs detected1.6 (range 1 to 5)1.7 ( range 1 to 6)Average ALNs taken out15.4 (range 7 to 33)16.8 (range 8 to 38)SLN+ / ALN-94SLN+/ ALN+510SLN- / ALN+21SLN- / ALN-2933
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1014.