Dominique Morency1, Sinziana Dumitra1, Elena Parvez1, Karyne Martel2, Mark Basik1, André Robidoux3, Brigitte Poirier4, Claire M B Holloway5, Louis Gaboury3, Lucas Sideris6, Sarkis Meterissian7, Jean-François Boileau8. 1. Jewish General Hospital Segal Cancer Centre, McGill University, Montreal, QC, Canada. 2. Hopital de Saint-Jerome CISSS St-Jerome, Saint-Jerome, QC, Canada. 3. Centre Hospitalier de l'Universite de Montreal, Montreal, QC, Canada. 4. Centre des maladies du sein HSS CHU de Quebec, Universite Laval, Quebec, QC, Canada. 5. Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada. 6. Hopital Maisonneuve-Rosemont, Universite de Montreal, Montreal, QC, Canada. 7. McGill University Health Centre, Montreal, QC, Canada. 8. Jewish General Hospital Segal Cancer Centre, McGill University, Montreal, QC, Canada. jean-francois.boileau@mcgill.ca.
Abstract
BACKGROUND: The sentinel node biopsy following neoadjuvant chemotherapy (SN FNAC) study has shown that in node-positive (N+) breast cancer, sentinel node biopsy (SNB) can be performed following neoadjuvant chemotherapy (NAC), with a low false negative rate (FNR = 8.4%). A secondary endpoint of the SN FNAC study was to determine whether axillary ultrasound (AxUS) could predict axillary pathological complete response (ypN0) and increase the accuracy of SNB. METHODS: The SN FNAC trial is a study of patients with biopsy-proven N+ breast cancer who underwent SNB followed by completion node dissection. All patients had AxUS following NAC and the axillary nodes were classified as either positive (AxUS+) or negative (AxUS-). AxUS was compared with the final axillary pathology results. RESULTS: There was no statistical difference in the baseline characteristics of patients with AxUS+ versus those with AxUS-. Overall, 82.5% (47/57) of AxUS+ patients had residual positive lymph nodes (ypN+) at surgery and 53.8% (42/78) of AxUS- patients had ypN+. Post NAC AxUS sensitivity was 52.8%, specificity 78.3%, and negative predictive value 46.2%. AxUS FNR was 47.2%, versus 8.4% for SNB. If post-NAC AxUS- was used to select patients for SNB, FNR would decrease from 8.4 to 2.7%. However, using post-NAC AxUS in addition to SNB as an indication for ALND would have led to unnecessary ALND in 7.8% of all patients. CONCLUSION: AxUS is not appropriate as a standalone staging procedure, and SNB itself is sufficient to assess the axilla post NAC in patients who present with N+ breast cancer.
BACKGROUND: The sentinel node biopsy following neoadjuvant chemotherapy (SN FNAC) study has shown that in node-positive (N+) breast cancer, sentinel node biopsy (SNB) can be performed following neoadjuvant chemotherapy (NAC), with a low false negative rate (FNR = 8.4%). A secondary endpoint of the SN FNAC study was to determine whether axillary ultrasound (AxUS) could predict axillary pathological complete response (ypN0) and increase the accuracy of SNB. METHODS: The SN FNAC trial is a study of patients with biopsy-proven N+ breast cancer who underwent SNB followed by completion node dissection. All patients had AxUS following NAC and the axillary nodes were classified as either positive (AxUS+) or negative (AxUS-). AxUS was compared with the final axillary pathology results. RESULTS: There was no statistical difference in the baseline characteristics of patients with AxUS+ versus those with AxUS-. Overall, 82.5% (47/57) of AxUS+ patients had residual positive lymph nodes (ypN+) at surgery and 53.8% (42/78) of AxUS- patients had ypN+. Post NAC AxUS sensitivity was 52.8%, specificity 78.3%, and negative predictive value 46.2%. AxUS FNR was 47.2%, versus 8.4% for SNB. If post-NAC AxUS- was used to select patients for SNB, FNR would decrease from 8.4 to 2.7%. However, using post-NAC AxUS in addition to SNB as an indication for ALND would have led to unnecessary ALND in 7.8% of all patients. CONCLUSION: AxUS is not appropriate as a standalone staging procedure, and SNB itself is sufficient to assess the axilla post NAC in patients who present with N+ breast cancer.