Intraoperative assessment of sentinel lymph node by one-step nucleic acid amplification in breast cancer patients after neoadjuvant treatment reduces the need for a second surgery for axillary lymph node dissection.
OBJECTIVE
Sentinel lymph node (SLN) biopsy has been shown to be both accurate and feasible for women who receive neoadjuvant chemotherapy (NAC). Intraoperative assessment of SLN by frozen sections can produce false negative results. The aim of this study was to compare two different techniques of intraoperative assessment of SLN in breast cancer patients treated with NAC: frozen section (FS) and molecular assay (OSNA).


METHODS
A multicenter cohort of 320 consecutive breast cancer patients treated with NAC between 2010 and 2014 was analyzed. FS was performed intraoperatively in 166 patients (H&E cohort) and OSNA in 154 patients (OSNA cohort).


RESULTS
A mean of 2.15 SLNs by FS and 1.22 SLNs by OSNA was assessed (p = 0.03). SLN metastasis was found in 44 patients (26.5%) by FS and in 48 (31.2%) by OSNA (p = 0.4). There was no statistical significance in rates of macrometastasis (75%), micrometastasis (20.5%) or ITCs (4.5%) when assessed by FS compared to OSNA (52.3%, 36.3% and 11.4%, respectively) (p = 0.06). There were 10 patients in the H&E cohort with positive-SLN in the definitive pathology assessment with negative intraoperative FS. When OSNA and definitive pathology were compared, there were no differences in rates of macrometastasis (61.1%), micrometastasis (33.3%) nor ITCs (5.6%) (p = 0.5). Fifty-four patients in the H&E cohort and 44 in the OSNA cohort had ALND after positive-SLNs. ALND was performed in a second surgery in 10 patients (18.5%) in the H&E cohort for intraoperative FS false negative results, 90% being micrometastasis. 42 out of 44 patients (95.5%) in the OSNA cohort had an ALND in the same surgery (p = 0.03).


CONCLUSIONS
OSNA assay detects SLNs metastases as accurately as conventional pathology in the NAC setting. Intraoperative definitive assessment of the SLN by OSNA reduces the need for a second surgery for ALND in 18.5% of breast cancer patients with a positive-SLN after NAC.
Breast Surgical Unit, Breast Cancer Center, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Passeig de la Vall d'Hebron 119-129, 08035 Barcelona, Spain. Electronic address: maespino@vhebron.net.
Martin
M
Espinosa-Bravo
Breast Surgery Unit, Department of Surgery, Hospital Complex of Jaén, Av. del Ejército Español 10, 23007 Jaén, Spain. Electronic address: dr.jnavarro@hotmail.com.
Joaquin
J
Navarro-Cecilia
Department of Surgery, Breast Surgery Unit, Salamanca University Hospital, Paseo San Vicente 58-182, 37007 Salamanca, Spain. Electronic address: mramos@usal.es.
Manuel
M
Ramos Boyero
Breast Surgical Unit, Breast Cancer Center, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Passeig de la Vall d'Hebron 119-129, 08035 Barcelona, Spain. Electronic address: sdiazmd@gmail.com.
Sebastian
S
Diaz-Botero
Breast Surgery Unit, Department of Surgery, Hospital Complex of Jaén, Av. del Ejército Español 10, 23007 Jaén, Spain. Electronic address: bdr@quesadasolidaria.org.
Basilio
B
Dueñas Rodríguez
Department of Surgery, Hospital Complex of Jaén, Av. del Ejército Español 10, 23007 Jaén, Spain. Electronic address: caluque@gmail.com.
Carolina
C
Luque López
Department of Surgery, Breast Surgery Unit, Salamanca University Hospital, Paseo San Vicente 58-182, 37007 Salamanca, Spain. Electronic address: tramos@usal.es.
Teresa
T
Ramos Grande
Breast Oncology Unit, Salamanca University Hospital, Paseo San Vicente 58-182, 37007 Salamanca, Spain. Electronic address: rruanoperez@gmail.com.
Ricardo
R
Ruano Perez
Department of Pathology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Passeig de la Vall d'Hebron 119-129, 08035 Barcelona, Spain. Electronic address: vpeg@vhebron.net.
Vicente
V
Peg
Breast Surgical Unit, Breast Cancer Center, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Passeig de la Vall d'Hebron 119-129, 08035 Barcelona, Spain. Electronic address: irubio@vhio.net.
Isabel T
IT
Rubio
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D016022:Case-Control Studies; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D007432:Intraoperative Period; D008197:Lymph Node Excision; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D061206:Neoplasm Micrometastasis / Q000473:pathology; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012086:Reoperation; D000071036:Sentinel Lymph Node / Q000473:pathology* / Q000601:surgery; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D055815:Young Adult
D000970:Antineoplastic Agents
Breast cancer; Neoadjuvant chemotherapy; OSNA assay; Sentinel lymph node