Sentinel node mapping performed before preoperative chemotherapy may avoid axillary dissection in breast cancer patients with negative or micrometastatic sentinel nodes.
BACKGROUND
Sentinel node (SN) biopsy after preoperative chemotherapy (PC) in breast cancer patients is associated with a lower identification rate (IR) and an increased false-negative rate (FNR) compared with SN biopsy in untreated patients. Our aims were to examine the feasibility of SN mapping before PC and the possibility to assess the lymph node status after chemotherapy through a follow-up lymphatic mapping.


METHODS
SN biopsy was performed in 45 clinically node-negative breast cancer patients before PC. A follow-up lymphatic mapping was done after completion of chemotherapy and irrespective of the lymph node status was followed by axillary lymph node dissection (ALND).


RESULTS
SN mapping before chemotherapy identified a mean of 2.3 SNs in all patients (IR 100%). Nineteen patients revealed a negative SN; 26 patients had a positive SN (micrometastasis found in 6/26 patients). After PC follow-up lymphatic mapping was successful in 29 of 45 patients (IR 64%). IR for follow-up mapping was 80% for patients with a negative or micrometastatic SN before chemotherapy compared with 45% for patients with macrometastatic SNs (P = .027, Fisher exact test). None of the patients with a negative or micrometastatic SN before chemotherapy revealed positive lymph nodes after PC (P = .031, McNemar test) and the FNR for follow-up lymphatic mapping in these patients was 0%. Contrary to that, 15 of 20 patients with a macrometastasis before PC had positive nodes after chemotherapy, and the FNR of follow-up mapping in these patients was 50%.


CONCLUSIONS
Patients with a negative SN before PC may forego complete ALND after PC, whereas this may not be valid for patients with macrometastatic SNs. Follow-up lymphatic mapping in patients with positive nodal status before chemotherapy is associated with a low IR and a high FNR.
Schrenk
Peter
P
Second Department of Surgery, Ludwig Boltzmann Institute for Surgical Endoscopy, AKH Linz, Krankenhausstrasse 9, 4020 Linz, Austria. peter.schrenk@liwest.at
Tausch
Christoph
C
Wölfl
Soraya
S
Bogner
Stephan
S
Fridrik
Michael
M
Wayand
Wolfgang
W
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011300:Preoperative Care; D011877:Radionuclide Imaging; D021701:Sentinel Lymph Node Biopsy
D000970:Antineoplastic Agents