Nodal-stage classification in invasive lobular breast carcinoma: influence of different interpretations of the pTNM classification.
PURPOSE Application of current nodal status classification is complicated in lobular breast carcinoma metastases. The aim of this study was to define the optimal interpretation of the pTNM classification in sentinel node (SN) -positive patients to select patients with limited or with a high risk of non-SN involvement. PATIENTS AND METHODS SN metastases of 392 patients with lobular breast carcinoma were reclassified according to interpretations of the European Working Group for Breast Screening Pathology (EWGBSP) and guidelines by Turner et al, and the predictive power for non-SN involvement was assessed. Results Reclassification according to definitions of EWGBSP and Turner et al resulted in different pN classification in 73 patients (19%). The rate of non-SN involvement in the 40 patients with isolated tumor cells according to Turner et al and with micrometastases according to EWGBSP was 20%, which is comparable to the established rate for micrometastases. The rate of non-SN involvement in the 29 patients with micrometastases according to Turner et al and with macrometastases according to EWGBSP was 48%, which is comparable to the established rate for macrometastases. Therefore, the EWGBSP method to classify SN tumor load better reflected the risk of non-SN involvement than the Turner et al system. CONCLUSION Compared with the guidelines by Turner et al, the EWGBSP definitions better reflect SN metastatic tumor load and allow better differentiation between patients with lobular breast carcinoma who have a limited or a high risk of non-SN metastases. Therefore, we suggest using the EWGBSP definitions in these patients to select high-risk patients who may benefit from additional local and/or systemic therapy.
van Deurzen
Carolien H M
CH
University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, the Netherlands.
Cserni
Gabor
G
Bianchi
Simonetta
S
Vezzosi
Vania
V
Arisio
Riccardo
R
Wesseling
Jelle
J
Asslaber
Martin
M
Foschini
Maria P
MP
Sapino
Anna
A
Castellano
Isabella
I
Callagy
Grace
G
Faverly
Daniel
D
Martin-Martinez
Maria-Dolores
MD
Quinn
Cecily
C
Amendoeira
Isabel
I
Kulka
Janina
J
Reiner-Concin
Angelika
A
Cordoba
Alicia
A
Seldenrijk
Cornelis A
CA
van Diest
Paul J
PJ
D001943:Breast Neoplasms / Q000145:classification* / Q000473:pathology / Q000628:therapy; D018275:Carcinoma, Lobular / Q000145:classification* / Q000556:secondary / Q000628:therapy; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate