Lymph node metastases displaying lower Ki-67 immunostaining activity than the primary breast cancer.
The aim of the study was to verify by Ki-67 immunostaining if any difference exists in the cell proliferating fraction between primary breast tumors (PTs) and matching positive axillary lymph nodes (ALNs).


METHODS
Immunohistochemistry with the monoclonal antibody against Ki-67 was performed in 160 node-positive breast carcinomas and in their respective lymph node metastases.


RESULTS
An increase of Ki-67 immunoreactive cells in ALN compared with that of PTs was observed in 84% of cases (ALN: mean 17%, PTs: mean 8%; p < 0.001), whereas 16% of the cases showed Ki-67 value two to six times lower in the ALNs than in the corresponding PTs (ALN: mean 3.2%, PTs mean 12.5%; p < 0.005). The decrease of Ki-67 positive cells in the ALN was independent from the histotype and the histological grade of the tumor.


CONCLUSIONS
A different cell proliferation fraction between PTs and matching positive ALNs was demonstrated and underlined that the existence of a group of patients with decreased number of Ki-67 immunoreactive cells in lymph node metastases compared with that of the primary tumors could be taken into account in the choice of therapeutic strategy.
Cabibi
D
D
Dipartimento di Patologia Umana Facoltà di Medicina e Chirurgia, Policlinico Universitario, 90127, Palermo, Italy.
Mustacchio
V
V
Martorana
A
A
Tripodo
C
C
Campione
M
M
Calascibetta
A
A
Sanguedolce
R
R
Aragona
F
F
D001943:Breast Neoplasms / Q000276:immunology*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000276:immunology*; D008207:Lymphatic Metastasis / Q000276:immunology*
D019394:Ki-67 Antigen