Her-2/neu oncogene amplification and protein over-expression in interval and screen-detected breast cancers.
BACKGROUND
Studies of Her-2/neu protein expression in interval and screen-detected breast cancers have been conflicting. Therefore we assessed the Her-2/neu amplification status in these groups by using in situ hybridization.


METHODS
The Her-2/neu oncogene amplification and protein over-expression were compared in 79 screen-detected and 39 interval breast carcinomas, using a novel and well-documented chromogenic in situ hybridization (CISH) method and immuhistochemistry.


RESULTS
There were 33% CISH-positive cases in the interval cancer group and only 4% CISH-positive cases in the screen-detected group. The odds ratio for interval cancer was 14.1 (95% CI 2.2 to 91.0) in the CISH-positive tumours compared with CISH-negative tumours after adjustment for nodal status, tumour size and histological grade.


CONCLUSIONS
Our results indicate, for the first time, that there is a clear-cut difference in Her-2/neu amplification between screen-detected and interval breast carcinomas. The amplification appears to be a rare event in screen-detected cancers but distinctly frequent in interval cancers when compared to cancers described in earlier studies.
Anttinen
Jorma
J
Department of Pathology, Jyväskylä Central Hospital, Keskussairaalantie 19, 40620 Jyväskylä, Finland. Jorma.Anttinen@ksshp.fi
Kuopio
Teijo
T
Nykanen
Marjukka
M
Torkkeli
Helena
H
Saari
Urpo
U
Juhola
Matti
M
D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics
D018719:Erb-b2 Receptor Tyrosine Kinases