Numerical abnormalities of chromosome 7 in interphase cell nuclei of breast carcinoma have no impact on immunohistochemically determined EGFR status.
OBJECTIVE
To investigate the relationship between epidermal growth factor receptor (EGFR) status and numerical aberrations of chromosome 7 in breast carcinomas.


METHODS
In situ hybridization (ISH) of interphase cell nuclei on air-dried fine-needle aspirates (FNAC) from 33 breast carcinomas was evaluated for numerical abnormalities in chromosome 6, 7, 12 and 17. Immunohistochemical staining of EGFR was performed on corresponding histological specimens.


RESULTS
78% of the tumours were aneuploid by ISH. Aneusomy of chromosome 7 was found in 18 cases (60%). EGFR overexpression was observed in 30% of the carcinomas, and seven of nine were aneuploid by ISH. The same percentage of chromosome 7 aneusomy was found in both EGFR-positive and -negative cases. Five of seven EGFR-positive tumours revealed aneusomy of chromosome 7.


CONCLUSIONS
Numerical gain of chromosome 7 is a common finding, occurring in about 60% of breast carcinomas. Most EGFR-positive tumours are aneuploid and show numerical gain of chromosome 7, but abnormal numbers of chromosome 7 have no impact on the EGFR status.
Sauer
T
T
Department of Pathology, Ullevaal University Hospital, Oslo, Norway.
Beraki
K
K
Jebsen
P W
PW
Naess
O
O
D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D002897:Chromosomes, Human, Pair 7; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D007399:Interphase
D066246:ErbB Receptors