Epidermal growth factor receptor expression in high-grade osteosarcomas is associated with a good clinical outcome.
OBJECTIVE
The expression of the epidermal growth factor receptor (EGFR) in osteosarcomas has repeatedly been described. With the introduction of anti-EGFR-targeted therapies in clinical practice, these findings regain increased attention. Experience with anti-EGFR-targeted therapies in other cancers has made clear that besides the expression status of EGFR, a detailed knowledge about gene mutations is of major predictive power. We therefore aimed to explore the EGFR expression and gene mutation status in high-grade osteosarcomas.


METHODS
We investigated tumor samples of osteosarcoma patients of all age groups by means of immunohistochemistry (n=111) and egfr fluorescence in situ hybridization (n=39). Sixty-three patients were treated according to the Cooperative Osteosarcoma Study Group protocols and complete clinical follow-up was available in these cases.


RESULTS
Ninety-one of 111 (81%) of osteosarcomas revealed an expression of EGFR. EGFR expression showed a dose-response relation with improved event-free and overall survival. This was independent of the degree of tumor regression due to neoadjuvant chemotherapy. Nine of 39 (23%) osteosarcomas showed egfr amplifications by means of fluorescence in situ hybridization. All these cases expressed EGFR. When comparing EGFR expression between primary biopsy and resection specimen (n=19), viable residual tumor cells in resection specimens revealed a lower EGFR expression and a tendency toward membranous staining compared with the initial biopsy.


CONCLUSIONS
In conclusion, expression and amplification of EGFR are frequently observed in high-grade osteosarcomas and are associated with improved prognosis in a dose-responsive way. This implies that low EGFR expression possibly predicts lack of response to conventional treatment in high-grade osteosarcomas and may warrant a more intensive therapeutic approach, although not based on EGFR targeting.
Kersting
Christian
C
Institute of Pathology, University of Münster, Münster, Germany.
Gebert
Carsten
C
Agelopoulos
Konstantin
K
Schmidt
Hartmut
H
van Diest
Paul J
PJ
Juergens
Heribert
H
Winkelmann
Winfried
W
Kevric
Matthias
M
Gosheger
Georg
G
Brandt
Burkhard
B
Bielack
Stefan
S
Buerger
Horst
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality*; D011379:Prognosis; D013534:Survival
D066246:ErbB Receptors