ORIGINAL ARTICLE

c-KIT and PDGFRA in breast phyllodes tumours: overexpression without mutations?

S Carvalho¹, A O e Silva², F Milanezi³, S Ricardo¹, D Leitão¹, I Amendoeira² and F C Schmitt⁴

¹ IPATIMUP, Institute of Molecular Pathology and Immunology of Porto University, 4200 Porto, Portugal
² IPATIMUP, Hospital São João, Medical Faculty of Porto University, 4200 Porto, Portugal
³ IPATIMUP, School of Health Sciences, University of Minho, 4710-057 Braga, Portugal
⁴ IPATIMUP, Medical Faculty of Porto University

Correspondence to:
Correspondence to:
Dr F Schmitt
Institute of Molecular Pathology and Immunology, University of Porto, R. Dr Roberto Frias s/n, 4200 Porto, Portugal; fernando.schmitt{at}ipatimup.pt

Aim: To study the immunoexpression and mutational status of c-KIT and PDGFRA in a series of benign and malignant phyllodes tumours of the breast.

Material/methods: Nineteen phyllodes tumours (13 benign and six malignant) were analysed by immunohistochemistry for the expression of c-KIT and PDGFRA. Direct sequencing of exons 9, 11, 13, and 17 of the c-KIT gene and exons 12 and 18 of PDGFRA was performed to check the mutational status of these two genes.

Results: c-KIT expression was found in 12 of the 19 cases (six of the 13 benign cases and all six malignant ones) and PDGFRA expression was seen in two of the 19 cases (one benign and one malignant case); the 2415 C>T alteration in exon 17 of the c-KIT gene was found in two cases (both benign); the intronic insertion IVS17-50insT and the 2866 G>T alteration in the coding region of exon 18 of the PDGFRA gene were also found in two cases (one malignant and one benign). However, the activating mutations described for these genes in gastrointestinal stromal tumours were not present.

Conclusion: c-KIT expression is a frequent finding in phyllodes tumours, particularly in malignant cases; however, no activating mutations similar to those described for gastrointestinal stromal tumours were found. The PDGFRA does not seem to be an alternative pathway to tumour development in phyllodes tumours because neither expression nor activating mutations were noteworthy.

Abbreviations: GIST, gastrointestinal stromal tumour; PCR, polymerase chain reaction; PDGFRA, platelet derived growth factor receptor A

Keywords: phyllodes tumours; gastrointestinal stromal tumours; c-KIT; PDGFRA

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Huynh, H., Lee, J. W.J., Chow, P. K.H., Ngo, V. C., Lew, G. B., Lam, I. W.L., Ong, H. S., Chung, A., Soo, K. C. (2009). Sorafenib induces growth suppression in mouse models of gastrointestinal stromal tumor. Molecular Cancer Therapeutics 8: 152-159 [Abstract] [Full Text]  
• Burstein, H. J., Elias, A. D., Rugo, H. S., Cobleigh, M. A., Wolff, A. C., Eisenberg, P. D., Lehman, M., Adams, B. J., Bello, C. L., DePrimo, S. E., Baum, C. M., Miller, K. D. (2008). Phase II Study of Sunitinib Malate, an Oral Multitargeted Tyrosine Kinase Inhibitor, in Patients With Metastatic Breast Cancer Previously Treated With an Anthracycline and a Taxane. JCO 26: 1810-1816 [Abstract] [Full Text]