HER-2/neu and p27^Kip1 in progression of Fallopian tube carcinoma: An immunohistochemical and array comparative genomic hybridization study

Aims: To determine expression of p53, HER-2/neu and p27^Kip1 in serous Fallopian tube carcinoma (FTC) in relation to stage and grade, and to investigate DNA copy number changes of HER-2 and P27KIP1 as a potential mechanism of altered expression status. Methods and results: Immunohistochemistry was performed on 28 serous FTCs and 10 normal Fallopian tubes. p53 protein accumulated and p27^Kip1 was down-regulated significantly in early-stage FTCs compared with normal Fallopian tubes. HER-2/neu overexpression was absent in normal Fallopian tubes and in all stage I FTCs (n = 6) but present in 57% (12/21) of advanced-stage FTCs. No differences in expression between grade 2 and 3 tumours were detected. HER-2 gain/amplification was found by array comparative genomic hybridization in 23% (3/13) of analysed FTCs and all showed overexpression. HER-2/neu overexpression also occurred without DNA copy number changes in three other cases. For p27 ^Kip1, expression and DNA copy number were unrelated. Conclusions: p53 accumulation and p27^Kip1 down-regulation seem to be early events in Fallopian tube carcinogenesis. HER-2/neu showed overexpression, caused by gain/amplification in 50%, and may be involved in progression of FTC. These data contribute to a better understanding of the molecular carcinogenesis of FTC and to possible new therapeutic approaches.