Fibroblast growth factor receptor 1 gene (FGFR1) amplification and prognosis relationship in serous ovarian tumors

Aim: The aim of this study was to evaluate the ovarian serous surface epithelial tumors in terms of FGFR1 expression and to evaluate the differences in expression of serous cystadenomas, borderline serous tumor//atipical proliferative serous tumors, low grade and high grade serous carcinomas. Materials and methods: A hundred patients diagnosed with serous cystadenomas, borderline serous tumor/atipical proliferative serous tumors, low grade and high grade serous carcinomas between 2010-2019 in our pathology laboratory were included in the study. Borderline tumors and LGSK's were examined in a single group, considering their genetic characteristics and case numbers. In these cases, FGFR1 expression was investigated by PCR and immunohistochemistry methods with sections taken from paraffin blocks. Results: In our study, it was determined that FGFR1 gene expression was statistically significantly increased in HGSK cases compared to the Borderline / LGSK group and the SC group. Although there was a difference between the borderline / LGSK group and the SC group, no statistical significance was found. Cytoplasmic and nuclear H scores were calculated for all cases in immunohistochemical staining. The mean cytoplasmic H scores were 202.03 for the HGSK group, 134.29 for the LGSK/Borderline group and 76.54 for the serous cystadenoma group. Conclusion: FGFR1 expression was significantly increased in HGSK cases. With PCR and immunohistochemistry, the groups are statistically significantly different from each other. In HGSK cases, FGFR1 fold change is high by PCR. In immunohistochemically, cytoplasmic H score shows a statistically significant increase in HGSC cases compared to other groups. Cytoplasmic H score was found to be statistically significantly higher in the LGSK / Borderline group compared to the SC group. Immunohistochemically, cytoplasmic H score correlated weakly with Ki-67 proliferation index, and no correlation was detected with p53, estrogen receptor and progesterone receptor.