PO-360 Epigenetic changes in testicular cancer survivors treated with cisplatin

IntroductionTesticular germ cell cancer, hereafter called testicular cancer (TC), is the most common malignancy in young men in lagre parts of the world. Cisplatin-based chemotherapy (CBCT) has contributed to an increase in TC survival rates over the last decades. However, cisplatin exposure has been shown to result in drug-induced DNA hypermethylation. The aim of the present study is to study the effects of CBCT on DNA methylation in cisplatin-treated vs untreated TC survivors.Material and methodsWe included 279 Norwegian TC survivors, where 103 underwent orchiectomy, and 176 orchiectomy and additional CBCT. The two groups were matched on age at blood sampling. The TC survivors were re-examined on average 16 years after the orchiectomy. Whole genome DNA methylation profiles were measured with Illumina`s MethylationEPIC BeadChip and analysed with the R package minfi. We used a linear regression model adjusting for smoking, age and cell type composition to identify CBCT differentially methylated CpG sites. Additionally, genes with p-value