In patients with oncological diseases in the reproductive phase of life, tumour therapy often leads to a reduction in fertility and possibly subsequent involuntary childlessness. Therefore, one of the research focuses of this subproject is on the significance of tumour- and therapy-associated changes in DNA integrity and DNA methylation for fertility in male patients as well as the determination of the diagnostic value of cell-free tumour DNA (ctDNA) and circulating tumour cells (CTCs). Due to the clinical relevance in the context of fertility preservation, the focus is on oncological diseases with typical manifestation in adolescence and young adulthood, in particular haematological neoplasms such as lymphomas, germ cell tumours and sarcomas.

• Technical establishment of assays for the detection of ctDNA and CTCs in blood and ejaculate in various tumour entities (haematological neoplasms such as lymphomas, germ cell tumours and sarcomas)
• Development of DNA methylation assays for ctDNA that are independent of the presence of individual tumour cell mutations
• Description of the dynamics of changes in DNA methylation patterns and, if applicable, DNA damage in blood and sperm
• Cross-sectional and longitudinal analyses of ejaculate samples from men with reduced fertility due to tumour diseases, treatment with cytotoxic therapies or cryopreservation
• Understanding the mechanisms of male infertility in the context of oncological diseases of the reproductive phase
• Clarification of the subsequent safety of the use of sperm samples from men with tumour diseases