PredictAYA is a multidisciplinary effort to fully address and improve the understanding of late effects in AYAs 15-39 years treated for cancer, by building on data from existing populations-based registers, large genomic biobanks and newly established clinical AYA cohorts. Importantly, the patient perspective will be captured in our clinical cohorts and patients’ care preferences and needs including the psychosocial impact of cancer treatment on reproductive health, sexuality and quality of life in AYAs. By cooperation between clinicians, researchers, psychologists, oncology nurses and with patient involvement, the study will use a participatory research approach and develop in co-creation with representative AYAs with cancer. This action is part of the Cancer Mission cluster of projects on “Quality of life (AYA). Our long-term goal is to develop a panel of validated biomarkers to identify individuals at high-risk of organ toxicities, aiming at clinical implementation and future individualized screening and counselling. Our main focus is on reproductive toxicity and through innovative precision medicine and pharmacogenetics, we will identify genetic biomarkers explanatory for interindividual variation in treatment induced toxicity among AYAs. A model on constitutional genetic risk for reproductive organ toxicity will be evaluated in clinical cohorts across Europe. Future precision-medicine applications and clinical implementation are envisaged as potential benefit of our proposal. Additional research questions include the prevalence, severity and timing of gonadal toxicity for different cancer treatments in both sexes, the timing and risks of pregnancy, the risk of accelerated aging, the health of the children born to AYAs. The safety and efficacy of fertility preservation methods will be investigated in detail. Our methodology will also allow us to investigate additional phenotypes and find associations among reproductive, endocrine, cardiac and neurologic toxicity, risk factors including social and health determinants and comorbidity patterns.