Rationale: Adolescent and young adult (AYA) cancer survivors, diagnosed between 18-39 years, much more than children, suffer from delay in diagnosis, lack of centralization of care, age-adjusted expertise and follow-up care. The distribution of tumor types, biology, risk factors, developmental challenges and treatment regimens are different in AYAs compared to children. Therefore findings derived from childhood cancer survivors cannot be extrapolated to AYAs. Likewise, several large tumor-specific cohort studies exist that do not specifically address unique AYA age-specific issues. Globally, so far, the identification of AYA patient subgroups that might be more susceptible to poor health outcomes has not been systematically addressed. The role of sociodemographic and treatment-associated risks, external exposures (e.g. lifestyle) and host factors (e.g. genetic); or combinations of influences for impaired (age-specific) health outcomes, remains largely unknown. Understanding who is at risk and why, will support the development of evidence-based AYA prevention, treatment and supportive care programs and guidelines.

Objective: To examine the prevalence, risk factors and mechanisms of impaired health outcomes (health-related quality of life and late effects) among a population-based sample of AYA cancer survivors. Study design: Retrospective, population-based, observational cohort study.

Study population: AYA cancer survivors, diagnosed at age 18-39 years between 1999-2015, identified from the Netherlands Cancer Registry (NCR), and alive 5-20 year after diagnosis Main study parameters/endpoints: Health-related quality of life; late effects

Inclusion Criteria:

• Pathological confirmed cancer diagnosis;
• Age 18 - 39 years at time of first cancer diagnosis;
• Provide written informed consent.
• Treated in an Academic hospital or Netherlands Cancer Institute

All AYA cancer patients, diagnosed at age 18-39 years and treated in one of the participating hospitals