Incidence, Survival, and Mortality Trends of Cancers Diagnosed in Adolescents and Young Adults (15-39 Years): A Population-Based Study in The Netherlands 1990-2016

Simple Summary Adolescents and young adults (AYAs, aged 15-39 years) with cancer form a distinct patient population within the oncology care setting that is often overlooked in favour of paediatric and older adult patients. As such, specific knowledge on AYAs and their distinct spectrum of cancers is limited. Worldwide, cancer is increasing and it is among the major causes of death among AYAs. Cancer prognosis among AYAs has also been shown to lag behind that of younger and older patients suffering from similar diseases. To address these problems, better understanding of AYA cancers is needed. This study aims to provide an overview of the specific cancer trends among AYAs and the changes that have occurred in the Netherlands since 1990 in terms of incidence, survival, and mortality. This information will provide a solid foundation from which to guide future studies upon, aimed at acquiring more detailed cancer knowledge within the AYA domain. Adolescent and young adult (AYA) cancer patients, aged 15-39 years at primary cancer diagnosis, form a distinct, understudied, and underserved group in cancer care. This study aimed to assess long-term trends in incidence, survival, and mortality of AYA cancer patients within the Netherlands. Data on all malignant AYA tumours diagnosed between 1990-2016 (n = 95,228) were obtained from the Netherlands Cancer Registry. European age-standardised incidence and mortality rates with average annual percentage change (AAPC) statistics and five-year relative survival rates were calculated. The overall cancer incidence increased from 54.6 to 70.3 per 100,000 person-years (AAPC: +1.37%) between 1990-2016, and increased for both sexes individually and for most cancer types. Five-year relative survival overall improved from 73.7% in 1990-1999 to 86.4% in 2010-2016 and improved for both sexes and most cancer types. Survival remained poor (<60%) for rhabdomyosarcoma, lung, stomach, liver, bladder, and pancreatic carcinomas, among others. Mortality rates among male AYAs overall declined from 10.8 to 6.6 (AAPC: -1.64%) and from 14.4 to 10.1 per 100,000 person-years (AAPC: -1.81%) for female AYAs since 1990. Mortality rates remained unchanged for male AYAs aged 20-24 and 25-29 years. In conclusion, over the past three decades, there has been a considerable increase in cancer incidence among AYAs in the Netherlands. Meanwhile, the survival improved and the mortality overall declined. Survival at five-years now well exceeds above 80%, but did not do so for all cancer types.