Estimating cure and risk of death from other causes of adolescent and young adult cancer patients in Europe

Abstract

Background: Adolescents and young adults (AYAs), aged 15-39, face unique challenges as cancer survivors, including long-term health issues treatment. This study applies a novel approach to estimate the relative risk (RR) of mortality from non-cancer causes in AYA cancer patients compared to the general population and the cure fraction (CF) for AYA patients.

Methods: Conventional and new mixture cure models with various parametric survival functions were applied to the most common AYA cancers. EUROCARE-6 cases diagnosed between 1998 and 2002, with follow-up to 2014, were selected. Qualitative and quantitative criteria were used to select the optimal model. CFs and RRs were estimated by cancer type, age group, and sex.

Findings: RRs> 1 were found in both sexes for leukaemia, chronic myeloid leukaemia, lymphoma, central nervous system (CNS) tumours, and skin melanoma, and for testicular germ cell, breast and cervix cancers, with RR generally higher in younger patients and decreasing with age. For acute myeloid leukaemia, colorectal cancer, bone sarcoma for both sexes and soft tissue sarcoma, acute lymphoblastic leukaemia (ALL), and ovary germ cell in females, there was no indication for extra risk. Higher CFs were found in adolescents compared to older AYAs (30-39 years), especially for ALL, CNS tumours in males, and colorectal cancer in females.

Conclusion: Further studies are needed to understand why RRs are elevated in AYA patients, to investigate comorbidities and side effects of treatment. Accurate estimation of cancer mortality and CF is vital for resource allocation, tailored follow-up care, and imporving patient quality of life.

Keywords: Adolescent and young adults; Cure fraction; Mixture cure models; Population-based cancer registry; Relative risk of mortality from non-cancer causes.