Research Questions:
1) Is chronic pain associated with mortality, life expectancy, depression, and anxiety in adolescent and young adult cancer survivors (AYA-CS)?
2) Do depression and anxiety mediate the association between chronic pain and mortality in AYA-CS?
3) Do blood inflammatory markers and brain regional volumes mediate the association of chronic pain with depression and anxiety in AYA-CS?
Objectives:
1) To quantify the association of chronic pain with mortality, life expectancy, depression, and anxiety among AYA-CS.
2) To explore the mediating effects of depression and anxiety in the association between chronic pain and mortality among AYA-CS.
3) To explore the mediating effects of blood inflammatory markers and brain regional volumes in the association of chronic pain with depression and anxiety among AYA-CS.
Scientific rationale:
Each year, over 1.2 million adolescents and young adults (AYAs) aged 15-39 are diagnosed with cancer globally. Over 80% of AYA-CS are expected to survive beyond 5 years, becoming long-term cancer survivors (CS). However, AYA-CS are at high risk for cancer-related late effects. Chronic pain is experienced by 35% of long-term CS, causing impaired quality of life. It is uncertain whether chronic pain relates to mortality and life expectancy in AYA-CS. Depression and anxiety are leading causes of disability worldwide, experienced by 29% and 24% of AYA-CS, respectively. It remains uncertain whether depression and anxiety are linked to chronic pain among AYA-CS and, furthermore, whether they mediate the association between chronic pain and mortality. In addition, alterations in brain regions responsible for pain processing may contribute to depression and anxiety, and blood inflammatory markers partially mediate depression risk in patients with chronic pain. However, these mechanisms remain underrecognized in AYA-CS and warrant further investigation.