The shared experience of adolescent and young adult cancer patients and their caregivers.

The AYA patients' and caregivers' illness perceptions are distinct from each other and from objective medical indicators of illness severity. Patients' reports of subjective illness severity may be a marker for their own and their caregivers' mental health. Patient care and efficacious psychosocial interventions may require consideration of both patients' and caregivers' subjective perceptions of illness severity.