A Developmental Science Approach to Informing Age Subgroups in Adolescent and Young Adult Cancer Research

Abstract

Purpose: Adolescent and young adult (AYA; diagnosed ages 15-39) cancer survivors are developmentally heterogenous, and this population consists of at least three distinct theoretically informed subgroups, as follows: adolescents, emerging adults, and young adults. However, there are limited evidence-based recommendations for delineating the validity of these subgroups in cancer-specific research. We sought to inform recommended chronological age ranges for each subgroup based on developmental processes.

Methods: The data were collected using a 2x3 stratified sampling design (on-vs. off-treatment; ages 15-17, 18-25, 26-39) and a cross-sectional survey. AYAs (N = 572) completed three subscales of the Inventory of Dimensions of Emerging Adulthood (identity exploration, experimentation/possibilities, and other-focused), and we used regression tree analyses to identify distinct shifts in mean subscale scores that would indicate unique subgroups. Models included (a) chronological age, (b) chronological age + cancer-related variables, and (c) chronological age + sociodemographic/psychosocial variables as predictors of each developmental measure.

Results: The recommended age ranges for AYA survivors receiving active treatment were consistent with prior research as follows: adolescents ages 15-17, emerging adults ages 18-24, and young adults ages 25-39. Models for off-treatment survivors suggested four distinct subgroups: adolescents ages 15-17, emerging adults ages 18-23, and 'younger' (ages 24-32) and 'older' young adults (ages 33-39). No sociodemographic or psychosocial variables meaningfully shifted these recommendations.

Discussion: Our results suggest that three developmental subgroups remain appropriate for on-treatment survivors, but a second young adult subgroup (ages 33-39) emerged for off-treatment survivors. Therefore, development disruptions may be more likely to occur or manifest in post-treatment survivorship.

Keywords: adolescent and young adult; cancer; development; developmental science.