Cognitive Impairment in Survivors of Adolescent and Early Young Adult Onset Non-CNS Cancers: Does Chemotherapy Play a Role?

INTRODUCTION: The development of complex cognitive functions including executive functions occurs during adolescence and early young adulthood. Survivors of cancers diagnosed during adolescence and young adulthood (AYA) may be at specific risk for chemotherapy-associated cognitive impairment; however, little data are available that specifically examine long-term cognitive outcomes in the AYA-onset cancer survivor population.
METHODS: A literature search was conducted between January 1991 to December 2015 using a variety of search terms pertaining to the AYA-onset cancer population and cognitive outcomes. Articles that described cognitive outcomes in AYA-onset cancer survivors without primary or secondary central nervous system lesions diagnosed at ages 14-25 years old were examined and reported.
RESULTS: Three articles fulfilled the inclusion criteria. All three evaluated cognitive outcomes in AYA-onset cancer survivors at varying time points after receipt of systemic chemotherapy. Target groups and neuropsychological evaluation techniques differ across studies. All studies reported increased rates of objective or self-reported cognitive impairment in AYA-onset cancer survivors. DISCUSSION: AYA-onset cancer survivors experience cognitive impairment. Despite the nature of normal adolescent neurodevelopment, chemotherapy exposure during the AYA years may not significantly contribute to cognitive impairment. Chronic cognitive impairment may be associated with chronic complications of cancer therapy. Large-scale standardized, prospective, and longitudinal evaluations of cognitive outcomes specific to AYA-onset cancer survivor population are needed to better understand associated risk factors.