The nature of the risks involved in adolescents and young adults’ substance use has evolved considerably in the 21st century. While there has been a decline in the use of some substances such as alcohol, and changes in how substances such as nicotine and cannabis are consumed, the overall increase in substance use in this population has been driven by new psychoactive substances and nitrous oxide (laughing gas). However, adolescents and young adults with cancer are often reluctant to discuss their substance use with healthcare professionals, who often lack the knowledge, skills and time to engage with this complex and continually changing area.

The authors undertook a narrative literature review on risk-taking behaviour involving substance use in adolescents and young adults, contextualising the main themes to adolescents and young adults with cancer. Healthcare professionals working with adolescents and young adults with cancer require improved evidence to understand the effect of substance use on treatment regimens, adherence to cancer therapy and the consequences for late effects. There is also a need for a wider appreciation of the effect that family, peers and social setting have on the nature and expression of substance use in this population.