Risk factors behind the increase of early-onset cancer in Italian adolescents and young adults: An investigation from the Italian AYA Working group

: The incidence of early-onset cancers in adolescents and young adults (AYA) has been increasing worldwide since the 1990s. In Italy, a significant increased rate of 1.6 % per year has been reported for early-onset cancers among females between 2008 and 2016. This is mainly attributable to melanoma, thyroid, breast and endometrial cancer. The aim of our work was to describe temporal trends of the main established lifestyle risk factors (tobacco use, alcohol consumption, obesity, physical inactivity, dietary westernization and reproductive factors) over the last 20 years in the Italian AYA population. Available data on behavioural risk factors, individual and household daily life have been obtained and elaborated from PASSI, ISTAT and Eurostat reports. Lowering age of smoking initiation, an increase in alcohol drinkers among young females, and an obesity and overweight epidemic, particularly among children and adolescents as a result of physical inactivity and dietary habits, may be contributing factors behind this cancer epidemic, especially among females. In-depth investigations are needed to understand the exact role of each contributing factor, the effects of exposure to nicotine-containing products and environmental factors such as endocrine disruptors that could play a role in this phenomenon.