Time trends of cancer incidence in young adults (20-49 years) in Italy. A population - based study, 2008-2017

To evaluate short-term (2008-2017) cancer incidence trends in Italy for individuals aged 20-49 years by sex and cancer type.

Observational study from population-based data collected by 20 Italian Cancer Registries, covering 33% of the Italian population. The age-standardized incidence rates (ASRs), overall and stratified by area, sex, cancer site or type, and major age groups (i.e., 20-39, 40-49), were computed.

In 2008-2017, cancer incidence rates were almost two times higher in Italian women aged 20-49 than in age-corresponding men (202.2 vs 112.4 per 100,000) on account of elevated rates of breast and thyroid cancers. Contrasting trends emerged according to cancer sites/types. ASRs for female breast cancer increased steadily from 2008 (82.4) to 2014 (86.2) and remained unchanged thereafter (i.e., 86.5 in 2017). During the study period, there was an increase for testicular cancer, skin melanoma in both sexes, and thyroid cancer until 2013 (followed by a slight decrease from 2014 to 2017). Conversely, ASRs consistently declined for colorectal cancer and were substantially stable or slightly decreasing for cervix uteri (from 8.1 to 7.7), ovary (from 7.5 to 6.9) and non-Hodgkin lymphoma (from 8.3 to 7.6 in men and from 5.9 to 5.5 in women).

Study findings do not support a unique temporal pattern for the incidence of early-onset cancer in Italy until 2017, as reported in other countries. Increases in incidence documented in both sexes for some tumor sites was counterbalanced by a decrease in other sites. The importance of supporting prevention strategies from the youngest of ages must be emphasized, and the role of anticipated screening should be carefully addressed.