Temporal Patterns of Cancer Incidence and Mortality in Italy: Cohort Effects and Young-Adult Trends

Background Over the past decades, cancer mortality has declined in many high-income countries owing to reductions in exposure to tobacco and other risk factors, screening programs, and advances in diagnosis and treatment. However, ongoing changes in environmental, behavioral, and metabolic risk factors continue to reshape the epidemiology of cancer. Objectives To provide a comprehensive assessment of long-term cancer incidence and mortality trends in Italy and investigate cohort patterns through age-period-cohort (APC) analyses. Methods We used certified mortality data for the period 1980-2023 from the World Health Organization and the Italian National Institute of Statistics databases, incidence data for 1995-2018 from the European Cancer Information System. We computed age-standardized mortality rates (ASMRs) and age-standardized incidence rates (ASIRs) using the Segi-Doll world standard population. We described long-term trends using locally estimated scatterplot smoothing (LOESS) regression. We quantified overall percentage changes between 2023-2010 for mortality and between 2018-2008 for incidence, with 95% confidence intervals (CI) derived from a parametric bootstrap assuming Poisson-distributed counts. We performed APC analyses using generalized additive models with a quasi-Poisson specification. Age, period, and cohort effects were modeled using cubic regression splines, allowing flexible estimation of nonlinear temporal patterns while addressing the identifiability problem inherent to APC models. Results Between 2010 and 2023, overall mortality declined by 25.5% (95%CI: -26.3%; -24.6%) in males (to 103.5/100,000) and 13.9% (95%CI: -14.9%; -12.7%) in females (to 71.4/100,000), with major reductions for stomach (~35%), lung (~30%) (except for a 15.4% increase in females aged 50+), and colorectal cancers (~33%). Mortality increased for testicular (8.3%), uterine (2.8%), and pancreatic cancer in both sexes (2.0% males, 6.9% females). Among young adults (25-49 years), mortality from all cancers declined by 22.1% (95%CI: -26.5%; -17.6%) in males and 19.2% (95%CI: -23.2%; -14.9%) in females but increased in testicular (36.6%), and uterine cancer (16.6%). In this age group pancreatic cancer decreased by 21.1%, whereas it remained stable in males (2.0%). APC analyses showed declining cohort-specific risks for most cancers among cohorts born after approximately 1925. Pancreatic cancer exhibited largely stable cohort risks, whereas female lung cancer risk increased up to the 1960 birth cohort before declining in more recent generations. Between 2008 and 2018, overall cancer incidence decreased by 10.9% (95%CI: -11.8%; -10.0%) in males (to 305.7/100,000) but increased by 2.9% (95%CI: 2.0%; 4.1%) in females (to 273.7/100,000), with rising trends for skin (~70%), thyroid (~25%), testicular (24.2%), and lung cancer in females aged 50+ (27.2%). Rates were stable for pancreatic cancer (0.3% in males, 6.7% in females) and increased modestly for breast cancer (3.9%). Among young adults, incidence increased in both males by (3.6%, 95%CI: -0.4%; 7.7%) and females (10.3%, 95%CI: 7.0%; 13.3%). Conclusions Cancer mortality in Italy has declined substantially over recent decades, reflecting the combined effects of smoking cessation in men, screening, and therapeutic advances. Nevertheless, less favorable trends persist for selected cancers, particularly pancreatic cancer and lung cancer among older women. The increasing incidence of cancers associated with metabolic, environmental, and lifestyle-related factors highlights emerging public health challenges.