Cancer trends in England in younger adults from 2001-2023: comparing incidence, mortality and stage at diagnosis.

Objectives: To compare trends in incidence and mortality rates for cancers with rising incidence in younger adults in England, and to assess whether increasing incidence is observed for early-stage, late-stage or both types of disease. Methods and analysis: We used cancer incidence and mortality data from English National Disease Registration Service (2001-2023). Analyses focused on 12 cancers with increasing incidence (on average) in younger adults (20-49 years) and more than 500 cases diagnosed in 2023. Trends were quantified by estimating the average annual percentage changes (AAPCs) and 95% confidence intervals (CI) using Joinpoint regression and by calculating the excess number of cancer cases in 2023 compared to 2001. Age-standardised rates (ASRs) of early (stage 1-2) and late-stage (stage 3-4) disease were compared between 2013 (the earliest year available) to 2023. Results: There were 31,385 cancers diagnosed in younger adults in 2023 compared to 244,384 in older adults. The most common cancers diagnosed in younger adults were female breast (n=8,504), colorectal (n=2,977) and melanoma (n=2,767). Of the 12 cancers that were increasing in younger adults between 2001 and 2023, only two also had increasing mortality rates: endometrial (AAPC[95%CI]= incidence 2.9%[2.4-3.4%] and mortality 4.0%[2.1-6.0%]) and colorectal cancer (AAPC[95%CI]= incidence 3.2%[2.8-3.6%] and mortality 1.9%[1.1-2.7%]). For thyroid cancer mortality rates were stable and for the other cancers (female breast, testicular, ovarian, kidney, brain, prostate, Hodgkin lymphoma and leukaemia) although incidence rates were increasing, mortality rates were decreasing, on average. Of the ten cancers with available stage data six showed increases in incidence rates for both early and late-stage disease between 2013 and 2023. Four cancers showed increases only in late-stage disease (female breast, ovarian, melanoma and Hodgkin lymphoma), while thyroid cancer showed an increase only in early-stage disease. Conclusions: These population-wide analyses of national data from England, combining cancer incidence, mortality and stage-stratified incidence trends, highlight several public health and research priorities. These include identifying the causes of increasing colorectal cancer incidence in younger adults, given the marked increases in mortality and late-stage disease, and of increasing breast cancer incidence, which affects the largest number of younger adults and is increasing only for late-stage disease.