Cancer Incidence Projections To 2035 In Northern Ireland

DONNELLY D. ²

Introduction
Monitoring trends in cancer incidence is essential for high quality cancer services. With incidence rates of many cancers increasing and the size of the elderly population expected to rise, projections of cancer incidence up to 2035 are presented to help guide future allocation of health service resources.

Methods
Age-specific rates for all cancers combined and 30 common cancers are determined for both sexes by year of diagnosis. The data is fitted separately for ages 0-49, 50-59, 60-69, 70-79 and 80+ using a generalised linear model with a power 5 link function. Five-year age group, five-year birth cohort and year of diagnosis are used as predictor variables. The resulting model is used to predict rates in future years, which are combined with population projections to provide estimates of the future number of cases.

Results
For all cancers (excluding non-melanoma skin) age-standardised rates are expected to fall by 1% by 2035 among males and rise among females by 13%. The number of cases is projected to increase by 25% among males and by 24% among females by 2020, while by 2035 increases of 65% for males and 63% for females are expected. Rates are projected to fall for male lung, bladder, brain, cervical, prostate, ovary and stomach cancers and leukaemia. Increases are expected for breast, colorectal, kidney, liver, oral, female lung, female pancreatic and uterine cancers, melanoma and non-Hodgkin's lymphoma. The number of cases is expected to increase for all cancer types except for cervical and stomach cancers.

Conclusion
This work monitors past changes to cancer cases and rates and predicts an increase of new cancer cases which will require preparation by service planners to meet the needs of future cancer patients. The potential exists to alter these projections through tobacco and alcohol control.