A report published by the National Cancer Registry today shows that the number of cases of cancer could double by 2045 if current rates continue into the future. However, the overall increase could be a more modest 50% increase in both sexes if recent trends, including declines, in some cancers continue.

• This is the fourth set of projections produced by the National Cancer Registry (following on from reports in 2006, 2008 and 2014) aimed at ensuring that up to date estimates are available to allow for future planning of cancer services in Ireland.
• Projected increases in the size and average age of the Irish population in Ireland over the next 30 years have significant implications for the number of cases of cancer, as cancer is predominantly a disease of the elderly. The number of cancer cases has been projected up to 2045 using a number of different methods.
• For all cancers combined (excluding non-melanoma skin cancer), the simplest approach – a  “demography-only” model – projects a 111% increase for males and an 80% increase for females between 2015 and 2045, or a doubling of numbers overall to 43,000. This assumes that average rates of cancer during 2011-2015 apply in the future, and that changes in numbers of cases are due only to changes in population size and age.
• A fuller range of models has also been used to estimate the number of cases of cancer over coming decades. On average (using the median, or middle point, of all models including the demography-only model), these again project almost a doubling of female cases (an 84% increase by 2045), but a much more modest increase for males (18% by 2045) - about a 50% increase overall. This smaller overall increase (compared with the demography-only model) is because the more complex models take recent or long-term trends into account – thus, if the cancer rate (or individual risk) is declining, as is the case for male cancers as a whole, continuation of these trends would result in smaller increases in case numbers than population change alone would suggest.
• Using the “demography only” method, Hodgkin lymphoma had the smallest projected increases to 2045 for both males and females (41% and 34% respectively) and bladder cancer had the largest projected increase (147% and 138% respectively). Using the median of all models, the range of projections was much wider, with increases in case numbers ranging from 0% for prostate cancer (in males) and 38% for bladder cancer (in females) to 274% for cancer of the liver, gallbladder and biliary tract for males and 233% for females.
• In 2015, the cancers (excluding non-melanoma skin cancer) with the highest number of cases were prostate (3,214), female breast (3,106), lung (2,486), and colon (1,797).  The “demography only” method projects large increases for each of these major sites, with the order remaining almost unchanged: increases of 114% for prostate cancer to 6,870 cases; 119% for lung cancer to 5,450 cases; 63% for female breast cancer to 5,050 cases; and 112% for colon cancer to 3,810 cases. The median-model approach projects more modest increases for some of major sites, as well as changes to the order: increases of 132% for lung cancer to 5,760 cases; 50% for female breast cancer to 4,650 cases; 123% for colon cancer to 4,000; but no change in the number of prostate cancer cases.
• Preliminary estimates of the future numbers of cancer patients requiring cancer-directed treatment (surgery, radiotherapy or chemotherapy) are also presented. If cancer rates and treatment percentages remain unchanged (compared with 2011-2015), numbers of newly diagnosed patients undergoing treatment are projected to increase by 75% for surgery (from about 10,600 to 18,600), 77% for radiotherapy (from 7,200 to 12,800) and 68% for chemotherapy (from 6,800 to 11,500) between 2015 and 2045. A fuller analysis of the cost implications of treating growing numbers of cancer cases will be presented in a separate report later this year.