LAUSR

The cumulative risk (CR) of developing cancer is a measure of the spread of cancer in a population used because it is intuitive to understand. However, there are various methods to calculate it leading to results with different interpretations. With real data we calculated the CR of developing any tumour in males and females to age 84 using three approaches. With the former, which uses only the cancer incidence, a CR to age 84 is estimated equal to 51.7% in males and 36% in females. With the second, which takes into account the competing risk of dying for other causes, the CR to age 84 is estimated equal to 44% in males and 32.9% in females. Finally, after adjusting for multiple primaries in the same person, the CR to age 84 boils down to 37.7% in males and 29.2% in females. Only methods taking into account the competing risk of dying for other causes and adjusting for multiple primaries in the same person are appropriate to estimate the real risk of developing any tumour in the course of life. For estimating the real risk of developing a specific form of cancer we must take into account the competing risk of dying while the adjustment for the occurrence of multiple primaries should be considered only for some long-survival sites. KEYWORDS: cumulative risk; cancer incidence; competing risks.