The increase in the number of cancers depends on a number of parameters: demographic changes, notably in the age distribution of the population, and the progression of the incidence rate related to age, which itself depends not only on the true risk of having the disease, but also the risk of being diagnosed. All these parameters are riddled with uncertainties to such an extent that the projections are presented as scenarios. The demographic scenarios presented by the INSEE depend on three factors: fertility, mortality, and migrations. For the two extremes, they lead to an estimation of the population of France ranging from 61 to 79 million inhabitants, but none of the scenarios challenges the aging of the population up to 2050. As for the progression of cancer incidence, there are only medium-term projections. These are based on modeling the trends observed : an average trend over a long period or a recent trend, or finally stability maintaining the last incidence observed. These simulations do not take into account possible changes in the factors associated with risk.