Leukaemia.

The most striking and consistent trend in leukaemia in different countries since 1950 is the recent decline in mortality in childhood, reflecting the advent of effective methods of treatment in the 1960s. Increases at ages 75-84 in several countries since 1950 are consistent with improvements in cancer registration and in the detail of death certification. However, in the main, these have not persisted into the 1980s. Otherwise, there has been no obvious international pattern, and partly for this reason, the rates have been presented in some detail so that readers can make their own judgment.