In an earlier study, the author found that the melanoma
incidence stayed fairly constant after 30 years of age
during the first part of the 20th century in several countries.
All birth cohorts, however, continued to show increasing
incidence from 1957 onwards, and also after the age of 30
years. Before 1957, cell damage in skin older than about 30
years thus did not seem to be able to generate melanoma,
whereas cell damage sustained later could pose a
melanoma risk for much longer durations.