RECENT INCREASE IN THE INCIDENCE OF NON-HODGKINS-LYMPHOMA AMONG YOUNGMEN AND WOMEN IN DENMARK

Time-related trends in the incidence of non-Hodgkin's lymphoma (NHL) i n Denmark were analysed for the period 1943-89. A total of 13 822 pati ents (7565 men and 6257 women) were included in the study. In men, wor ld-standardised incidence rates per 100 000 population increased from 2.5 in 1943-47 to 9.3 in 1988-89. In women, a similar increase was see n, i.e. from 1.9 in 1943-47 to 6.5 per 100 000 population in 1988-89. For all birth cohorts, the male-to-female incidence ratio was highest among young subjects and fell significantly after the age of 29 years. Trends in age-specific incidence were analysed separately for two per iods, i.e. 1943-77 and 1978-89, reflecting an early, pre-AIDS period a nd a later period possibly influenced by AIDS. In both periods, the in cidence of NHL, increased in all age groups. However, in recent years a noticeable increase in incidence averaging 8% annually was observed in men and women aged 40-49 years. A number of factors including chang es in the perception of NHL and in the diagnostic methods available ar e considered insufficient to explain the observed increase. The remark able and parallel time trends observed in young men and women in recen t years indicate that factors other than AIDS must be considered.