Testicular cancer in nine northern european countries

TLDR

The study examined testicular cancer incidence across nine Northern European countries and highlighted the need for new aetiological hypotheses to explain the observed geographic and temporal patterns. Population‑based cancer registries from 10 countries were used to analyze 34,309 cases diagnosed between 1943 and 1989. The analysis revealed a ten‑fold geographic variation, with Denmark having the highest and Lithuania the lowest rates, and showed that incidence rose rapidly (≈2–5% per year) across all countries, especially among those under 30, peaking at ages 25–34, indicating strong early‑life environmental influences that double the age‑standardized incidence every 15–25 years.

Abstract

Abstract The incidence of testicular cancer was examined in the Nordic and Baltic countries, Poland and Germany by collaboration among 10 cancer registries. Population‐based registers were used to analyze a total of 34,309 cases, diagnosed from the start of registration (varying from 1943 in Denmark to 1980 in Latvia and Lithuania) through 1989. An approximately 10‐fold geographical variation was found in 1980, with the highest age‐standardized incidence rate (7.8 per 10 5 ; world standard population) in Denmark and the lowest (0.9) in Lithuania. During the entire period of registration, incidence increased rapidly in all countries, by 2.3 to 3.4 per cent annually in the Nordic countries and by about 5 per cent in Poland and Germany; there was some evidence of a slower increase in Denmark and Poland after 1975. The rising trend was more pronounced for ages below 30. The age‐specific incidence peaked in all countries at ages 25 to 34, but the geographical variation was considerable. Our data indicate that environmental influences on testicular cancer are strong. Exposure to causal factors mostly takes place early in life, shows substantial geographical variation, and increases over time, so that the age‐standardized incidence doubles every 15 to 25 years. New aetiological hypotheses are needed to accommodate these salient features of the descriptive epidemiology, since risk factors considered so far cannot explain the observed pattern.