V 100Eye melanoma in Finland: Time trends and relative survival rates
A. Stang, T. Hakulinen
Background: The Finnish Cancer Registry has been shown to be reliable and virtually complete since 1953 and therefore offers the opportunity to analyze representative population-based data for eye melamoma over a long time period.
Methods: We included 1752 patients with newly diagnosed eye melanoma during the period 1953-97 in Finland (population at risk: about 5.1 million). Incidence rates were age-standardized using the world standard population. We calculated annual and 5-year cumulative relative survival rates. The impact of sex, age at diagnosis, period of diagnosis and length of follow-up was assessed by regression modelling of the relative survival rates.
Results: Incidence rates were practically constant over the period 1953-1997 and ranged between 0.6-0.8 per 100.000 per year for both sexes. Age-specific incidence rates were 1 per 100.000 at age 45-49 and increased to 5 per 100.000 at age 80-84. The cumulative 5 year relative survival was 76% for men and 72% for women. After adjusting for age and length of follow-up, the relative survival rates have significantly improved over the calendar years. The relative excess risk of dying due to eye melanoma significantly decreased by 47% between 1955-64 to 1985-94. Sex was not an independent predictor for the relative survival.
Discussion: The practically unchanged incidence rate for eye melanoma over a calender period of 45 years until the mid 1990ies and a sex ratio of about 1:1 gives some evidence that constitutional or genetic factors might be important in the etiology of eye melanoma. The relative survival has considerably improved from 1953 to 1994.
Institute for Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, Hufelandstr. 55, 45122 Essen, Germany
Finnish Cancer Registry, Liisankatu 21 B, 00170 Helsinki, Finland