[A computer simulation of outcome in early screening studies of cancers of the mouth cavity].

The purpose of the simulation was to design a specific cancer screening programme for squamous cell carcinomas of the head and neck to make detailed estimates of the outcomes of different screening programme options. Therefore, a mathematical model of screening (Eddy) was transformed and simulated with a computer programme. The model is designed as a Markov chain with 7 states and filled with clinical and epidemiological data. The results of the simulation are interpreted as representative for cancer of the oral cavity. Basing on the different system model outputs, mortality with and without screening, effect on life expectancy of the individual and the entire screened population, are discussed. For a screening interval of 6 months the increase in life expectancy for a person with cancer of the oral cavity is 5.3 years, for the entire population (men older than 40 years), however, life expectancy increases only by 9.8 days. The proportion of patients saved from tumour-associated death rose to 65%. The simulation showed a rapidly decreasing effect of the screening programme with longer screening intervals. Therefore, a public cancer screening programme is only useful with a screening interval of 6 months, and the effect on life expectancy is limited. For oropharynx and hypopharynx the possibilities of early stage detection of carcinomas are limited and nearly 60% of the cases with carcinoma of the larynx are already being treated at an early stage. The importance of public health education is emphasised.