Heredity, age and cancer

A factor analysis of mortality from gastric cancer in the populations of 41 countries has been made. It is concluded that the interrelation between age and cancer has both a biological and a chronological component. On the one hand, tumour development is linked to the molecular-genetic and systemic-physiological mechanisms of ageing. On the other, increasing mortality from cancer with age reflects the number of years for which the organism was exposed to the carcinogenic action. Each of these mechanisms is illustrated by the factor model of mortality from gastric cancer. Hereditary effects on both mechanisms that relate age and cancer are discussed.