The probability of developing cancer within defined age-intervals or during life-time was assessed for the population of Saarland, Germany in 1970-1972 and 1980-1985 based on life-tables and age-specific cancer incidence rates. As a result of increasing life expectancy and, for some forms of cancer, increasing age-specific incidence rates, the probability at birth of eventually developing a malignant neoplasm (ICD-9 140-208) increased from 24.12% in 1970-1972 to 32.35% in 1980-1985 in men, and from 24.76 to 29.72%, respectively, in women. Comparable calculations are presented and discussed for all of the most common malignancies in women and men. The relation to common measures of descriptive epidemiology, mainly the cumulative rate and the cumulative risk, is numerically illustrated.