Susceptibility to cancer and spontaneous incidence.

Susceptibility to cancer implies being easily affected by carcinogen, as well as having an overt spontaneous incidence of cancer. The susceptibility of a population to the development of fatal cancer of a given organ can be represented by a frequency distribution. This distribution depends both upon the genetic susceptibility of the population and upon all environmental carcinogens that have impinged on that population. The method for construction of such a susceptibility distribution has been simplified and applied to experimental data on bone tumor induction with 90Sr in mice, and to bone tumor mortality and prostate cancer mortality in man. The relative susceptibilities of different human organs to the development of fatal tumors can be defined in terms of the spontaneous tumor mortalities.