Applicability of Mathematical Model for Evaluating Cancer Mortality Risk

The mathematical cancer evaluation model, the Generalized Moolgavkar-Venson-Knudson (G-MVK) model and the two-stage MVK model, were applied to Japanese cancer mortality statistics to examine the applicability of the models for estimating the mortality risk with its year and age dependent variation. First the G-MVK model was simplified with the constant mutation parameters, and was applied to determine the number of stages required for cancer induction for sixteen kinds of cancers and total solid cancer. Then the G-MVK model and the two-stage MVK model were compared in their estimation accuracy, and the latter model was calibrated with the Japanese lung cancer and leukemia statistics. The main results obtained under the limits considered in this study are as follows: (1) the number of stages required for cancer induction was determined by numerical fitting with the cancer statistics. The estimated stage number depended on the kind of cancer, and the mortality depended on age and year, (2) the two-stage MVK model was well calibrated with the statistics and was promising for depicting cancer mortality risk, and (3) the combined (one-stage and two-stage) MVK model was applied to leukemia to show that the hereditary chances of leukemia mortality can be depicted under the assumption that some people were born with an intermediate stem cell.