Genetic instability in cancer: theory and experiment.

Epidemiologic data and molecular biology have combined to demonstrate that multiple genetic changes may be required in carcinogenesis. Mutator mutations, defined as genetic changes which increase the rate of genetic change, including both single base changes and chromosomal instability, may accelerate this process. Key questions remain in defining the role of mutator mutations in carcinogenesis as well as in cancer therapy. Theoretical approaches, including deterministic and stochastic models, have played a significant role in hypothesis generation, experimental design, and refinement of conclusions in this field, and are expected to continue to do so in the future.