Telomere loss limits the rate of human epithelial tumor formation
  Most human carcinomas exhibit telomere abnormalities early in the carcinogenesis process suggesting that crisis caused by telomere shortening may be a necessary event leading to human carcinomas. Epidemiological records of the age at which each patient in a population develops carcinoma are known as age-incidence data; these provide a quantitative measure of human tumor initiation and dynamics. If crisis brought on by telomere shortening is necessary for most human carcinomas, it may also be the rate limiting step. To test this, we compared a mathematical model in which telomere loss is the rate limiting step during carcinogenesis with age-incidence data compiled by the Surveillance, Epidemiology and End Results (SEER) program. We found that this model adequately explains the age-incidence data. The model also implies that two distinct paths exist for carcinoma to develop in prostate, breast, and ovary tissues. We conclude that a single step, crisis brought on by telomere shortening, limits the rate of formation of human carcinomas. 
Hermann B. Frieboes and James P. Brody