Cancer screening Is a matter of open debate within the scientific community: on the one hand, its supporters maintain, that in the absence of reliable measures of primary prevention, the best approach to neoplastic diseases consists of screening and early diagnosis, when feasible.

On the other hand, there are those who oppose this position on the basis of the lack of "statistically significant" proofs, and maintain that the costs of screening are too high in relation to the benefits that can be derived from these measures of secondary prevention.

The opposing positions are particularly strong with regard to screening for colorectal cancer, which involves in fact high costs and is based on not so easily acceptable procedures for the subjects who undergo it. Yet the incidence of cancer of the colon-rectum is increasing worldwide, even though individual mortality is positively Influenced by early diagnosis. There have been numerous attempts to support the two positions scientifically: this book describes an approach to the problem, as yet unexplored, consisting of a mathematical model - obviously computerized - which simulates a screening campaign for colorectal tumors in a general population.

The model allows cost-benefit analysis in different epidemiological, clinical and economical scenarios and is therefore adaptable to every situation in which a decision process on a screening campaign is in progress.

The authors reached the conclusion that screening for colorectal cancer, carried out by means of the search for occult blood in the faeces, allows a high degree of detection of cancers in the initial stage, the possibility of removing a relevant number of adenomas (whose probability of developing into a neoplasia is about 10%), a marked reduction of destructive surgical interventions and, last but not least, a prolonged survival of affected patients. These results are also accompanied by foreseeable economic returns.