Precancer of the prostate.

The evolution of the malignant phenotype requires a set of genetic and epigenetic changes in sets of genes responsible for regulation of normal growth and cell death, of "social behaviour" and differentiation. The sum of these changes, not only the sequence, determines the malignancy as well as its grade. The probability of invasiveness shows a remarkable relationship to morphological changes, which in turn prove to be accompanied by a multitude of discrete molecular perturbations. Some of these can be characterized as functional, others as inductive with respect to their participation in the process. Since only the functional changes regulate malignant behaviour per se, it is an important task for future research to assemble a set of such changes, find markers for them and combine morphological and molecular indicators to achieve prognostically optimal scores. It should be emphasized, though, that rational use of such scores using biopsy samples as a source of information cannot be defined until biopsy strategies have been standardized and optimized.