[Use of models in the study of survival in oncology]

Observation of numerous survical surves connecting the survival rates with time usually expressed in yearly intervals has permited the elaboration of patterns describing survival probability in terms of time. Gross survival patterns, from which the most utilized is the exponential pattern, must be distinguished from comparative surival patterns that debouch into the recovery probleme. Their interest is to caracterize survival for a group of patients with the assistance of a limited number of values (three at most). From that, follow their practical applications: comparison between several groups that may differ either from the characteristics of the discase or from the received treatments and from the vital future forecasting, either on one group's level, or for an individual.