The interpretation of time trends and geographical differences of population-based survival rates is generally not easy, due to the difficulty in disentangling the effects of observational biases, diagnostic and therapeutic procedures and their interactions.
Whereas descriptive analysis of relative survival is generally based on survival levels estimated at fixed time since diagnosis, interpretation issues can take advantage from the analysis of the shape of the considered relative survival.
Parametric survival models allowing the estimation of the fraction of cured patients are applied here to analyze and discuss the differences in colon cancer relative survival between European countries, according to age and period of diagnosis.
The survival curves of colon cancer patients are described according to 2 parameters : the proportion of cured patients and the mean survival time of fatal cases.
These parameters are estimated by least square nonlinear regression of relative survival values derive from the EUROCARE Project publication.
Exponential and Weibull survival functions are used to model the relative survival curve for the fraction of fatal cases.
The Weibull model gives generally a better fit with respect to the exponential model, thus indicating that the mortality rate for fatal cases is decreasing with time since diagnosis.
For the youngest patients, however, the 2 survival functions give practically overlapping estimates. (...)
Mots-clés Pascal : Tumeur maligne, Côlon, Courbe survie, Survie, Guérison, Loi Weibull, Fonction exponentielle, Modèle statistique, Epidémiologie, Europe, Homme, Appareil digestif pathologie, Intestin pathologie, Côlon pathologie
Mots-clés Pascal anglais : Malignant tumor, Colon, Survival curve, Survival, Cure, Weibull distribution, Exponential function, Statistical model, Epidemiology, Europe, Human, Digestive diseases, Intestinal disease, Colonic disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0310274
Code Inist : 002B04B. Création : 27/11/1998.