title: Curve models for comparative phase III trials: heterogeneity of the population.
abstract: Equations were calculated to describe survival on disease-free survival (DFS) curves related to control or adjuvant-therapy-treated patients. They allowed us to differentiate three different segments or populations in the survival curve on a semi-log scale describing high-risk, intermediate-risk and low-risk groups. The percentage of patients and the annual mortality in each risk group could be calculated from the coefficients of the equation. As an example, the DFS curves of the premenopausal breast cancer patients of the Milan group were composed of three segments in the control group and of two segments in the CMF-treated group.
mesh_terms: D001943:Breast Neoplasms / Q000401:mortality*; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D008954:Models, Biological; D011336:Probability; D012306:Risk