title: [The relation between pathologic factors of esophagus cancer and prognosis of its sufferers: application of Cox's model].
abstract: Yanting and Langzhong counties in Sichuan Province are among the areas with highest esophagus cancer mortality in China. We collected 218 patients who received only surgery from 1972-1981 in Yanting Cancer Research Institute and had followed up till 1986. The data includes the survival time, age, cancer size and some other pathological factors, 11 in total. By using the self-compiled software SURVIVAL, we found 5 factors affected the prognosis of esophagus cancer sufferers significantly, i.e. age, cancer size, invasion depth, pattern of growth and fibrous encapsulation. The model is lambda(t,X) = lambda 0(t) exp (.0264 x2 + .165 1x4 + .639 7x8 + .353 2x9 - .753 9x11). We can estimate lambda 0(t) either parametrically or nonparametrically. For example, using the Weibull full-parametric model, the estimation is: lambda 0(t) = .0008133 t0.2716 with the full--parametric model, the survival function for different Prognosis Index I(X) can be estimated conveniently. Here I(X) = .026 4x2 + .165 1x4 + .639 7x8 + .353 2x9 - .753.9x11. Because of the use of the compiled BASIC program with Chinese explanation, the SURVIVAL is convenient to use and the speed is 4-5 times greater than explained BASIC.
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
mesh_terms: D002681:China / Q000453:epidemiology; D004938:Esophageal Neoplasms / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D012984:Software; D016019:Survival Analysis