2.2. Data collection and endpoint definition
tumor
BRAIN METASTASIS, TUMOR, LUNG METASTASIS, BONE METASTASIS, PRIMARY TUMOR, LIVER METASTASIS
The following data were collected for all eligible patients, age, sex, marital status, primary tumor site, histological type, differentiation, TNM stage, clinical stage, tumor size, bone metastasis, brain metastasis, liver metastasis, lung metastasis, and treatment information and survival outcome. In this study, 2 variables, age and tumor size, were grouped and visualized using the X-tile software to determine the optimal cutoff value (Fig. The X-tile analysis of best-cutoff points of age and tumor size variables. (A) X-tile plot of training sets in age; (B) the cutoff point was highlighted using a histogram of the entire cohort; (C) the distinct prognosis determined by the cutoff point was shown using a Kaplan–Meier plot (low subset = blue, middle subset = gray, high subset = magenta); (D) X-tile plot of training sets in tumor size; (E) the cutoff point was highlighted using a histogram; (F) Kaplan–Meier plot of prognosis determined by the cutoff point (low subset = blue, middle subset = gray, high subset = magenta).