Fig. 2.

Identification of predictors using the Lasso Cox regression. a Selection of tuning parameter (λ) in the LASSO regression using 10-fold cross-validation. The vertical line was plotted using the minimum criteria and the one standard error of the minimum criteria. b LASSO coefficient profiles of variables. Each colored line represents a variable in the model. With increases in λ, the coefficient of each variable decreased. At the optimal values log (λ) = − 2.375, five variables (KPS, abdominal distention, edema, QOL, and duration of pain) with a nonzero coefficient were selected