Table 2

Frequency of a selection of variables (p<0.05) that remained in 1000 bootstrap samples following stepwise Cox procedure

CovariateBootstrap inclusion frequency
With PD-L1Without PD-L1
ECOG PS100100
Liver metastases99.5100
Alkaline phosphatase99.599.8
Time from last chemotherapy91.191.2
PD-L1 expression80.4
Bone metastases48.478.3
TNM at diagnosis4944.8
Perioperative chemotherapy24.628.8
Number of previous lines for advanced disease25.120.9
Pelvic irradiation14.820.3
Number of disease sites21.716
Previous chemotherapy8.110.3
Non-visceral metastases5.86.4
  • ECOG PS, Eastern Cooperative Oncology Group performance status; NLR, neutrophil-to-lymphocyte ratio; TNM, tumor–node–metastases.