Forest plot of OS by subgroup (ITT population). Note: The HR was not calculated for subgroups where the number of patients in either the nivolumab group or the GEM or PLD group was < 10 patients. HRs (95% CI) were estimated using the Cox proportional hazards model. The UICC TNM Classification version 7 was used. BRCA1, breast cancer susceptibility gene 1; BRCA2, breast cancer susceptibility gene 2; ECOG, Eastern Cooperative Oncology Group; FIGO, International Federation of Obstetrics and Gynecology; GEM, gemcitabine; HR, hazard ratio; ITT, intention-to-treat; NA, not applicable; NLR, neutrophil to lymphocyte ratio; OS, overall survival; PD-L1, programmed cell death ligand-1; PLD, pegylated liposomal doxorubicin; TNM, TNM Classification of Malignant Tumors; UICC, Union for International Cancer Control.