“…Four studies [18,19,21,24] were specifically devoted to PS2 patients, while two trials [22,25] reported subgroup analysis for PS2 patients (18 and 20%, respectively) within larger randomized phase III trials. All trials compared a platinumbased doublet with single-agent chemotherapy; four of these [18,21,22,24] compared carboplatin-based doublet with single agent chemotherapy: carboplatin plus pemetrexed vs pemetrexed alone [18], carboplatin plus gemcitabine vs gemcitabine alone [21,24], carboplatin plus paclitaxel vs paclitaxel alone [22,25]; the other two trials compared cisplatin plus gemcitabine with gemcitabine alone [19] and cisplatin plus vinorelbine or vindesine with vinorelbine alone [23]. In nearly every trial characteristics were well balanced between two arms.…”