BackgroundIn addition to improving survival outcomes, new oncology treatments should lead to amelioration of patients’ quality of life (QoL). Herein, we examined whether QoL results correlated with PFS and OS outcomes in phase III randomized controlled trials (RCTs) investigating new systemic treatments in metastatic non-small cell lung cancer (NSCLC).MethodsThe systematic search of PubMed was conducted in October 2022. We identified 81 RCTs testing novel drugs in metastatic NSCLC and published in the English language in a PubMed-indexed journal between 2012 and 2021. Only trials reporting QoL results and at least one survival outcome between OS and PFS were selected. For each RCT, we assessed whether global QoL was “superior,” “inferior,” or with “non-statistically significant difference” in the experimental arm compared to the control arm.ResultsExperimental treatments led to superior QoL in 30 (37.0%) RCTs and inferior QoL in 3 (3.7%) RCTs. In the remaining 48 (59.3%) RCTs, a statistically significant difference between the experimental and control arms was not found. Of note, we found a statistically significant association between QoL and PFS improvements (X2= 3.93,p= 0.0473). In more detail, this association was not significant in trials testing immunotherapy or chemotherapy. On the contrary, in RCTs testing target therapies, QoL results positively correlated with PFS outcomes (p= 0.0196). This association was even stronger in the 32 trials testing EGFR or ALK inhibitors (p= 0.0077). On the other hand, QoL results did not positively correlate with OS outcomes (X2= 0.81,p= 0.368). Furthermore, we found that experimental treatments led to superior QoL in 27/57 (47.4%) trials with positive results and in 3/24 (12.5%) RCTs with negative results (p= 0.0028). Finally, we analyzed how QoL data were described in publications of RCTs in which QoL outcomes were not improved (n= 51). We found that a favorable description of QoL results was associated with sponsorship by industries (p= 0.0232).ConclusionsOur study reveals a positive association of QoL results with PFS outcomes in RCTs testing novel treatments in metastatic NSCLC. This association is particularly evident for target therapies. These findings further emphasize the relevance of an accurate assessment of QoL in RCTs in NSCLC.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12916-023-02953-0.