Impact of denosumab use on the survival of untreated non-squamous non-small cell lung cancer patients with bone metastases

Denosumab reduces the incidence of skeletal-related events (SREs) in solid tumor patients with bone metastases (BM). However, there have been no detailed reports of the efficacy of denosumab in untreated non-squamous non-small cell lung cancer (NSCLC) patients with BM. The medical records of patients with untreated non-squamous NSCLC and BM at diagnosis at our institution were reviewed retrospectively. The overall survival (OS) and the time to SREs were analyzed according to the treatment for the BM. Of the total of 149 patients who were eligible, 52 had received denosumab (Dmab group), 51 had received zoledronic acid (ZA group), and 46 had received no treatment (No-Tx group) for the BM. The frequencies of prior SREs were higher in the Dmab group and ZA group than in the No-Tx group (44, 41 and 22%, respectively); however, there were no significant differences in any of the other clinicopathological characteristics examined among the three groups. The median OS in the Dmab group, ZA group and No-Tx group were 21.4 months, 12.7 months and 10.5 months, respectively; the OS was significantly longer in the Dmab group than in the ZA group (P < 0.01). Results of multivariate analysis revealed that denosumab treatment was significantly associated with a more favorable survival [hazard ratio, 0.500; 95% CI 0.332-0.741; P < 0.01]. No significant difference in the time to SREs was observed among the three groups. Our results suggest that treatment with denosumab may improve the overall survival of non-squamous NSCLC patients with BM.