Prognostic effects of osteoclast inhibitors in extensive stage small cell lung cancer patients with bone metastases.

Bone metastases (BM) often induce skeletal-related events (SREs) and contribute to poor prognoses in patients with cancer. Osteoclast inhibitors (OIs), such as bisphosphonates (BPs) and denosumab, reportedly prevent SREs and improve quality of life in patients with non-small cell lung cancer and BM, but have not been tested in extensive stage small cell lung cancer (ES-SCLC) patients. From 238 SCLC patient records, the present study reviewed those of 58 BM patients, including 23 who were treated with OIs (OIs group) and 35 who were untreated (untreated group). Patient backgrounds were balanced between groups using propensity score matching, and survival curves were compared using the log-rank test. The median overall survival (OS) times were 8.41 and 12.52 months in untreated and OIs groups, respectively, but these did not differ significantly between groups (log-rank test, P=0.409). The 1-year OS rate was higher in the OIs group (56.1%) when compared with the control group (22.6%). The results indicated that OIs tend to prolong the short term survival of ES-SCLC patients with BM. To the best of our knowledge, this is the first study to examine the prognostic effects of OIs in SCLC patients. The results of the present study may highlight the possibility that OIs improve the prognosis of ES-SCLC patients with BM.