Skeletal related events in patients with bone metastasis arising from non-small cell lung cancer.

Purpose: The skeleton is one of the most common sites of metastasis in patients with non-small cell lung cancer (NSCLC). Metastasis increases the risk of skeletal-related events (SREs). The purpose of this study is to evaluate the incidence of SREs and the factors associated with the development of SREs in patients with bone metastases (BM) arising from NSCLC.

Methods: A cohort study was carried out involving 95 patients with BM associated with NSCLC who were enrolled between 2007 and 2011. Clinical and sociodemographic data were extracted from the physical and electronic records. The association between exposure variables and outcome (SREs) was assessed using crude odds ratio (OR). Survival analysis of patients with BM was conducted using the Kaplan-Meier method. A log-rank test was used to assess differences between the curves of those who did and did not experience SREs.

Results: Sixty-two out of 95 patients with BM (65.3 %) showed evidence of at least one SRE. Multiple analysis revealed that patients with a history of smoking (OR = 6.76; 95% CI = 1.3-33.0; p < 0.01), performance status ≥2 (OR = 3.38; 95% CI = 1.2-9.3; p < 0.01), and multiple BM (OR = 3.31; 95% CI = 1.1-9.9; p < 0.03) were at greater risk of SREs. Median survival time was 4.6 months (95% CI = 2.9-6.2) in patients who experienced SREs and 6.8 months (95% CI = 2.2-11.4) in patients who did not, a statistically significant difference (p = 0.03).

Conclusion: Patients with NSCLC are more likely to experience SREs if they have poor performance status, a history of smoking or multiple BM. Global survival was shorter in patients who suffer SREs.