Incidence and Risk Factors for Bone Metastasis in Non-Small Cell Lung Cancer

BACKGROUND: Bone is a frequent site of metastasis from various primary cancers including with Non-Small Cell Lung Cancer. The aim of this study was to investigate the incidence and risk factors for Bone Metastasis in patients with Non-Small Cell Lung Cancer. METHODOLOGY: A cohort study was carried out in patients diagnosed with Non-Small Cell Lung Cancer between 2006 and 2014 in a single cancer centre. A descriptive analysis of the population was compiled based on mean ± standard deviation (SD) for continuous variables and percentage (%) for categorical variables. Univariate and multivariate Cox proportional hazards regression analyses were carried out to quantify the relationship between independent variables and the outcome variable (Bone Metastasis). RESULTS: During the study period 1025 patients were diagnosed with Non-Small Cell Lung Cancer. Bone Metastasis was detected in 136 patients (13.2%) with a mean interval between Non-Small Cell Lung Cancer diagnosis and Bone Metastasis of 8.07 months (95% CI: 7.68 8.45). Multivariate analysis revealed that younger age (HR 0.97; 95%CI, 0.95–0.99; p=0.002), adenocarcinoma (HR 1.51; 95%CI, 1.06–2.15; p=0.021) and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy (HR 3.73; 95%CI, 2.30–6.05; p<0.001) were associated with the occurrence of Bone Metastasis. CONCLUSION: The incidence of Bone Metastasis was 13.2%. Younger age, histological subtype adenocarcinoma and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy are independent risk factors for Bone Metastasis.