Clinical analysis of patients with skeletal metastasis of lung cancer.

Background: Many factors influence bone metastases of lung cancer, and several studies report about survival of skeletal metastasis. However, few studies have focused on identifying the prognostic factors for skeletal metastasis of lung cancer, especially following orthopedic surgery. We conducted a retrospective analysis of the clinical characteristics of skeletal metastasis from lung cancer and discuss the prognostic factors.

Methods: We performed a medical record review of 202 patients who were diagnosed with skeletal metastasis from lung cancer. Adenocarcinoma was found in 116 patients (57.4%), squamous cell carcinoma in 29 (14.4%), small-cell lung cancer (SCLC) in 37 (18.7%), and large-cell carcinoma and other types of cancer in 20 patients (9.9%). Orthopedic surgery for skeletal metastasis was performed in 41 patients (20.3%).

Results: Lung cancer survival was 12.1 months. After diagnosis of lung cancer, skeletal metastasis was found at a mean of 2.5 months, and skeletal metastasis survival was 9.8 months. Lung cancer survival in patients younger than 60 years was 13.8 months, and lung cancer survival in patients 60 years or older was 10.8 months (p = 0.009). Skeletal metastasis survival in patients younger than 60 years was 11.0 months, and skeletal metastasis survival in patients 60 years or older was 8.8 months (p = 0.002). Mean skeletal metastasis survival with surgery was 12.6 months and without surgery was 9.1 months (p < 0.000). In the multivariate analysis of lung cancer survival, age under 60 years [HR (95% CI) 1.549 (1.122-2.139), p = 0.008], non-small cell lung cancer pathology type [HR (95% CI) 1.711 (1.157-2.532), p = 0.008], chemotherapy for skeletal metastasis [HR (95% CI) 8.064 (3.981-16.332), p < 0.000], and radiation therapy for skeletal metastasis [HR (95% CI) 1.791 (1.170-2.742), p = 0.007] were significant, independent, good prognostic factors. In the multivariate analysis of skeletal metastasis survival, age under 60 years [HR (95% CI) 1.549 (1.124-2.134), p = 0.007], non-small cell lung cancer pathology type [HR (95% CI) 2.045 (1.373-3.047), p < 0.000], chemotherapy for skeletal metastasis [HR (95% CI) 7.121 (3.542-14.317), p < 0.000], and orthopedic surgical treatment for skeletal metastasis [HR (95% CI) 1.710 (1.148-2.547), p = 0.008] were significant, independent, good prognostic factors.

Conclusions: Patients who survived longer were less than 60 years old, received chemotherapy as treatment for skeletal metastasis, had NSCLC rather than SCLC, and underwent orthopedic surgery for skeletal metastasis.