Clinical analysis of patients with skeletal metastasis of lung cancer

Abstract

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.

Keywords: Bone neoplasms; Lung neoplasms; Multivariate analysis.

Fig. 1

A 66-year-old man who visited our hospital for hemoptysis. a Chest X-ray showed right costo-phrenic angle blurring. b Chest CT scan showed a 4 cm-sized mass. Squamous cell carcinoma was diagnosed by bronchoscopic biopsy. c At the time of diagnosis, the stage was T3N2M0. d At follow-up, WBBS was performed at 20 months of diagnosis, and hot-uptake was observed at the 2nd Lumbar body, left distal femur diaphysis and right distal tibia diaphysis. e The osteolytic lesions are observed in the lateral cortex of the left femur diaphysis and lateral cortex of right tibia diaphysis, suggesting skeletal metastases. f In chest X-ray, the haziness was increased at the right mid and lower lung field. g Curettage, flexible intramedullary nailing, plate fixation and bone cementing were performed on the right distal tibia diaphysis metastasis. Interlocking intramedullary nailing was performed on the left femur distal diaphysis metastasis. Additional postoperative radiation therapy was performed, and chemotherapy was continued. h Ten months after surgery, there was a slight increase in the size of the osteolytic lesions around the surgical sites, but full weight bearing without pain was possible. i The patient expired from pneumonia associated with lung cancer

Fig. 2

Kaplan-Meier plots of lung cancer survival according to a) age at diagnosis of lung cancer, b) pathologic type of lung cancer, c) whether chemotherapy was performed for skeletal metastasis, and d) whether radiation therapy was performed for skeletal metastasis. Median survivals are expressed in months. Statistical significance was assessed by the log-rank test

Fig. 3

Kaplan-Meier plots of skeletal metastasis survival in a) age at diagnosis of lung cancer, b) pathologic type of lung cancer, c) whether chemotherapy was performed for skeletal metastasis, and d) whether orthopedic surgery was performed for skeletal metastasis. Median survivals are expressed in months. Statistical significance was assessed by the log-rank test

Fig. 4

Decision-making diagram for skeletal metastasis in patients with lung cancer