Prospective study on incidence of bone metastasis (BM) and skeletal-related events (SREs) in patients (pts) with stage IIIB and IV lung cancer (CSP-HOR13).

Abstract

7545 Background: Although the overall incidence of BM is not known, bone metastases are a frequent complication in pts with advanced lung cancer. Bone metastases can be associated with SREs, which include pathologic fracture, need for surgery or radiation to bone, spinal cord compression, and hypercalcemia of malignancy. The aim of our study is to investigate prospectively the incidence of BM, the incidence and types of SREs, time interval between BM and SREs, influence of SREs on QOL, and predictive factor of SREs. Methods: Eligibility criteria for enrolment were a newly diagnosed pt with stage IIIB or IV lung cancer, age over 20 years old, written informed consent. Staging of lung cancer required CT scan of the chest and upper abdomen, bone scan or PET scan, and CT or MRI scan of the brain. Pts were closely followed up every 4 weeks to see if they developed SREs. During the follow up period the pts underwent CT scan of the chest and upper abdomen every 4 weeks, CT or MRI scan of the brain and bone scan or PET scan every 6 months. A QOL questionnaire was carried out at enrollment, 3 months and 12 months. Treatment for lung cancer and use of zoledronate were at the discretion of the investigator. Results: Two hundred and seventy four pts were enrolled into the study between Apr. 2007 and Dec. 2009 from 12 institutions. Median age was 68 years, small cell/non-small cell=77/197, IIIB/IV=73/124, M/F=193/81, PS 0/1/2/3-4=76/171/23/4. Median follow up time was 10.3 months (0-27.2 months). Seventy eight of 124 pts with stage IV (62%) already had BM at the time of enrollment. Twenty four of 78 pts with known BM (31%) had some kind of SREs concomitantly. Additional 11 pts developed SREs during follow up time and the total incidence of SREs was 45%. Thirty one of 196 pts without initial BM (15%) developed bone metastases, and 14 of these 31 pts developed SREs during the follow up period. The type of SREs was pathologic fracture 4.7%, radiation to bone 15.3%, spinal cord compression 1.1% and hypercalcemia 2.2%. Conclusions: The incidence of BM at initial diagnosis was 62% and was higher than initially expected. Various SREs developed in 17 % of all the pts during the follow up period.