Multicenter study of zoledronic acid administration in non-small-cell lung cancer patients with bone metastasis: Thoracic Oncology Research Group (TORG) 1017.

Skeletal-related events (SREs) may occur at the time of first diagnosis in 20-30% of lung cancer patients with bone metastases. Several clinical trials have shown that zoledronic acid (ZA) is effective for decreasing SREs. The main objective of the present study was to discuss clinical data of ZA and compare the frequency of SREs with previous reports. All patients with non-small-cell lung cancer (NSCLC) with metastatic bone disease who were administered ZA at least twice between January 2008 and December 2009 were eligible for inclusion in the study. In total, 198 consecutive patients were identified. The median duration of ZA administration was 106 days [95% confidence interval (CI), 92-133 days], and the median number of ZA administrations was 4 (range, 2-41). The median time to first SRE in patients who experienced SRE following ZA treatment was 202 days (95% CI, 156-264 days). Among the 78 patients who had already experienced SRE prior to ZA treatment, 35 (45%) experienced SRE subsequently after starting ZA treatment. On the other hand, among the 120 patients without a history of SRE before starting ZA treatment, 42 (35%) experienced SRE after the start of ZA administration (P=0.16). No osteonecrosis of the jaw (ONJ) was reported in any of the patients. The present study revealed that ZA had a certain level of efficacy regardless of the presence or absence of prior SREs. However, the duration of ZA therapy was short in this study; further accumulation of data on the long-term prognosis and incidence rates of ONJ and other late complications of ZA therapy seems to be particularly important.