Pattern of bone metastasis in patients with nonsmall cell lung cancer

Sir, With great interest, we read the article by Jazieh et al. on the pattern of bone involvement, management, and outcomes in patients with nonsmall cell lung cancer (August issue 2018, Ann Thorac Med).[1] The results of this article were interesting and agreeable contents. We have also been interested in bone metastasis and reported some articles.[2,3] We would like to ask the authors three questions. First, it is a question about the diagnosis of bone metastasis. The authors did not show the concrete number of patients how they diagnosed with bone scan, magnetic resonance, bone biopsy, or them. We do agree with the difficulty in recommending bone biopsy for unresectable lung cancer patients. Therefore, we agree with the diagnosis with images is realistic. If so, what is the optimal diagnostic method? In addition, please let us know how the authors differentiated diseases other than bone metastasis. Second, it is a question about the patients included in this study. The authors included 48 (18.5%) patients with stage I–III and 13 (5.1%) patients with unknown stage. Therefore, they included not a few patients without metastasis. We do wonder whether inclusion of these patients might be correct or not methodologically. Please explain the correctness of this inclusion. Third, it is a question about patients with liver and bone metastases at the same time. We would like to know whether metastasis in each organ was solitary or multiple one. Were there any other metastases organs in these patients? We do appreciate hearing from the authors whether the metastasis was dissemination to multiple organs or did the metastasis be limited to these two organs.