Prognostic Factors in Lung Adenocarcinoma with Bone Metastasis Treated with EGFR-TKIs

Background and Objectives: Patients who have advanced lung cancer and bone metastasis (BM) often suffer from skeletal-related events (SREs) that lead to poor quality of life and poor prognosis. Our study aimed to investigate the prognostic factors in patients with BM from epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma. Materials and Methods: This retrospective study included 77 lung adenocarcinoma patients with synchronous BM. These patients had first-line EGFR tyrosine kinase inhibitors (EGFR-TKIs) between January 2017 and December 2019. Among them, 42 patients were treated with 120 mg of subcutaneous denosumab monthly. We investigated their baseline characteristics, cancer management, SREs, progression-free survival (PFS), and overall survival (OS). Results: The PFS in the patients treated with or without denosumab were 10.1 vs. 12.5 months (p = 0.971). The median OS was 26.9 vs. 29.5 months (p = 0.967) in no denosumab and denosumab groups, respectively. Univariate analyses showed benefit of afatinib in PFS and good performance status in OS. Conclusion: Those patients that took afatinib as first-line EGFR-TKIs had significantly longer PFS than those treated with other TKIs. Denosumab had no prognostic effect on PFS or OS.