Prognosis of different bone metastases patterns in EGFR-mutant advanced lung adenocarcinoma patients

Abstract

Abstract Introduction Bone metastases at initial diagnosis of lung cancer was associated with worse prognosis, compared with non-bone metastases. However, whether there was survival difference in different bone metastases patterns between bone metastases without extrathoracic metastases (BM), simultaneous bone metastases and other extrathoracic metastases (BMM) in real-world setting was unclear. Methods Advanced lung adenocarcinoma patients with initial bone metastases who receiving first-line first-generation Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and EGFR T790M guided Osimertinib as second-line therapy were retrospectively screened. The first-line real-world progression-free survival (1LrwPFS), second-line real-world progression-free survival (2LrwPFS), post-progression survival (PPS) and real-world overall survival (rwOS) were evaluated. Results A total of 126 patients were enrolled. Patients with BMM had worse rwOS (35.2 months vs. 42.9 months, HR = 0.512, P = 0.005) and shorter 2LrwPFS (12.8months vs. 17.0 months, HR = 0.575, P = 0.011), compared with BM group. There was no statistically significant difference in 1LrwPFS (12.7months vs. 14.0months, HR = 0.838, P = 0.333) and PPS (10.6 months vs. 6.2months, HR = 0.731, P = 0.152) between BM and BMM group. Linear regression and Spearman rank correlation analysis demonstrated 2LrwPFS was strongly correlated with rwOS (r = 0.621, P = 0.000, R2 = 0.568). In multivariate analysis, patients with BMM (P = 0.002), performance status(PS) score ≥ 2 (P ＜0.001) and TP53 alteration positive (P = 0.003) were independent prognostic factors of worse rwOS. Conclusion Different bone metastases patterns had different survival outcome. In addition, 2LrwPFS had a high impact on rwOS for EGFR-mutant advanced lung adenocarcinoma patients receiving first-line first-generation EGFR-TKI and Osimertinib as second-line therapy.