Assessing the Prognostic Significance of Baseline Liver Metastasis in ALK Fusion-Positive Metastatic Lung Cancer: A retrospective study

<bold>Background:</bold> The presence of targeted therapy has improved the prognosis of ALK Fusion-Positive metastatic lung cancer, however, the prognostic significance of baseline liver metastases in ALK Fusion-Positive metastatic lung cancer has not been well studied. <bold>Material and Methods:</bold> Patients who were originally diagnosed with stage IIIB and stage IV ALK Fusion-positive metastatic lung cancer from January 2014 through December 2022 were analyzed in this retrospective study. The patients are divided into two groups based on the presence or absence of liver metastasis. <bold>Results:</bold> A total of 55 patients were enrolled for final analysis. There were 14 (25.5%) patients aged over 65, and 25 (45.5%) patients were male. A total of 9 (16.4%) patients had liver metastasis. Median progression-free survival (mPFS) was poorer in patients with liver metastases (5.6 months (95% confidence interval [CI] 2.5-15.4) versus 19.6 months (95% CI 10.7-33.5), P=0.014). Median overall survival (mOS) was poorer in patients with liver metastases as well (14.6 months (95% CI 4.03-43.0) versus 79.2 months (95% CI 45.2-79.2), P=0.003). We performed both univariate and multivariate analyses for PFS and OS, revealing that liver metastasis independently predicted negative outcomes for both PFS (HR: 4.98, 95% CI 1.12-5.63, P=0.025) and OS (HR: 5.93, 95% CI 1.78-16.3, P=0.002). <bold>Conclusion:</bold> In patients with ALK Fusion-Positive metastatic lung cancer, baseline liver metastases were found to be an independent poor prognostic factor for PFS and OS.