Distinct metastatic spread and progression patterns in patients treated with crizotinib for ROS1- and ALK-rearranged non-small cell lung cancer: a single-center retrospective study

BACKGROUND: Crizotinib has been approved for C-ros oncogene 1 (ROS1)- and anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) patients. Few studies have examined the differences in crizotinib treatment outcomes between these patients and the progression sites during treatment. We investigated the metastatic spread, crizotinib efficacy, and progression patterns during crizotinib treatment in ROS1- and ALK-rearranged NSCLC patients. METHODS: We retrospectively reviewed crizotinib-treated ROS1- and ALK-rearranged NSCLC patients between January 2011 and March 2021. Patient characteristics, clinical outcomes, and progression patterns during treatment were collected from medical records. The metastasis extent, crizotinib response, and progression patterns between the groups were compared. RESULTS: We identified 26 patients with ROS1- and 42 with ALK-positive NSCLC. The baseline proportion of central nervous system (CNS) metastases did not differ between the groups (12% vs. 29%, P=0.10), but the proportion of extrathoracic metastases, including CNS metastases, was significantly higher in ALK-positive than in ROS1-positive NSCLC patients (35% vs. 71%, P=0.003). Regarding the response to crizotinib, the objective response rate (ORR), progression-free survival (PFS), or overall survival (OS) did not significantly differ between the groups (ROS1 vs. ALK, ORR: 69% vs. 69%, P=0.987; PFS: median 10.9 vs. 10.7 months, P=0.232; median OS: not reached vs. 67.7 months, P=0.495). The CNS was the most common metastasis site in both groups [ROS1 vs. ALK, 69% (11/16) vs. 46% (17/37), P=0.127], and the cumulative incidence of CNS metastasis did not differ between the groups (P=0.914). CONCLUSIONS: Crizotinib treatment outcomes, including progression patterns, were similar between ROS1- and ALK-positive NSCLC patients.