Experience of ROS1 CDx platforms in the central laboratory of South Korea

To detect ROS1 rearrangement in NSCLC, three different assays including fluorescent in stiu hybridization (FISH), Amoy Dx reverse transcription polymerase chain reaction (RT-PCR) and Oncomine Dx Target Test (ODXTT) were routinely performed as a nationwide screening In South Korea. ROS1 FISH or RT-PCR was consecutively and ODXTT was selectively performed in routine practice. The basic clinicopathologic and analytic characteristics were performed on whole cohort. 238 (1.8%) of 13,533 NSCLC confirmed positive for ROS1 rearrangement. Among above cohort, clinically selected 110 ROS1-negative cases confirmed by RT-PCR were re-evaluated by ODXTT and ODXTT found additional four ROS1-positive cases. one of two ROS1 positive cases by ODXTT confirmed responsive to crizotinib and the other showed no response to crizotinib. The average age of patients in the ROS1-positive group was 61 years old, Female patients (58.4%) with ROS1-positive occurred more than male patients (41.6%). Turnaround time for each method were 5.2 days by FISH, 4.8 days by RT-PCR, and three weeks by ODXTT, respectively.