Abstract:

BACKGROUND:Cytology specimens are the main samples used for the diagnosis of advanced lung cancer. The objective of our study was to assess anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 receptor tyrosine kinase (ROS1) genes by an amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR) using cytology specimens and to then evaluate the mutation frequency of ALK and ROS1 in non-small-cell lung cancer (NSCLC) patients. METHODS:A large cohort that consisted of 8180 NSCLC patients who were genetically tested using cytology samples or formalin-fixed and paraffin-embedded (FFPE) samples (tumor tissue or biopsy) from January 2015 to December 2018 were screened. The gene rearrangement ratio and clinical characteristics of the two sample groups were analyzed by SPSS software. RESULTS:In our hospital, cytology specimens are the main resource used for gene testing in NSCLC. In most cases, an abundant quantity of nucleic acid was extracted from the residual liquid-based cell pellet for testing the ALK and ROS1 genes. In certain cases, when the residual cell pellet was insufficient for the gene testing, the cell block and liquid-based cell smear served as alternative options. In addition, we retrospectively analyzed our previous data, and the mutation ratio of the ALK/ROS1 rearrangements obtained by using the cytology samples (4.98%/1.80%) and the FFPE samples (6.06%/1.62%) was almost the same (P-value = .09/.634). CONCLUSIONS:This study demonstrated that AMRS-PCR method can effectively identify ALK and ROS1 gene rearrangements and cytology specimens might be an excellent source for routine molecular testing in patients with advanced NSCLC.