OPTIMIZATION OF MOLECULAR GENETIC DIAGNOSTICS OF PATIENTS WITH ADVANCED NON-SMALL CELL LUNG CANCER BY INTRODUCING ROS1 TESTING IN THE REPUBLIC OF KAZAKHSTAN

Relevance: Currently, molecular diagnosis in NSCLC Kazakhstan includes detection of EGFR, ALK driver mutations status, and PD-L1-status, but not ROS1, what limits the access patients with this mutation to vital therapy.
 The study aimed optimize methods genetic by introducing ROS1 testing Republic Kazakhstan.
 Methods: biopsy surgical material non-small cell lung cancer (NSCLC) fixed 10% buffered formalin was studied. After initial morphological adenocarcinoma, status determination, ALK-negative tumor assays were sent for further determination status. First, we performed immunohistochemistry (IHC) using Ventana BenchMark Ultra platform antibody (SP283) OptiView DAB Detection Kit imaging system. that, samples positive doubtful IHC results RT-PCR (reverse transcriptase polymerase chain reaction) confirm status.
 Results: A total 99 from EGFR-negative adenocarcinoma studied January 01 till September 30, 2022. staining assessed as: 0 (negative) – 59 samples, 1+ 25 2+ (doubtful) 12 3+ (positive) 3 samples. Cases ≥70% immunostaining considered positive. Samples an stain score (doubtful), (positive), a few confirmation PCR.
 Overall, 22 tested RT-PCR, as follows:1 (4%) positive, 13 (59%) negative, 8 (37%) -– invalid.
 Conclusion: large proportion questionable obtained when determining IHC, invalid during subsequent testing. Choosing nationwide implementation, one should evaluate economics be implemented compare them standard validated FISH method.