Utility of Repeated NGS Testing in Myeloid Diagnostic Work Up. (9th November 2022) - Zhu, Y
Abstract: Introduction/Objective: NGS is an integral component of diagnostic work-up of myeloid neoplasms, commonly applied at initial diagnosis and for assessment of treatment response. It is less clear how NGS should be repeated at disease follow-up when initial result is negative. In order to assess the utility of repeated NGS testing, we retrospectively analyzed results in patients with multiple tests. Methods/Case Report: Myeloid NGS results were collected between 10/2017 and 4/2022 at University of Miami. The results were grouped by patients and arranged by collection date and finding of mutations. First, we identified patients with negative result or a single mutation of common CHIP gene TET2, DNMT3A, or ASXL1 (DAT) in the first available NGS test. Then we divided these patients into negative follow-up group, if all NGS results were the same as the initial test, and positive follow-up group, if any new mutations were detected. The NGS findings were correlated with clinical history and pathology diagnosis. Results (if a Case Study enter NA): Results from 876 patients were analyzed. A total of 362 patients underwent multiple NGS tests; among them, 84 were negative and 14 had a single DAT mutation in the first NGS test. Among the 98 patients, 21 (21.4%) were in the positive follow-up group, with median time-to-positive at 132 days; the other were in the negative follow-up group with median follow-up time at 258 days. Analysis of the patient history showed the positive follow-up group consists 16 patients who were in remission of high-grade myeloid neoplasm at the time of initial testing and relapsed at the time of detection of mutations, 4 patients who acquired alteration of uncertain significance after hematopoietic stem cell transplant, and 1 patient who acquired KRAS mutation corresponding to MDS developed 846 days after the initial testing. Conclusion: Positive conversion in repeated NGS testing are mostly associated with relapsed myeloid neoplasm after chemotherapy.