PB1747 ASSESSMENT OF FLT3 MUTATION IN ACUTE MYELOID LEUKEMIA: RESULTS OF A SPANISH DELPHI PANEL SURVEY

Background: Despite the value of FLT3 as selective marker that drives therapy and current guidelines recommendations of FLT3 testing in all patients with AML, it is unclear whether these recommendations are met in the real‐world setting. Aims: To gather expert opinions on the use of FLT3 testing in AML and to develop recommendations applicable to daily clinical practice. Methods: This was a cross‐sectional,one‐round Delphi survey study carried out among members of different cooperative groups of the Spanish Societies of Hematology and Hemotherapy, and Molecular Biology. The final 108‐item questionnaire was developed by a scientific committee formed by 10 specialists in the clinical and molecular management of AML. Questions were grouped into three sections: current situation, recommendations on FLT3 testing, and results reporting. The first two sections included questions regarding the use of FLT3 analysis in clinical practice, testing methods, obtaining results, sensitivity of the techniques, and quality control. Each question was answered using a 4‐point Likert scale and the median value of the four possible responses was calculated. Consensus was established when the sum of the responses ‘frequently’/’recommendable’ and ‘always’/’indispensable’ (in favor of the recommendation) and‘sometimes’/’optional’ and ‘never’/’not necessary’ (against the recommendation) was ≥66.6% of the total responses. Only fully completed questionnaires were analyzed. Results: Of 66 specialists who participated in the study, 54 (81.8%) completed the questionnaire. It was noteworthy that 7.4% of participants ‘never’ or ‘sometimes’ performed FLT3 ‐ITD testing, a percentage that increased to 11.1% for FLT3 ‐TKD testing. However, there was a consensus regarding the need to determine FLT3 mutation as well as FLT3 ‐ITD and FLT3 ‐TKD systematically, with 94.2%, 99.9%, and 100% of agreement, respectively. Moreover, although 7.4% of specialists did not perform or rarely perform FLT3 testing in parallel with cytogenetic testing, 94.2% agreed on the need for simultaneous FLT3 and cytogenetic analyses. Regarding FLT3 ‐ITD testing, quantitative fragment analysis was the technique used by 93.7% of specialists, and 56.2% agreed not to use next‐generation sequencing as the first diagnostic method. No trend was observed on the preference to use a particular technique for FLT3 ‐TKD. More than half of specialists reported that results of FLT3 ‐ITD and FLT3 ‐TKD testing were available in less than 7 natural days, although more than one third (33.3% for FLT3‐ ITD, 38.9% for FLT3 ‐TKD) recognized that the time interval was longer than 7 days. However, consensus was reached regarding the need to have FLT3 testing (ITD and TKD) results available within 3‐4 days, being mandatory in less than 7 days. Also, whereas 54.8% of specialists stated that quality control of FLT3 assays was ‘sometimes’ or ‘never’ performed in their centers, there was consensus (94.2%) considering that quality control was ‘indispensable’ or ‘recommendable’ using an external quality assessment (80.7%) or inter‐laboratory cross‐validation (65.4%). Description of the technique used for FLT3 analysis, sensitivity cutoff values, qualitative (positive/negative) and quantitative result of the type of mutation, and type of sample were ‘indispensable’ variables in the molecular biology report. Summary/Conclusion: This expert consensus shows that daily practice does not fully correspond to what experts recommend, highlighting the need for additional support and resources for optimizing FLT3 testing in AML at a national level.