P378 Molecular diagnostic markers for childhood acute leukaemia – a single centre experience

Background Acute lymphoblastic leukaemia (ALL) is the most common malignancy during childhood and has a high cure rate. On the other hand, the prognosis of acute myeloid leukaemia (AML) remains poor despite progress achieved over the past decade. Aim Correlation between molecular genetics and treatment response of paediatric leukaemia patients Methods 49 patients diagnosed with acute leukaemia in the OncoHematology Paediatric Unit between January 2015 and December 2016 were analysed for bone marrow gene alterations. For ALL patients the mutational status of the ABL-BCR, MLL-AF4, TEL-AML1, E2A-PBX genes was assessed and for AML patients, the mutational status of AML-ETO, PML-RARa, FLT3, NPM1 fusion genes. Results 7 of 31 ALL patients had TEL-AML fusion present and one of them showed E2A-PBX fusion present. The other genes tested came out absent. All patients were submitted to protocol ALL-IC BFM 2002 treatment. On day 33 of treatment complete remission was confirmed for all of them. One patient had an early relapse but with no modification in gene rearrangement. Out of 18 AML patients, 2 had present PML-RARa mutation, while another 2 had present FLT3; in addition, one of them also tested positive for NPM1 mutation. All patients received treatment according to AIEOP AML protocol. We lost two patients in the early stage of the treatment, one of them with both FTL3 and NPM1 mutations present. Conclusions This study is a step towards the complete and modern diagnosis of children with acute leukaemia, in our centre. Different oncogenic profiles can be related to different therapeutic responses, which means that targeted therapeutic approaches are necessary.