The diagnostic and prognostic values of BCR–ABL in haematological malignancies

Abstract

Background Haematologic malignancies (HM) are considered to be one of the top 10 malignant disorders with respect to the incidence as well as the cause of death in patients suffering from cancers. Collectively, they constitute approximately 9% of all cancer cases diagnosed in a year. Annual incidence rates of some of these cancers are consistently increasing. Fluorescent in-situ hybridization (FISH) is a frequently used genetic technique in haemato-oncology. FISH is a molecular cytogenetic technique that uses fluorescent probes that bind to only those parts of the chromosome with a high degree of sequence complementarity to detect small deletions and duplications that are not visible using microscope analysis. A new generation of BCR/ABL single fusion FISH probes has been developed with high specificity. The aim of this work is to assess the diagnostic and prognostic values of BCR–ABL in cases with ALL and CML supplied to the cytogenetic laboratory in South Egypt Cancer Institute. Patients and methods The authors reviewed medical data of patients with ALL and CML who had done cytogenetic analysis in the cytogenetic lab (supplied from patient admission archives unit, private clinics, researches, and from Upper Egypt universities and cancer institutes) during the period from the 1st of January 2010 to the 31st of December 2017. It included 1223 patients; 686 (56.1%) were males and 537 (43.9%) were females. Their ages ranged from 2 months to 80 years old. Results In all, 56.1% of the studied patients were males and 43.9% were females. B-ALL was presented in 612 (50%) of patients. T-ALL was presented in 150 (12.3%) patients. CML presented in 461 (37.7%) of patients. In case of B-ALL, there were 193 patients who had positive BCR–ABL, 172 patients of them received TKI in their regimen, and 419 patients had negative BCR–ABL. In case of T-ALL, there were 13 patients who had positive BCR–ABL (all of them received TKI in their regimen) and 137 patients had negative BCR–ABL. In case of CML, there were 438 patients who had positive BCR–ABL (all of them received TKI in their regimen) and 23 patients had negative BCR–ABL. BCR–ABL gene affects the outcome and response to therapy in patients with acute lymphocytic leukaemia and chronic myeloid leukaemia. BCR–ABL is essential in the diagnosis of CML. The latest development in the follow-up of leukemias is use of minimal residual disease (MRD) after induction therapy for prognosis as well as treatment planning. Conclusion First, BCR–ABL had great diagnostic and prognostic values. It has a great role in the treatment plan, prediction of remission rate, MRD, relapse, and overall survival in ALL and CML. Second, with the use of TKI in patients with positive BCR–ABL, BCR–ABL gene had no adverse effects on response to therapy and survival of patients with ALL.