ABSTRACT Introduction: Treatment-free remission (TFR) is a new goal of chronic myeloid leukemia (CML) therapy. TFR is feasible when the patient has achieved a deep and stable molecular response and met the criteria required to ensure its success. Treatment discontinuation should not be proposed to the CML patient if minimum conditions are not met. In Brazil, for example, molecular tests (BCR::ABL1) are not broadly available, making it difficult to monitor the patients adequately. Objective: In this sense, providing TFR recommendations for Brazilian physicians are therefore necessary. These recommendations include the main criteria checklist to start the TKIs treatment discontinuing process in patients diagnosed with CML and the population-eligible characteristics for treatment discontinuation. Method: Age, risk score at diagnosis, TKI treatment duration, BCR::ABL1 transcripts type, depth of the molecular response for treatment discontinuation, treatment adherence, patient monitoring and withdrawal syndrome are essential factors to consider in TFR. After TKI discontinuation, BCR::ABL1 transcripts monitoring should be more frequent. When a major molecular response loss is observed during the monitoring of a patient in TFR, the TKI treatment should be resumed. Conclusion: These recommendations should serve as a basis for medical professionals interested in proposing TKI discontinuation for CML patients in clinical practice. It is important to highlight that, despite the benefits of TFR for the patients and the health system, it should only be feasible following the minimum standards proposed in this recommendation.

ABSTRACT Introduction: Chronic Myeloid Leukemia (CML) is a myeloproliferative disease that affects mainly adults between 50 and 55 years. In Brazil, information from the Sistema Único de Saúde (SUS) Outpatient Information System indicates that 12,531 patients had the Autorização de Procedimento Ambulatorial (APAC) approved for the CML treatment in 2017. Disease monitoring through molecular response evaluation is critical to the care of CML patients. The quantitative PCR test (real-time polymerase chain reaction) provides adequate evaluation parameters that allow the health professional to intervene at the right moments in order to reduce the chance of progression of the disease, providing the best outcome to the patient, including the possibility of treatment discontinuation for eligible patients. Although the test is included in the Clinical Protocol and Therapeutic Guidelines (PCDT) of CML, it is not possible to monitor the molecular response within SUS since there is no reimbursement for this test. Objective: Obtain expert recommendations on the importance, financing, and reimbursement of molecular monitoring in SUS. Methods: Six CML experts with different perspectives participated in the panel. The discussion was based in the main publications about the quantitative PCR test in CML monitoring. Results: Experts' recommendations: Molecular monitoring should be part of the integral treatment of patients with CML to reduce the chances of disease progression and costs to the health system; The government should put into practice what is provided in the PCDT of Chronic Myeloid Leukemia in Brazil: performing the monitoring of the molecular response via quantitative PCR; The government should create a code with adequate nomenclature and reimbursement value in SIGTAP, so that the test is carried out and covered by the public health network, as it is contained in the PCDT of the disease and the existing APAC does not cover the operational costs for its performance; Patients with chronic phase CML should perform a quantitative PCR every 3 months and, after reaching the MMR, should perform the examination every 6 months, as recommended by international guidelines; Patients should be monitored in reference laboratories that are standardized according to the international scale; The laboratories that are within the reference public centers could absorb all the test demand in Brazil, and other centers could be qualified through an ABHH accreditation; Adequate molecular monitoring may allow some patients to stop taking drugs and selffinancing the molecular test for all SUS patients Conclusion: A solution for the molecular test (BCR-ABL1) funding is urgent to ensure the monitoring of CML patients in SUS. The savings that might be generated with patients that stop taking the medication when adequately monitored may finance the test.

ABSTRACT Chronic lymphocytic leukemia is the most common hematologic malignancy among adults in Western countries. Several studies show that somatic mutations in the TP53 gene are present in up to 50% of patients with relapsed or refractory chronic lymphocytic leukemia. This study aims to review and compare the methods used to detect somatic TP53 mutations and/or 17p deletions and analyze their importance in the chronic lymphocytic leukemia diagnosis and follow-up. In chronic lymphocytic leukemia patients with refractory or recurrent disease, the probability of clonal expansion of cells with the TP53 mutation and/or 17p deletion is very high. The studies assessed showed several methodologies able to detect these changes. For the 17p deletion, the chromosome G-banding (karyotype) and interphase fluorescence in situ hybridization are the most sensitive. For somatic mutations involving the TP53 gene, moderate or high-coverage read next-generation sequencing and Sanger sequencing are the most recommended ones. The TP53 gene mutations represent a strong adverse prognostic factor for patient survival and treatment resistance in chronic lymphocytic leukemia. Patients carrying low-proportion TP53 mutation (less than 20-25% of all alleles) remain a challenge to these tests. Thus, for any of the methods employed, it is essential that the laboratory conduct its analytical validation, documenting its accuracy, precision and sensitivity/limit of detection.

OBJECTIVES: The outcomes of refractory and relapsed acute myeloid leukemia (AML) patients in developing countries are underreported, even though the similar classic regimens are widely used. METHODS: We conducted a retrospective comparison of “MEC” (mitoxantrone, etoposide, and cytarabine) and “FLAG-IDA” (fludarabine, cytarabine, idarubicin, and filgrastim) in adults with first relapse or refractory AML. RESULTS: In total, 60 patients were included, of which 28 patients received MEC and 32 received FLAG-IDA. A complete response (CR) rate of 48.3% was observed. Of the included patients, 16 (27%) died before undergoing bone marrow assessment. No statiscally significant difference in CR rate was found between the two protocols (p=0.447). The median survival in the total cohort was 4 months, with a 3-year overall survival (OS) rate of 9.7%. In a multivariable model including age, fms-like tyrosine kinase 3 (FLT3) status, and stem-cell transplantation (SCT), only the last two indicators remained significant: FLT3-ITD mutation (hazard ratio [HR]=4.6, p<0.001) and SCT (HR=0.43, p=0.01). CONCLUSION: In our analysis, there were no significant differences between the chosen regimens. High rates of early toxicity were found, emphasizing the role of supportive care and judicious selection of patients who are eligible for intensive salvage therapy in this setting. The FLT3-ITD mutation and SCT remained significant factors for survival in our study, in line with the results of previous studies.

Abstract Background Diffuse large B-cell lymphoma, among non-Hodgkin lymphomas, is one of the most frequent subtypes. Clinical laboratory data and post-treatment outcomes are scarce in the Brazilian population. Objective The main objective of this retrospective study was to assess the impact of tumor markers, including the Myeloid differentiation primary response 88 (MYD88) mutation. Method Eighty-three patients were included and treated with R-CHOP or R-CHOP-like regimens. Results Median age was 64-years old and 58% were female patients. The median follow-up was 42 months. The progression free survival (PFS) at this time was 63% and overall survival (OS), 66%. In the patients with tumors expressing Myc proto-oncogene protein (MYC) and B-cell lymphoma 2 (BCL2), assessed by immunohistochemistry (IHC), known as dual protein expressers, median post-progression survival was 31 (15-45) months. An increased proliferative index were associated with a high rate of progression (hazard ratio 2.31 [95% confidence interval [1.05-5.12]; p = 0.04). The cell of origin (COO), identified by IHC, was not able to predict PFS (p = 0.76). The MYD88 L265P mutation was present in 10.8% (9/83) of patients and did not show a prognostic correlation. Conclusion In conclusion, the MYD88 mutation, although an important tool for diagnosis and a possible target drug, presented at a low frequency and was not a prognostic marker in this population.

OBJECTIVE: The goal of this study was to monitor imatinib mesylate therapeutically in the Tumor Biology Laboratory, Department of Hematology and Hemotherapy, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP). A simple and sensitive method to quantify imatinib and its metabolite (CGP74588) in human serum was developed and fully validated in order to monitor treatment compliance. METHODS: The method used to quantify these compounds in serum included protein precipitation extraction followed by instrumental analysis using high performance liquid chromatography coupled with mass spectrometry. The method was validated for several parameters, including selectivity, precision, accuracy, recovery and linearity. RESULTS: The parameters evaluated during the validation stage exhibited satisfactory results based on the Food and Drug Administration and the Brazilian Health Surveillance Agency (ANVISA) guidelines for validating bioanalytical methods. These parameters also showed a linear correlation greater than 0.99 for the concentration range between 0.500 µg/mL and 10.0 µg/mL and a total analysis time of 13 minutes per sample. This study includes results (imatinib serum concentrations) for 308 samples from patients being treated with imatinib mesylate. CONCLUSION: The method developed in this study was successfully validated and is being efficiently used to measure imatinib concentrations in samples from chronic myeloid leukemia patients to check treatment compliance. The imatinib serum levels of patients achieving a major molecular response were significantly higher than those of patients who did not achieve this result. These results are thus consistent with published reports concerning other populations.

BACKGROUND: Real time PCR has become the most common technique to monitor BCR-ABL transcript levels of patients treated with kinase inhibitors. The aim of this study was to evaluate BCR-ABL levels of chronic myeloid leukemia patients treated with imatinib in the chronic phase and correlate the response to therapy and event-free survival. METHODS: BCR-ABL levels were measured in peripheral blood cell samples using Real time PCR at diagnosis and then every 3 months after starting therapy with imatinib. Major molecular response was defined as a three-log reduction from the standardized baseline value. Major molecular response values were adjusted to international scale using a conversion factor of 1.19. The results are reported as a BCR-ABL/ABL ratio (%). RESULTS: Hematological, major cytogenetic and complete cytogenetic responses were achieved by 57 (95%), 45 (75%) and 38 (63%) patients, respectively. Twenty-four out of sixty patients achieved a major molecular response (40%) in a median time of 8.5 months. Overall survival and event free survival were higher for patients with (100%) versus patients without (77%) a complete cytogenetic response (p-value = 0.01) at 48 months. Patients with complete cytogenetic response and major molecular response had a higher event free survival compared to patients with complete cytogenetic response but without major molecular response (p-value = 0.007). CONCLUSION: In conclusion, the prognostic impact of achieving complete cytogenetic response and a major molecular response and also the importance of molecular monitoring in the follow-up of chronic myeloid leukemia patients were demonstrated.

Nos últimos dez anos, o tratamento da leucemia mielóide crônica (LMC) passou por uma grande mudança com a introdução da terapia alvo, onde o mesilato de imatinibe (MI) atua inibindo a atividade tirosina quinase do transcrito BCR-ABL produto este do cromossomo Filadélfia (Ph). Esta revolução terapêutica obrigou que técnicas moleculares, até então de uso restrito na oncohematologia, como a reação em cadeia da polimerase em tempo real (RQ-PCR), fossem necessárias para monitorar o sucesso terapêutico ou a detecção precoce da perda de resposta ao MI. Nesta revisão estão delineados, de forma resumida, os principais procedimentos quanto à monitoração dos pacientes com LMC em tratamento com o MI segundo o Consenso Brasileiro de LMC.

Treatment of chronic myeloid leukemia (CML) has changed since the introduction of imatinib mesylate (IM) 10 years ago. IM acts as a target therapy against the BCR-ABL gene by inhibiting its tyrosine kinase activity. This revolution in treating CML compels the introduction of molecular techniques, such as real time quantitative polymerase chain reaction (RQ-PCR) to monitor the response to IM by providing an accurate measurement of the degree to which the BCR-ABL transcript is reduced or an early detection of loss of response identified by a rising level of BCR-ABL. In this review, we summarize the Brazilian CML consensus regarding the main procedures used to monitor CML patients treated with IM.