Nodular lymphocyte predominant Hodgkin lymphoma: Experience of Polish Pediatric Leukemia/Lymphoma Study Group.

Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL) is a rare clinical entity. To investigate NLPHL clinical course and treatment a survey was performed within Polish Pediatric Leukaemia/Lymphoma Study Group (PPLLSG) participating centers. A questionnaire was sent to all participating centers and analysis of clinical data was performed. From 2010 to 2019, 19 pediatric patients with confirmed NLPHL were registered in Poland. Median age of patients was 12.2 (5.5 - 17.8) years. NLPHL occurred mainly in males (n = 17). Most of the patients (n = 16) had early stage disease - Stage I (n = 6) and stage II (n = 10). Four of the six patients with stage I disease (I A, n = 5; I B, n = 1) underwent complete primary resection. One of these relapsed and was treated with CVP (cyclophosphamide, vinblastine, prednisone) chemotherapy. Two other patients who were not resected completely received CVP chemotherapy and no relapses were observed. Thirteen patients presented with unresectable disease. Of these, eight received three CVP chemotherapy cycles, and five were treated with other chemotherapy regimens. Three relapses were observed and these patients were further treated with chemotherapy and rituximab. One patient underwent autologous stem cell transplantation (auto-SCT). All patients remain alive. Five-year progression-free survival and overall survival for the entire group of patients was 81.6% and 100%, respectively. NLPHL treatment results are consistent with results noted in other countries. Early stage patients have very good outcomes with surgery and observation or low intensity chemotherapy, but this approach may be insufficient in advanced disease.

Hounsfield units and fractal dimension (test HUFRA) for determining PET positive/negative lymph nodes in pediatric Hodgkin's lymphoma patients.

OBJECTIVES: We had developed a method that can help detect and identify lymph nodes affected by the neoplastic process. Our group evaluated the fractal dimension (FD) and X-ray attenuation (XRA) of lymph nodes in HL and compared to their metabolic activity as measured by 18F-FDG-PET examination. METHODS: The training set included 72 lymph nodes from 31 consecutive patients, and the tested set of 71 lymph nodes from next 19 patients. The measurement of FD of each lymph node was performed before the start of therapy using original software. X-ray attenuation (XRA) expressed in HU (Hounsfield Units) from CT scans was compared with the metabolic activity of the lymphatic nodes, measured by 18F-FDG-PET examination. RESULTS: Significant differences were observed between XRAmax and FDmax values in assessing the PET(+) and PET(-) nodes. All nodes were scored from 0 to 2. The HUFRA test properly qualified 95% with a score of 2 and 0 points as PET(+) or PET(-). CONCLUSION: The HUFRA test can differentiate about 70-80% of lymph nodes as PET(+) or PET(-) based solely on the CT examination. It can be useful in patients who were not subjected to 18FFDG-PET/CT examination before the treatment, or who had an unreliable result of 18F-FDG-PET/CT with further research requirements.

Hounsfield units from unenhanced 18F-FDG-PET/CT are useful in evaluating supradiaphragmatic lymph nodes in children and adolescents with classical Hodgkin's lymphoma.

BACKGROUND: The precise identification of the primarily-affected nodal regions in Hodgkin's lymphoma(HL) is essential in determining the stage of the disease and the intensity of chemotherapy and radiotherapy. OBJECTIVES: The aim of this study was to use the degree of X-ray attenuation (XRA) in Hounsfield units(HU) and the lymph node-to-muscle attenuation ratio (LN/M) in computed tomography (CT) unenhancedimaging, routinely performed with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET),to distinguish HL-affected supradiaphragmatic lymph nodes. MATERIAL AND METHODS: The study included 52 patients with classical HL treated according to the EuroNet-PHL-C1 protocol. Patients received 2 chemotherapy cycles after 18F-FDG-PET/CT testing, followedby re-examination. The lymph nodes were evaluated according to the Society for Pediatric Oncology andHematology's GPOH-HD-2002 study and Lugano criteria as not-involved (NI-LN) and involved (I-LN). RESULTS: A significant difference (p < 0.001) was found in the XRA and LN/M values between NI-LN andI-LN before treatment and after the 2 chemotherapy cycles. The optimal cut-off point for XRA (44.7 HU) andLN/M (0.79) values distinguishing I-LN from NI-LN nodes was determined by receiver operating characteristic(ROC) analysis. After 2 cycles of chemotherapy, higher XRA (p = 0.002) and LN/M (p = 0.001) values in thegroup with inadequate early CTx response were found. CONCLUSIONS: The use of XRA in HU and LN/M, together with the existing standard, can improve the qualificationof supradiaphragmatic lymph nodes in HL.

The BCL-2 protein in precursor B acute lymphoblastic leukemia in children.

The BCL-2 protein plays an important role in controlling apoptosis. Disorders of this process can lead to the emergence and development of acute lymphoblastic leukemia (ALL) and can determine the resistance of leukemic cells to chemotherapy. The levels of BCL-2 mRNA were determined in 20 children with pre-B ALL using RT-polymerase chain reaction and the percentage of BCL-2+ cells in 51 patients using flow cytofluorometry. Similar levels of BCL-2 mRNA (P=0.18) with a higher percentage of cells BCL-2+ (P=0.04) were shown in the bone marrow of patients with pre-B ALL compared to normal peripheral blood mononuclear cells. We could not find any connection between the level of BCL-2 mRNA or the percentage of BCL-2+ cells and selected clinical features. A high percentage of BCL-2+ cells and high levels of BCL-2 mRNA did not affect the 5-year overall survival probability nor the 5-year relapse-free survival probability. These results may indicate a high activity of mechanisms promoting the development of the final form of the BCL-2 protein from mRNA in leukemic cells. A high BCL-2 level does not affect the clinical course or worsen the prognosis in children with ALL.