Číslo abstraktu: p01
Autoři: MUDr. Jana Volejníková; RNDr. Milena Holzerová, Ph.D.; doc.MUDr. Dagmar Pospíšilová, Ph.D.; MUDr. Zbyněk Novák; Mgr. Jana Vrbková, Ph.D.; doc. MUDr. Marián Hajdúch, Ph.D.; prof. MUDr. Vladimír Mihál, CSc.; Prof. RNDr. Mgr. Marie Jarošová, CSc.
Great progress has been made in the diagnostics and treatment of childhood acute lymphoblastic leukemia (ALL) over the past decades. Despite the fact that „classical“ prognostic factors have been gradually replaced by molecular monitoring of treatment response, cytogenetics is an integral part of the ALL diagnostics and provides important prognostic information.
We retrospectively review results of cytogenetics and molecular cytogenetics in 86 children with ALL (77 with B-precursor ALL and 9 with T-ALL) diagnosed in Olomouc, Czech Republic between 1990 and 2007 and treated on consecutive protocols ALL-BFM 90, 95 and ALL IC-BFM 2002. G-banding, fluorescence in situ hybridization (FISH) and multicolor FISH (mFISH) were applied, including screening for three major aberrations - TEL/AML1, BCR/ABL1 and MLL rearrangements.
Results and conclusions
Cytogenetic examination was successful in 82 (97.6%) patients and chromosomal changes were detected by cytogenetics and FISH in 77/82 (93.9%) patients. Cytogenetic results included: pseudodiploidy (31 patients), high hyperdiploidy (23 patients), hyperdiploidy (13 patients), hypodiploidy (10 patients), normal karyotype (4 patients), near haploidy with 26 chromosomes (1 patient). t(12;21) was detected in 18 patients, t(9;22) in 2 patients and t(4;11) in 2 patients. Rare cytogenetic aberrations were found in 4 patients: complex translocations involving three and/or four chromosomes in 2 cases and dicentric chromosomes in 2 cases. Of note, only one of these patients is alive in first complete remission.
In conclusion, we demonstrate an exceptionally high success rate and abnormality detection rate of cytogenetic examination in our center. We emphasize the importance of a sufficient input of biological material (at least 1-3 ml of bone marrow aspirate). In general, advances in the field of cytogenetics utilizing array-based technologies and next generation sequencing (NGS) have uncovered additional submicroscopic DNA alterations affecting genes involved in hematopoiesis, tumor suppression, apoptosis and cell cycle regulation, such as IKZF1, CRLF2, PAX5, and FLT.
Supported by: NPU LO1304 and IGA UP 2015-001.
Datum přednesení příspěvku: 2. 12. 2015