Karyotypic and fluorescent in-situ hybridization study of the centromere of chromosome 7 in secondary myeloid neoplasms

BACKGROUND: Secondary myeloid neoplasms comprise a group of secondary diseases following exposure to myelotoxic agents or due to congenital diseases. The improvement of anticancer agents and immunosuppressive drugs seem to be associated with an increased incidence of secondary myeloid neoplasms. Karyotyping of bone marrow is essential for diagnosis and prognosis. Previous use of alkylating agents and radiation are associated with clonal abnormalities such as recurrent unbalanced -5/5q-, -7/7q- and complex karyotypes, whereas topoisomerase-II inhibitors lead to changes such as the balanced 11q23 rearrangement, t(8;21), t(15;17) and inv(16). OBJECTIVE: To study the clinical and cytogenetic data of patients with secondary myeloid neoplasms who took antineoplastic and/or immunosuppressive drugs or progressed from aplastic anemia. METHODS: The clinical and cytogenetic characteristics of 42 patients diagnosed with secondary myeloid neoplasms in one institution were retrospectively evaluated. Of these, 25, 11 and 6 patients had had oncological diseases, aplastic anemia and other diseases, respectively. Conventional cytogenetic and FISH analyses were performed for monosomy 7. RESULTS: The cytogenetic study was conclusive in 32 cases with 84.4 percent of clonal abnormalities. Monosomy 7 and complex karyotypes were present in 44.4 percent and 37 percent, respectively. A high prevalence of unbalanced abnormalities (96.3 percent) was observed. Monosomy 7 was more prevalent in patients with myelodysplastic syndromes/myeloid neoplasms after aplastic anemia (66.6 percent). The median survival after diagnosis of myeloid neoplasms was only 5.7 months. Normal cytogenetics was associated to better survival (p-value = 0.03). There was a slightly worse trend of survival for patients with complex karyotypes (p-value = 0.057). Abnormal karyotype was an independent risk factor for poor survival (p-value = 0.012). CONCLUSION: This study enhances the importance ...

Avaliação da citogenética convencional e molecular em portadores de leucemia promielocítica aguda no Serviço de Hematologia do Hospital das Clínicas da Faculdade de Medicina da USP / Conventional and molecular cytogenetics in patients with acute promyelocytic leukemia of the Hematology Service of Clinical Hospital of São Paulo Medical School

INTRODUÇÃO: A leucemia promielocítica aguda (LPA) é um subtipo distinto de leucemia mielóide aguda (LMA), caracterizado pela presença de um acúmulo de promielócitos anormais na medula óssea e/ou sangue periférico, riscos de coagulopatias e por alterações cromossômicas estruturais envolvendo sempre o locus gênico para o receptor alfa do ácido retinóico (RAR). Corresponde morfologicamente aos subtipos M3 e M3variante de LMA, segundo a Classificação Franco- Américo- Britânica (FAB) e ao subtipo de LMA associada à translocação recíproca e balanceada entre os cromossomos 15 e 17[t(15;17)] e variantes, segundo a classificação da Organização Mundial de Saúde. O curso clínico da LPA tem sido modificado, nos últimos anos, de uma leucemia aguda rapidamente fatal para um dos mais curáveis subtipos de LMA. A introdução de agentes terapêuticos que atuam diretamente na lesão molecular, como o ATRA e o Trióxido de Arsênico, teve grande impacto na sobrevida da LPA. A eficácia do tratamento é dependente do rearranjo genético presente nas células leucêmicas, o diagnóstico morfológico é sugestivo da alteração genética, devendo ser rapidamente confirmado por técnicas de citogenética molecular. MÉTODOS: Utilizando a citogenética convencional e molecular (FISH) com sondas de fusão para o rearranjo PML-RAR e de ruptura para o gene RAR, analisou-se 62 pacientes portadores de LPA, diagnosticados por estudo morfológico/imunofetípico no HC-FM/USP entre os anos de 1997 a 2006. RESULTADOS: Dos 62 pacientes analisados, 37 (59,7%) apresentaram a t(15;17)(q22;q21) visível no cariótipo; destes, 26 (42,0%) apresentaram a t(15;17) como anormalidade clonal isolada, 10 (16,1%) apresentaram outras alterações cromossômicas clonais em adição a t(15;17) e um paciente (1,6%) apresentou uma variante complexa da t(15;17)...

INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML), characterized by clonal expansion of myeloid precursors blocked at promyelocytic stage, risks of coagulopathy and presence of chromosomal translocations involving RAR (retinoic acid receptor ) gene. Corresponds to the M3 and M3variant subtypes of AML, according to the French-American-British (FAB) classification and the subtype of AML associated with balanced reciprocal translocation between chromosomes 15 and 17 [t (15; 17)] and variants, according to the World Health Organization classification. The clinical APL course has been changed in late years, from highly fatal to highly curable subtype of AML. The introduction of therapeutic agents that act directly on the molecular lesion, such as ATRA and arsenic trioxide, had a great impact on survival of APL. The efficacy of treatment is dependent on genetic rearrangement present in the leukemia cells, the morphologic diagnosis although predictive of the specific genetic lesion genetic, should be quickly confirmed by molecular techniques. METHODS: We analysed cytogenetics findings in 62 patients diagnosed as promyelocytic leukemia by morphological and immunophenotypic studies at the Hematology Service of Clinical Hospital of Sao Paulo Medical School from 1997 to 2006. For this, we used karyotype and FISH with PML-RARA fusion translocation and RARA break-apart probes. RESULTS: Of the 62 patients studied, 59.7% showed the t(15;17)(q22;q21) visible in the karyotype [42.0% had t(15;17) as the sole clonal abnormality, 16.1% showed other additional abnormalities and 1.6% had a complex variant of t(15;17)], 29% had the confirmation of the rearrangement PML-RAR through the FISH-fusion technique and 11.3% showed no break in RAR...