Actualización de resultados demográficos y terapéuticos de pacientes con Leucemia Mieloide Aguda no promielocítica en el Hospital Clínico de la Pontificia Universidad Católica de Chile / Acute myeloid leukemia. Analysis of 114 patients

BACKGROUND: Acute myeloid leukemia (AML) is the most common leukemia in adults. Aim: To Describe our population of patients with AML and report the outcomes of our treatments. MATERIAL AND METHODS: Review of electronic clinical records of 114 patients with AML with a median age of 57 years (59% men). Results: Seventeen percent of patients were classified as low risk, 38% as intermediate risk and 33% as high risk. Seventy-six percent of patients were treated with intensive chemotherapy. Five years overall survival according to cytogenetic risk was 59, 41, and 12% in low, intermediate, and high-risk patients, respectively. The outcomes were better in patients under 60 years. The median survival of patients treated with intensive chemotherapy aged less than 60 years and 60 years and above was 3.4 and 1 year, respectively. CONCLUSIONS: Our results are comparable to those reported in developed countries. Improving the survival of patients 60 years and older is our main challenge.

Banding and molecular cytogenetic studies detected a CBFB-MYH11 fusion gene that appeared as abnormal chromosomes 1 and 16 in a baby with acute myeloid leukemia FAB M4-Eo.

The acute myeloid leukemia (AML) subtype M4Eo occurs in 5% of all AML cases and is usually associated with either an inv(16)(p13.1q22) or a t(16;16)(p13.1;q22) chromosomal abnormality. At the molecular level, these abnormalities generate a CBFB-MYH11 fusion gene. Patients with this genetic alteration are usually assigned to a low-risk group and thus receive standard chemotherapy. AML-M4Eo is rarely found in infants. We describe clinical, conventional banding, and molecular cytogenetic data for a 12-month-old baby with AML-M4Eo and a chimeric CBFB-MYH11 fusion gene masked by a novel rearrangement between chromosomes 1 and 16. This rearrangement characterizes a new type of inv(16)(p13.1q22) masked by a chromosome translocation.

Inv(4)(p14q27) in a case with de novo acute nonlymphocytic leukemia.

An inversion, inv(4)(p14q27), was found as the sole karyotypic anomaly at diagnosis in the bone marrow cells from a 65-year-old male patient with an M4 acute nonlymphocytic leukemia (ANLL). To our knowledge, the breakpoints observed in this case appear to be different from other inversions of chromosome 4 previously described in ANLL. The patient we described had a poor response to chemotherapy and had a short survival.

Translocation (11;11)(p13- p15;q23) in a child with therapy-related acute myeloid leukemia following chemotherapy with DNA-topoisomerase II inhibitors for Langerhans cell histiocytosis.

We report a new case of therapy-related acute myeloid leukemia in a child with Langerhans cell histiocytosis. This patient was previously treated with a protocol of multidrug chemotherapy, containing a relatively low dose of etoposide (total dose of 900/m(2)). Twenty-six months after the end of the therapy, the patient returned to the hospital with fever and anemia. The white blood cell count was 53 x 10(9)/L. The bone marrow examination showed massive infiltration with French-American-British acute myeloid leukemia classification M4 blast cells. The patient did not respond to an intensive treatment with high dose ARA-C and idarubicin. He died 6 months later. The cytogenetic abnormality of the blast cells was a t(11;11)(p13 -15;q23), that has not been described before in a secondary leukemia case.

Implication of tyrosine kinase receptor and steel factor in cell density-dependent growth in cervical cancers and leukemias.

Cell-cell interaction is important in the expansion of leukemic cells and of solid tumors. Steel factor (SF) or Kit ligand is produced as a membrane-bound form (mSF) and a soluble form. Because both primary gynecological tumors and primary leukemic cells from patients with acute myeloblastic leukemia (AML) have been shown to coexpress c-Kit and SF, we addressed the question of whether mSF could contribute to cell interaction in these cancers. Investigations on primary cervical carcinomas have been hindered by the fact that the cells do not grow in culture. We report herein the establishment of two cervical carcinoma cell lines, CALO and INBL, that reproduce the pattern of SF/c-Kit expression observed in primary tumor samples. In addition, these cells exhibit marked density-dependent growth much in the same way as AML blasts. Using an antisense strategy with phosphorothioate-modified oligonucleotides that specifically target SF without affecting other surface markers, we provide direct evidence for a role of mSF and c-Kit in cell interaction and cell survival in these gynecological tumor cell lines as well as in primary AML blasts. Finally, our study defines the importance of juxtacrine stimulation, which may be as important, if not more, than autocrine stimulation in cancers.

Cytogenetic study of 50 de novo cases of ANLL from Argentina.

BACKGROUND AND METHODS: Consistent and specific chromosomal aberrations have been observed in an increasing number of neoplasias. In the present report, we describe the cytogenetic findings from 50 cases of de novo ANLL in Argentina, South America, studied at diagnosis. In addition, their relation with the FAB classification is analyzed. Children with Down's syndrome and secondary ANLL were excluded from this analysis. RESULTS AND CONCLUSIONS: Out of 50 banded cases studied, 11 (22%) had normal karyotype, while the remaining 39 (78%) presented abnormal metaphases with structural alterations in the majority of them. Chromosomes 7 and 22 were most frequently involved in numerical alterations in children, while chromosomes 6, 8, 14 and 16 were the ones most often involved in adults. Consistent chromosome rearrangements were observed and they were linked to specific cytomorphologic subsets. The translocations t(8;21) and t(15;17) were seen only in M2 and M3, respectively. The inversion of chromosome 16, inv(16), was a typical finding in M4, but was not restricted to this subtype. Translocation t(2;3) was observed in three cases, all M4, each with a variable chromosome pattern. These results are in accordance with cytogenetic findings in Western Europe and the USA.