The prognostic impact of 17p (p53) deletion in 2272 adults with acute myeloid leukemia.

Loss of p53 -- a tumor suppressor gene located on the short arm of chromosome 17 (band 17p13.1) -- was detected in 105 out of 2272 (5%) adult acute myeloid leukemia (AML) patients who took part in the Study Alliance Leukemia AML96 and AML2003 multi center trials. There were 85 patients with 17p (p53) deletion with multiple aberrations and 20 patients with a 17p (p53) deletion as single aberration or with only one additional chromosomal abnormality. None of the p53-deleted patients displayed additional low-risk aberrations, like t(8;21) or inv(16). Significant positive association between p53 deletion and other high-risk factors was identified for del(5q) (P<0.001), -5 (P<0.001) and -7 (P<0.05). The molecular risk factors FLT3-ITD and NPM1 mutation showed an inverse correlation to the p53 deletion in complex aberrant patients (P<0.001). The multivariate analysis revealed p53 deletion without multiple aberrations as an independent negative prognostic factor for disease-free survival (P<0.001), relapse risk (P=0.028) and overall survival (P<0.001). Thus, the single p53 deletion should be considered as a high-risk aberration for future risk-adapted treatment strategies in AML.

[Leucocytosis: etiology and diagnostic approach]. / Leukozytose: Ursachen und Differenzialdiagnostik.

Leucocytosis is frequently diagnosed in clinical practice. The first step in the diagnostic approach should be based on differentiation of the leucocyte subpopulations. Neutrophilic leucocytosis can be observed physiologically after physical or mental stress. Furthermore, almost all immune reactions due to infection, allergy or autoimmune diseases are associated with changes in the leucocyte populations. An elevation of white blood cells caused by acute or chronic leukemia, or malignant lymphoma is less frequent. For the diagnosis of hematological malignancies, bone marrow examinations and genetic analyses are necessary.

The prognostic value of Bcl-XL gene expression for remission induction is influenced by cytogenetics in adult acute myeloid leukemia.

BACKGROUND AND OBJECTIVES: There is growing evidence that altered expression of genes belonging to the BcL-2 family of apoptosis regulators might influence chemotherapy-induced apoptosis in malignant cells and therefore could confer multidrug resistance. So far expression studies of apoptosis-regulating genes on acute myeloid leukemia (AML) have mainly focused on Bcl-2 itself and most of them have not included other factors involved in drug resistance or apoptosis as parameters determining response to chemotherapy, disease progression and survival. DESIGN AND METHODS: We therefore examined Bcl-2, Bcl-XL and Bax gene expression in 235 adult patients with de novo or secondary myeloid leukemia. The expression levels were correlated with established prognostic factors such as age, cytogentic aberrations, mdr1 gene expression and clinical outcome in a multivariate analysis. RESULTS: Bcl-2 and Bcl-XL positive patients had a much lower white blood cell count than negative patients (p<0.001 and p=0.003, respectively). Bcl-2 expression correlated with FAB subtype M0 (p=0.03), Bax with M5b (p=0.02) and Bcl-XL with M6 (p=0.005). Mdr1 expression was more frequently seen in Bcl-2 and Bcl-XL positive patients (p=0.03 and p=0.02, respectively). Remarkably Bax was significantly less frequently expressed in de novo AML patients with high risk cytogenetics (p=0.007). No difference in expression was recognized for Bcl-2 or Bcl-XL when statistical analyses were done for cytogenetic risk groups. However, in the multivariate analysis regarding the group of de novo AML patients < or =60 years with intermediate risk cytogenetics, Bcl-XL expression was found to be an independent negative prognostic factor for response to induction therapy (p=0.04). In contrast, no prognostic impact of Bcl-XL expression on treatment response was seen within the group of patients with high risk cytogenetic findings. Neither Bcl-2 nor Bax nor Bcl-XL expression had a significant influence on overall or disease-free survival. INTERPRETATION AND CONCLUSIONS: These data indicate that the prognostic value of Bcl-XL gene expression for treatment response in AML patients < or =60 years is dependent on cytogenetics.

Early allogeneic blood stem cell transplantation after modified conditioning therapy during marrow aplasia: stable remission in high-risk acute myeloid leukemia.

Two patients with high-risk acute myeloid leukemia (AML) whose bone marrow aspirates showed more than 25% blasts between 2 and 4 weeks after the first induction chemotherapy immediately received modified conditioning therapy with intravenous busulfan at 50% of the usual dose and fludarabine, before hematologic recovery occurred. Unmanipulated G-CSF mobilized peripheral blood stem cells from an HLA-identical sibling donor were transfused and haematopoietic recovery was achieved in both recipients. Both of them are in continuing hematological remission with full donor chimerism 12 and 22 months after transplantation. Early treatment intensification with allogeneic cell therapy during marrow aplasia might cure high-risk AML patients who are unlikely to achieve remission with conventional chemotherapy protocols.

Mutations in ras proto-oncogenes are associated with lower mdr1 gene expression in adult acute myeloid leukaemia.

Mutations in ras genes have been found to be the most frequent genetic aberrations in adult myeloid leukaemia (AML). Some reports have shown an improved outcome of ras-mutated AML. In order to understand the biology of ras mutation in AML, we studied a cohort of patients treated in a prospective multicentre trial for ras mutational status and resistance gene expression. Blast samples from 162 adult patients with de novo or secondary AML were examined for resistance gene expression (mdr1, mrp1 and lrp) and ras mutations using reverse transcription-polymerase chain reaction and protein nucleic acid-competitive polymerase chain reaction strategies respectively. Ras mutations were confirmed using DNA sequencing. Ras mutations leading to an exchange of amino acids were found in 40 (25%) patients. Thirty AML patients had N-ras mutations and nine patients had K-ras mutations. One patient showed both N-ras and K-ras mutations. Resistance gene expression was positive for mdr1 in 30%, for mrp1 in 43% and for lrp in 62% of patients. There was a strong inverse correlation between the presence of ras mutation and mdr1 expression (P = 0.005). However, no significant difference was seen between patients with or without ras mutations and mrp1 or lrp expression. Whereas mdr1 expression was associated with a lower complete remission rate (P < 0.04), ras mutations had no significant influence on remission status. Neither ras mutation nor mdr1 expression had a significant impact on overall or disease-free survival to date. For the first time, there is evidence that activated ras genes are associated with lower mdr1 expression in AML.

Comparison of spectral karyotyping and conventional cytogenetics in 39 patients with acute myeloid leukemia and myelodysplastic syndrome.

Spectral karyotyping (SKY) was performed in patients with acute myeloid leukemia (AML; n = 25), secondary AML (s-AML; n = 7), myelodysplastic syndrome (MDS; n = 6) and s-MDS (n = 1) to complement conventional cytogenetic investigations. According to the results of conventional cytogenetics the patients were subdivided into three groups: group 1, normal karyotype, n = 19 cases, median age = 64 years; group 2, patients displaying either one or two single aberrations, n = 10 cases, median age = 54 years; group 3, patients with > or =3 independent aberrations, n = 10 cases, median age = 61.5 years. SKY identified no abnormal metaphases in group 1. In one patient of group 2 a hidden translocation t(7;14)(q3?1;q2?2) could be revealed with SKY. Conventional cytogenetics had only shown trisomy 8. A similar t(7;14) was also detected in one patient of group 3. SKY was helpful for the delineation of marker chromosomes and additional material. Furthermore, SKY could distinguish between partial and total monosomies or real existing and apparent deletions. The combination of G-banding, FISH and SKY was found very useful for the precise delineation of the karyotype. As a result of our study we recommend SKY investigation as an important additional tool for accurate chromosome analysis. The detected t(7;14) might represent a novel recurrent translocation in acute myeloid leukemias.

Underestimation of inversion (16) in acute myeloid leukaemia using standard cytogenetics as compared with polymerase chain reaction: results of a prospective investigation.

In order to determine whether the polymerase chain reaction (PCR) is more suitable for the detection of inversion (16) as compared with standard cytogenetics, we prospectively investigated a total of 132 cases of de novo acute myeloid leukaemia (AML) (n = 121) and secondary AML after myelodysplastic syndromes (MDS) (n = 11) using a sensitive and nested PCR procedure to detect the fusion transcripts CBFbeta-MYH11. All patients were recruited within 10 months in an ongoing multicentre AML-trial. In addition, several cases from a retrospective molecular analysis were included. The data were compared with standard cytogenetics performed in a central laboratory. Of the 132 prospective AML cases, five patients (3.7%) harboured inv(16) upon conventional cytogenetics. In all cases fusion transcripts CBFbeta-MYH11 were detected using PCR. In addition in two patients fusion transcripts were detected, although cytogenetics revealed a normal karyotype. In the group of patients analysed retrospectively, four patients harboured fusion transcripts specific for CBFbeta-MYH11; cytogenetics were normal in one case, and could not be evaluated in two cases. These data show that PCR may be a better means to detect inv(16) in AML. Since inv(16) may have prognostic impact in AML, detection of this aberration seems important in the clinical management of AML patients.