Cytogenetics in adult acute lymphocytic leukemia

Normal Absolute Monocyte Count at the Time of Relapse is Associated with Improved Survival After First Salvage Therapy in Adult Patients with Early Relapsed B-Lineage Acute Lymphoblastic Leukemia

Background

Peripheral monocytes, a key cell type for innate immunity, have been shown to be associated with survival in various types of hematological malignancies. However, no previous studies regarding the prognostic impact of peripheral absolute monocyte count (AMC) in early relapsed B-lineage acute lymphoblastic leukemia (B-ALL) have been reported.

Methods

Forty-nine cases of early relapsed adult B-ALL were reviewed. The upper (0.80 × 10⁹/L) and lower limits (0.12 × 10⁹/L) of the normal value for AMC were used as cut-off points. Kaplan–Meier curves and Log rank test were used for comparison of overall survival (OS). The univariate and multivariate Cox proportional hazards models were used for investigating the factors associated with OS.

Results

More than half (59.2%) of all patients showed a normal AMC (0.12–0.80 × 10⁹/L). The median follow-up was 5.3 months from the start of first salvage therapy. Univariate analysis revealed that normal AMC (versus low/high AMC) at the time of relapse was a prognostic factor for improved OS (P = 0.021). On multivariate analysis, normal AMC (versus low/high AMC) at the time of relapse remained an independent prognostic factor for improved OS (hazard ratio = 0.43, P = 0.030).

Conclusion

AMC at the time of relapse, which can be easily derived from routine clinical laboratory testing of complete blood count, might be used as a prognostic marker for survival outcomes in adult patients with early relapsed B-ALL.

Prognostic significance of leukopenia during the induction phase in adult B cell acute lymphoblastic leukemia

The association between chemotherapy-induced leukopenia and clinical outcome has been reported for several types of cancer. The objective of the current study was to evaluate the association of chemotherapy-induced leukopenia during the induction phase with the clinical outcome of adult B cell acute lymphoblastic leukemia (B-ALL). Fifty-one cases of B-ALL, age ≥14 years, were reviewed. The variables under consideration included age, sex, the initial white blood cell (WBC) count (WBC-0), as well as the WBC counts on days 8 (WBC-8), 15 (WBC-15), and 22 (WBC-22) during induction therapy, early bone marrow responses on day 15 during induction therapy, immunophenotype, and cytogenetics. Univariate analysis revealed that WBC-15 ≥0.40×10⁹/L was significantly associated with inferior event-free survival (EFS) (hazard ratio [HR]=2.95, P=0.004) and overall survival (OS) (HR=2.92, P=0.015). On multivariate analysis, high WBC-15 (≥0.40×10⁹/L) remained an independent prognostic factor for EFS (HR=3.29, P=0.014) and OS (HR=3.29, P=0.038). Our results suggested that WBC-15 may contribute to refinements in the current risk stratification algorithms for adult B-ALL.

Cytogenetic Studies in T-Cell Acute Lymphoblastic Leukemia (1981 – 2002)

Chromosomal analysis was successfully performed in 34 of the 37 patients with T-cell acute lymphoblastic leukemia (ALL) seen at the University Hospital in Brest (France) between 1981 and 2002. A normal karyotype was observed in 29.4% of the patients. Numerical changes were rare, 79.2% of the abnormal karyotypes being pseudodiploid. All 24 abnormal karyotypes had at least a structural rearrangement. Translocations involving band 14q11, that contains the T-cell receptor (TCR) alpha and delta-genes, were observed in 8 patients; in 3 of them, a new partner chromosomal band was found. The short arms of chromosomes 11 and 12 were involved in 3 and 2 translocations respectively. Three patients had a del(6q). Our results are in agreement with those of the literature. Most of the recurrent abnormalities are different from those of B-lineage ALL. Some are known to involve TCR genes whereas others can lead to the discovery of new genes that are important to T-lineage leukemogenesis.

Adult acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) in adults is a relatively rare neoplasm with a curability rate around 30% at 5 years. This consideration makes it imperative to dissect further the biological mechanisms of disease, in order to selectively implement an hitherto unsatisfactory success rate. The recognition of discrete ALL subtypes (some of which deserve specific therapeutic approaches, like T-lineage ALL (T-ALL) and mature B-lineage ALL (B-ALL)) is possible through an accurate combination of cytomorphology, immunophenotytpe and cytogenetic assays and has been a major result of clinical research studies conducted over the past 20 years. Two-three major prognostic groups are now easily identifiable, with a survival probability ranging from <10 to 20% (Philadelphia-positive ALL) to about 50-60% (low-risk T-ALL and selected patients with B-lineage ALL). These issues are extensively reviewed and form the basis of current knowledge. The second major point relates to the emerging importance of studies that reveal a dysregulated gene activity and its clinical counterpart. It is now clear that prognostication is a complex matter ranging from patient-related issues to cytogenetics to molecular biology, including the evaluation of minimal residual disease (MRD) and possibly gene array tests. On these bases, the role of a correct, highly personalised therapeutic choice will soon become fundamental. Therapeutic progress may be obtainable through a careful integration of chemotherapy, stem cell transplantation, and the new targeted treatments with highly specific metabolic inhibitors and humanised monoclonal antibodies.

[Applications of molecular biology to care of patients with malignant hematological disease]

The improvement of the techniques of molecular biology allowed greater performances in the field of detection and characterization of chromosomal abnormalities and/or molecular defects observed in human hematological malignancies. Cytological and immunophenotypical results are reinforced by data obtained with standard and molecular cytogenetic tools and with PCR based techniques. Molecular data are usefull at diagnosis in order to define different types of leukemias and to score patient prognosis. Therefore, these techniques help to choose among various therapeutic options. In post induction treatment period, PCR tools allowed to measure minimal residual disease (MRD) and to distinguish new prognosis factors essential for patient's management.

Trisomy 4 as the sole cytogenetic abnormality in a patient with T-cell acute lymphoblastic leukemia

Trisomies as sole cytogenetic abnormalities are extremely rare in acute lymphoblastic leukemia (ALL). We describe here the clinical features and immunophenotyping, cytogenetic, and fluorescence in situ hybridization (FISH) findings in a T-cell ALL patient with trisomy 4 as the sole cytogenetic abnormality. The leukemic clone was positive for CD2, CD7, CD34, and terminal deoxynucleotidyl transferase (TdT); CD13 was weakly expressed. Data on the tracking of the leukemic clone with immunophenotyping, cytogenetic, and FISH studies are discussed. The present case is compared with the three previous reported cases of trisomy 4 in ALL. Due to the rarity of this cytogenetic abnormality, its prognostic significance in ALL remains unclear.

Hypodiploidy of 37 chromosomes in an adult patient with acute lymphoblastic leukemia

We present a 42-year-old man with acute lymphoblastic leukemia and hypodiploidy at diagnosis. Chromosome count was 37, with a mixture of numerical and structural abnormalities. The patient died 9 months post diagnosis, during which time three further cytogenetic tests were performed. The core abnormalities seen upon diagnosis were present at 7 and 9 months after diagnosis, with a duplication of the abnormal hypodiploid karyotype on the last specimen. While considerable imbalances were present as a result of whole chromosome aneuploidy, no region was obviously nullisomic.

A fluorescence in situ hybridization study of TEL-AML1 fusion gene in B-cell acute lymphoblastic leukemia (1984-2001)

Acute lymphoblastic leukemia (ALL) is associated with recurrent chromosomal abnormalities. The cryptic translocation t(12;21)(p13;q22), which leads to the TEL-AML1 fusion gene, is the most common abnormality in childhood B-cell ALL. The aim of this retrospective study was to determine the incidence of TEL-AML1 fusion in childhood and adult B-cell ALL using interphase fluorescence in situ hybridization (I-FISH) and its association with additional changes. FISH, using dual-color extra-signal (ES) DNA probe specific for the TEL and AML1 genes, was performed either on blast cells suspensions stored in liquid nitrogen immediately after Ficoll or on leukemic cells preserved in fixative solution at -20 degrees C after short-term culture. No TEL-AML1 fusion was observed in the 26 ALL adults. The fusion was found among 19.6% of the 57 ALL children, additional changes being identified by conventional cytogenetics in 80% of the cases. A deletion of the untranslocated TEL was observed in 36.3% of the ALL with the TEL-AML1 fusion. The coexpression of myelocytic and B-lymphoid antigens was found in 3 of the 11 of TEL-AML1 fusion positive-ALL. Our results (frequency of TEL-AML1 fusion in children and of the deletion of the untranslocated TEL allele, mean age of the patients and white blood cell count) are within the range observed by others. Structural chromosomal abnormalities other than the t(12;21) are frequent and may play a role in the prognosis of these patients.

Arsenic trioxide as effective therapy for relapsed acute promyelocytic leukemia

The standard of treatment for newly diagnosed patients with acute promyelocytic leukemia (APL) is all-trans retinoic acid (ATRA) plus anthracycline-based cytotoxic chemotherapy, a combination that is highly effective for remission induction. However, 20%-30% of patients relapse and require salvage therapy. Reports from China on the striking efficacy and safety of arsenic trioxide in patients with APL led to clinical trials in the United States, which culminated in U.S. Food and Drug Administration approval in September 2000. Trisenox (Cell Therapeutics, Inc., Seattle, WA) is an injectable formulation of arsenic trioxide indicated in the treatment of refractory or relapsed APL. The common side effects of Trisenox therapy are mostly mild and self-limiting and do not require interruption of therapy. Serious adverse effects that can occur include hyperleukocytosis, electrocardiographic abnormalities, and APL differentiation syndrome. These effects can be prevented or managed successfully with careful patient monitoring during treatment. Trisenox has no known cross-resistance with ATRA or other anticancer agents. It does not cause hair loss and is not myelosuppressive in patients with APL. Oncology nurses can play a major role in educating patients about this new drug, explaining its clinical benefits and side effects and the precautions that are necessary for its use.

Towards an integrated classification of adult acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) represents a biologically and clinically heterogeneous group of diseases characterized by the abnormal proliferation and accumulation of immature lymphoid cells within the bone marrow and lymphoid tissues. Following a diagnostic work-up, prognostic data are routinely achieved through physical examination, serum biochemical profiles, peripheral blood count and bone marrow morphology. Over the years, information obtained through karyotype, molecular genetics, extensive immunophenotype, multidrug resistance and, more recently, genomic profiling is progressively contributing to a better understanding of the biology of this complex disease, to the identification of subgroups of patients with a different clinical outcome, to the more precise monitoring of minimal residual disease, to the use of different therapeutic protocols based on prognostic indicators and, recently, also to the design of innovative and specific treatment strategies. In the present review, we will discuss how an integrated approach is now mandatory for the optimal management of adult ALL.