Showing papers by "Stefan Faderl published in 1999"

The biology of chronic myeloid leukemia

Abstract: Chronic myeloid leukemia (CML) is a clonal myeloproliferative expansion of transformed, primitive hematopoietic progenitor cells. It involves myeloid, monocytic, erythroid, megakaryocytic, B-lymphoid, and occasionally T-lymphoid lineages.1 CML was the first human disease in which a specific abnormality of the karyotype — the Philadelphia (Ph) chromosome — could be linked to pathogenetic events of leukemogenesis.2 It was among the first neoplastic diseases in which therapy with a biologic agent (interferon) was found to suppress the leukemic clone and prolong survival.3 Although heterogeneous, CML is the best-characterized leukemia at a molecular level, and studies in recent years have helped to define further . . .

Chronic Myelogenous Leukemia: Biology and Therapy

Abstract: Chronic myelogenous leukemia is one of the best-studied malignant conditions in humans. Progress in the understanding of molecular pathways has led to increasingly targeted and effective treatments...

Hyper-CVAD Program in Burkitt's-Type Adult Acute Lymphoblastic Leukemia

Abstract: PURPOSE: To evaluate response and outcome with a front-line intensive multiagent chemotherapy regimen in adults with Burkitt's-type acute lymphoblastic leukemia (B-ALL). PATIENTS AND METHODS: From September 1992 to June 1997, 26 consecutive adults with newly diagnosed untreated B-ALL received hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD). Their median age was 58 years (range, 17 to 79 years), and 46% were ≥ 60 years. Patients received Hyper-CVAD alternated with courses of high-dose methotrexate and cytarabine. Granulocyte colony-stimulating factor and prophylactic antibiotics were administered for all eight planned courses. CNS prophylaxis alternated intrathecal methotrexate and cytarabine on days 2 and 7 of each course. RESULTS: Complete remission (CR) was obtained in 21 patients (81%). There were five induction deaths (19%). The median time to CR was 22 days (range, 15 to 89 days); 70% achieved CR within 4 weeks. The 3-year survival rate was 49% (± 11%); th...

Chronic myelogenous leukemia: Update on biology and treatment

Abstract: Chronic myelogenous leukemia (CML) is a myeloproliferative disorder that follows a characteristic clinical course in which a chronic phase of variable duration precedes an accelerated, and ultimately blastic, phase, which is generally fatal. This disorder results from a clonal expansion of transformed hematopoietic progenitor cells and includes myeloid, monocytic, erythroid, megakaryocytic, and lymphoid lineages. At the molecular level, CML is characterized by the bcr-abl fusion gene, which results from the reciprocal translocation t(9;22)(q34;q11), creating the Philadelphia (Ph) chromosome. Chronic myelogenous leukemia was the first human disease for which a specific karyotype abnormality was demonstrated and could be linked to pathogenetic events of leukemogenesis. The outlook for patients with CML has changed dramatically over the last decade. The median survival time of patients has doubled to 5 to 7 years, with up to 50% of patients alive at 5 years. This development is due to refinements in allogeneic stem-cell transplantation and growing expertise in the use of interferon-alfa (Intron A, Roferon-A), a biological agent that has been shown to suppress the leukemic clone and to prolong survival in patients with CML. This review provides a concise update of the biology of CML, as well as current therapeutic options and management strategies.

Caspase 2 and caspase 3 as predictors of complete remission and survival in adults with acute lymphoblastic leukemia.

Abstract: Dysregulation of apoptosis is an important mechanism in leukemogenesis. Caspases are cysteine proteases that play a major role in the activation of apoptotic pathways and chemotherapy-induced cell death. High levels of inactive, uncleaved caspase 2 and caspase 3 have recently been associated with poor survival in patients with acute myelogenous leukemia. We hypothesized a similarly significant role for caspase 2 and caspase 3 in patients with acute lymphoblastic leukemia. We determined levels of uncleaved caspase 2 and caspase 3 by quantitative Western blot analysis in peripheral blood samples of 45 adults with newly diagnosed ALL. We evaluated patient prognostic variables and caspase levels using multivariate logistic and Cox regression models to determine their impact on complete remission rate and overall survival probability. Levels of caspase 2 and, to a lesser degree, caspase 3 were highly associated with cytogenetic abnormalities, with lower levels in the diploid group (P = 0.016 and P = 0.10, respectively). No association between either caspase level and the percentage of bone marrow blasts was found. A high level of caspase 3 (>0.37 as determined graphically) was significantly associated with achieving complete remission (CR; P = 0.006). A multivariate logistic regression analysis including age, WBC count, percentage of peripheral and marrow blasts, hemoglobin, albumin, lactate dehydrogenase, bilirubin, and creatinine determined that a high level of caspase 3 was the most significant predictor of CR (P = 0.025, adjusted), with albumin the only other significant variable (P = 0.031). Caspase 2 levels were not associated with probability of CR. In a multivariate Cox model for survival, however, levels of caspase 2 above 0.37 were associated with a lower survival probability than were levels below that threshold (P = 0.064). High levels of caspase 3 may have a significant effect on achieving CR. Because of the limited power (n = 45) of our study, the significance of caspase 2 and caspase 3 on overall survival remains to be validated by further investigations.

The Prognostic Significance of p16 INK4a /p14 ARF and p15 INK4b Deletions in Adult Acute Lymphoblastic Leukemia

Abstract: Cytogenetic/molecular abnormalities significantly influence the prognosis of patients with acute leukemia. Recently, two genes, p16 INK4a and p15 INK4b , encoding two cyclin-dependent kinase inhibitor proteins of the INK4 family of M r 15,000 and 16,000, respectively, have been localized to 9p21. Remarkably, the p16 INK4a locus has been found to encode a second protein, p14 ARF , known as p19 ARF in mice, with a distinct reading frame. Like p16 INK4a , p14 ARF is involved in cell cycle regulation, blocking cells at the G 1 restriction point through the activity of MDM-2 and p53. We studied bone marrow samples of 42 newly diagnosed and untreated patients with acute lymphoblastic leukemia for the incidence of deletions of p16 INK4a / p14 ARF and p15 INK4b using Southern blot analysis and determined the clinical outcome with regard to complete remission (CR) duration, event-free survival, and overall survival. We found deletions of p16 INK4a / p14 ARF in 17 of 42 patients (40%), with homozygous deletions in 11 of 42 patients (26%) and hemizygous deletions in 6 of 42 patients (14%). The gene for p15 INK4b was codeleted in most, but not all, cases and was never deleted without deletion of p16 INK4a / p14 ARF . No correlation was observed between molecular studies and karyotype abnormalities as determined by conventional cytogenetics. Furthermore, no difference was found in the CR rate, CR duration, event-free survival, and overall survival in patients with homozygous gene deletions compared to patients with no deletions or loss of only one allele.

Deletions and losses in chromosomes 5 or 7 in adult acute lymphocytic leukemia: incidence, associations and implications.

Abstract: Deletions or losses in chromosomes 5 or 7 are recurrent non-random abnormalities in acute myeloid leukemia (AML), and are associated with prior exposure to carcinogens or leukemogenic agents, and with poor prognosis. Their occurrence and significance in adult acute lymphocytic leukemia (ALL) is not well described. The aim of the study was to evaluate the incidence, associations and implications of chromosome 5 or 7 abnormalities in adult ALL. Patients with newly diagnosed ALL referred to MD Anderson Cancer Center between 1980 and 1996 were analyzed. Characteristics and outcome of patients with or without chromosome 5 or 7 abnormalities were compared by standard statistical methods. Thirty-one of 468 patients (6.6%) had chromosome 5 or 7 abnormalities. Loss of chromosome 5 occurred in six cases, three of them had both chromosome 5 and 7 abnormalities. Deletion or loss of chromosome 7 occurred as a single abnormality in three patients; in 28 patients it was associated with other abnormalities. The most significant cytogenetic association was with the Philadelphia chromosome (Ph) abnormality occurring in nine patients (29%). Compared with patients without the abnormalities, patients with chromosome 5 or 7 abnormalities tended to express CD34 more frequently (74% vs 54% P = 0.07), to be older (age >60 years 29% vs 18% P = 0.14), and to be associated with Ph (29% vs 11% P = 0.004). With therapy, the complete response (CR) rate with chromosome 5 or 7 abnormalities was lower (64% vs 79% P = 0.038) but the survival rate was similar (3-year survival rate 32% vs 36% P = 0.14). When the 22 patients without Ph were considered separately, the CR and survival rates were similar among patients with or without chromosome 5 or 7 abnormalities. Abnormalities in chromosome 5 or 7 are not specific for AML, and may occur in ALL. Unlike in AML, chromosome 5 or 7 abnormalities in ALL were not predictive of worse prognosis, which is accounted for mostly by the association with Ph.

Minimal residual disease in hematologic disorders.

Abstract: In almost no other area of medical oncology has the introduction of new drugs, combinations of chemotherapeutic agents, and novel biologic treatments caused such dramatic responses as it has in the treatment of malignant hematologic disorders. However, despite some therapeutic success, many patients relapse and die from recurrence of their disease. The implications of minimal residual disease (MRD), a term referring to disease that is undetectable by conventional morphologic methods, have therefore attracted increasing attention in recent years. New and powerful laboratory tools such as polymerase chain reaction assays have extraordinary sensitivity and provide exciting new insights into the detection, nature, quantification, and kinetics of MRD. This article summarizes methods used in the identification of MRD and its importance as exemplified in the case of acute leukemias and chronic myelogenous leukemia.