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Biomedical subjects

M Schrappe

Publications and source records attributed to M Schrappe.

At least 73 records · Page 4Linked to original sources
PubMed2000

Secondary neoplasms subsequent to Berlin-Frankfurt-Münster therapy of acute lymphoblastic leukemia in childhood: significantly lower risk without cranial radiotherapy.

Secondary neoplasms (SNs) represent serious late complications after successful treatment of malignant diseases. To evaluate the rate and type of SNs after Berlin-Frankfurt-Münster (BFM) treatment in children with acute lymphoblastic leukemia (ALL), we analyzed the data from the BFM database and the German Childhood Cancer Registry (GCCR). Between April 1979 and April 1995, 5006 children with B-precursor or T-ALL were enrolled in 5 ALL-BFM multicenter trials. The median follow-up time from diagnosis was 5.7 years (range 1.5-18 years). By December 1997, 52 SNs were documented, including 16 acute myeloid leukemias (AMLs), 13 neoplasms of the central nervous system (CNS), and 23 other neoplasms. Compared with the expected numbers estimated from incidence rates derived from the GCCR, this represented a 14-fold increase for all cancers and a 19-fold increase for CNS tumors. SNs developed 0.9 to 15 years (median: 6 years) after the diagnosis of ALL; 46 patients were in first complete remission (CR). The overall cumulative risk of SNs at 15 years was 3.3% (95% confidence interval [CI]: 1.6%-5.1%) and 2.9% (95% CI: 1.6%-4.2%) in first CR. The risk was 3.5% (95% CI: 1.5%-5. 5%) after treatment, including cranial irradiation and significantly lower in nonirradiated patients: 1.2% (95% CI: 0.2%-2.3%; P =.048). The development of secondary AML was not associated with the use of any specific cytotoxic agent. Considering the high-survival rate of this large unselected ALL cohort, the risk of SN is relatively low, though higher, especially after cranial irradiation, than in the general population. Long-term follow-up is mandatory, and further SNs with longer latency periods are to be expected. (Blood. 2000;95:2770-2775)

Adolescent↗
PubMed2000

Outcome of treatment in children with Philadelphia chromosome-positive acute lymphoblastic leukemia.

BACKGROUND: Children with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) have a poor prognosis, and there is no consensus on the optimal treatment for this variant of ALL. METHODS: We reviewed the medical records of patients with Ph-positive ALL who were treated with intensive chemotherapy, with or without bone marrow transplantation, by 10 study groups or large single institutions from 1986 to 1996. Data on 326 children and young adults, who ranged in age from 0.4 to 19.9 years (median, 8.1), were analyzed to determine the rate of complete remission and the probability of event-free, disease-free and overall survival according to standard prognostic factors and type of treatment. RESULTS: The 267 patients who achieved a complete remission after induction chemotherapy (82 percent) were stratified into three subgroups according to the age and leukocyte count at the time of diagnosis: those with the best prognosis (a leukocyte count of less than 50,000 per cubic millimeter and an age of less than 10 years; 95 patients); those with an intermediate prognosis (intermediate-risk features; 92 patients); and those with the worst prognosis (a leukocyte count of more than 100,000 per cubic millimeter; 80 patients). The estimates of disease-free survival at five years (+/-SE) were 49+/-5 percent) for patients with the best prognosis), 30+/-5 percent (for those with an intermediate prognosis), and 20+/-5 percent (for those with the worst prognosis) (P<0.001 for the overall comparison). We also found that transplantation of bone marrow from an HLA-matched related donor offered significantly greater benefit than intensive chemotherapy alone in terms of protecting patients from relapse or other adverse events (relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.5; P<0.001). This finding was consistent in all three groups. CONCLUSIONS: Unlike the usual type of all, Ph-positive ALL is associated with a poor prognosis. Nevertheless, in some patients with favorable prognosis features, the disease can be be controlled by intensive chemotherapy. Transplantation of bone marrow from an HLA-matched related donor is superior to other types of transplantation and to intensive chemotherapy alone in prolonging initial complete remissions.

Adolescent↗
PubMed2000

Polymorphisms within glutathione S-transferase genes (GSTM1, GSTT1, GSTP1) and risk of relapse in childhood B-cell precursor acute lymphoblastic leukemia: a case-control study.

Glutathione S-transferases (GSTs) have been associated with outcome in human cancers treated with cytotoxic chemotherapy. In a case-control study, we investigated the association between polymorphisms within the GSTM1, GSTT1, and GSTP1 genes and risk of relapse in childhood acute lymphoblastic leukemia (ALL). Cases were relapsed patients. Controls were successfully treated patients with a minimum follow-up of 5 years. The null genotype (absence of both alleles) for GSTM1 or GSTT1 conferred a 2-fold (OR = 0.5, 95% CI = 0. 23-1.07, P =.078) and 2.8-fold (OR = 0.36, 95% CI = 0.13-0.99, P =. 048) reduction in risk of relapse, respectively, relative to the presence of the GSTM1 or GSTT1 gene. The GSTP1 Val(105)/Val(105) genotype showed a 3-fold decrease in risk of relapse (OR = 0.33, 95% CI = 0.09-1.23, P =.099) in comparison to the combined category of Ile(105)/Val(105) and Ile(105)/Ile(105 )genotypes. No particular associations with relapse were observed for the GSTP1 polymorphism at codon 114. The risk of relapse when having 1 of the low-risk genotypes (GSTM1 null, GSTT1 null, GSTP1 Val(105)/Val(105)) decreased 1.9-fold (OR = 0.53, 95% CI = 0.24-1.19, P =.123), and the risk when having 2 or 3 low-risk genotypes 3.5-fold (OR = 0.29, 95% CI = 0.06-1.37, P =.118), compared with individuals having no low-risk genotype (P for trend =.005). Our results suggest that polymorphisms within genes of the GST superfamily may be associated with risk of relapse in childhood ALL. (Blood. 2000;95:1222-1228)

Adolescent↗
PubMed2000

Intensive ALL-type therapy without local radiotherapy provides a 90% event-free survival for children with T-cell lymphoblastic lymphoma: a BFM group report.

The purpose of our study was to investigate the efficacy of an acute lymphoblastic leukemia (ALL)-type treatment with moderate-dose, prophylactic cranial irradiation and without local radiotherapy for childhood T-cell lymphoblastic lymphoma (T-LBL). From April 1990 to March 1995, 105 evaluable patients, 1.1 to 16.4 years of age, with T-LBL were enrolled in study NHL-BFM 90 (non-Hodgkin's lymphoma-Berlin-Frankfurt-Munster 90). They received an 8-drug induction over 9 weeks followed by an 8-week consolidation including methotrexate (MTX) 5 g/m(2) x 4. Patients with stage I (n = 2) and II (n = 2) continued with maintenance therapy (6-mercaptopurine daily and MTX weekly, both orally) until a total therapy duration of 24 months. Patients with stage III (n = 82) and IV (n = 19) received an 8-drug intensification over 7 weeks and cranial radiotherapy (12 Gy for prophylaxis) after consolidation, followed by maintenance. Residual tumor after induction had to be resected. Patients received intensified chemotherapy if tumor regression on day 33 of induction was less than 70% or when vital residual tumor was present after the complete induction phase. With a median follow-up of 4.5 years, the estimated event-free survival at 5 years is 90% (95% confidence interval, 82%-100%). Events were 1 early death, 8 tumor failures, and 1 secondary acute myeloid leukemia. A total of 101 patients were evaluable for the speed of tumor response. Two patients received intensified therapy due to less than 70% tumor regression on day 33. Of 19 patients with tumor residues after induction, 2 relapsed as compared to 4 of 80 patients with complete tumor regression. We conclude that, with intensive ALL-type chemotherapy including moderate cumulative doses of anthracyclines 240 mg/m(2) and cyclophosphamide (3 g/m(2)) and moderate-dose prophylactic cranial irradiation but no local radiotherapy, an event-free survival rate of 90% can be achieved in childhood T-LBL. (Blood. 2000;95:416-421)

Adolescent↗
PubMed2000

[Do guidelines bring an improvement in the perioperative course? A study of perioperative antibiotic prophylaxis].

INTRODUCTION: Although the effectiveness of perioperative antibiotic prophylaxis is proven, it is not used adequately. The aim of this study was to evaluate whether hospital-based guidelines are useful tools to improve the management of perioperative antimicrobial prophylaxis. MATERIAL: In a retrospective study the actual quality of perioperative antibiotic prophylaxis as given by the criteria choice of drugs, dosage, timing, continuation and 2nd dose after > 3 h was evaluated. After information and establishment of adequate guidelines we started a prospective analysis to test compliance and rate of adequate prophylaxis. Differences were calculated according to the chi 2-test with P < 0.05 significance niveau. RESULTS: The percentage of cases in which antibiotics were indicated but not administered was reduced from 15.5% to 8.4%. Compared to the result of the retrospective analysis, the prospective study showed a significantly higher percentage of adequately administered antibiotics (35.7% vs. 63.5%). This was mainly due to the compliance with dosage recommendations and to the 2nd dose in longer surgical procedures. DISCUSSION: Guidelines lead to a significant improvement in perioperative antibiotic prophylaxis. To increase this effect, further approaches such as integration of guidelines into computer-based systems should be evaluated.

Anti-Bacterial Agents↗
PubMed2000

[Quality assurance in ENT tumor surgery].

BACKGROUND AND OBJECTIVE: Quality control is of special importance in head and neck oncology since the quality of medical care constitutes a vital parameter for the diseased patient. In contrast to other medical specialties, no quality assurance program for head and neck cancer patients has yet been established in Germany. Therefore, a survey was conducted to assess the quality assurance instruments that are in use today in otorhinolaryngology-head and neck (ORL-HNS) centers. PATIENTS AND METHODS: In a nationwide survey, questionnaires were sent out to 146 German ORL-HNS departments (the return rate was 75%). RESULTS: 56% of all departments apply dedicated quality assurance processes, and 38% have appointed a formal quality assurance officer. Interdisciplinary oncological conferences are held in the vast majority of all departments with the participation of radiation oncologists in 86 (78%), medical oncologists in 84 (76%), diagnostic radiologists in 82 (74%), and pathologists in 73 (66%). Morbidity-mortality conferences are held in seven departments (6%). A standardized follow-up of oncological patients is carried out in 95 units (86%), and 53 departments use computer-assisted data bases to organize their follow-up data (48%). A wide variety of documentation systems is in use throughout the country: 78 units (71%) offer formal follow-up to their oncological patients. CONCLUSIONS: This survey documents a wide-spread interest in quality assurance procedures. Many individual efforts are being undertaken. However, no uniform quality assurance or auditing system is currently in use in Germany nor is a commonly accepted data base available. The ability to offer oncological follow-up within the national social security system is generally considered indispensable for the maintenance of high-quality oncological care in ORL-HNS departments.

Germany↗
PubMed2000

Molecular detection of minimal residual disease is a strong predictive factor of relapse in childhood B-lineage acute lymphoblastic leukemia with medium risk features. A case control study of the International BFM study group.

The medium-risk B cell precursor acute lymphoblastic leukemia (ALL) accounts for 50-60% of total childhood ALL and comprises the largest number of relapses still unpredictable with diagnostic criteria. To evaluate the prognostic impact of minimal residual disease (MRD) in this specific group, a case control study was performed in patients classified and treated as medium (or intermediate)-risk according to the criteria of national studies (ALL-BFM 90, DCLSG protocol ALL-8, AIEOP-ALL 91), which includes a good day 7 treatment response. Standardized polymerase chain reaction (PCR) analysis of patient-specific immunoglobulin and T cell receptor gene (TCR) rearrangements were used as targets for semi-quantitative estimation of MRD levels: > or =10(-2), 10(-3), < or =10(-4). Twenty-nine relapsing ALL patients were matched with the same number of controls by using white blood cell count (WBC), age, sex, and time in first complete remission, as matching factors. MRD was evaluated at time-point 1 (end of protocol Ia of induction treatment, ie 6 weeks from diagnosis) and time-point 2 (before consolidation treatment, ie 3 months from diagnosis). MRD-based high risk patients (> or =10(-3) at both time-points) were more frequently present in the relapsed cases than in controls (14 vs 2), while MRD-based low risk patients (MRD negative at both time-points) (1 vs 18) showed the opposite distribution. MRD-based high risk cases experienced a significantly higher relapse rate than all other patients, according to the estimated seven-fold increase in the odds of failure, and a much higher rate than MRD-based low risk patients (OR = 35.7; P= 0.003). Using the Cox model, the prediction of the relapse-free interval at 4 years was 44.7%, 76.4% and 97.7% according to the different MRD categories. MRD-based risk group classification demonstrate their clinical relevance within the medium-risk B cell precursor ALL which account for the largest number of unpredictable relapses, despite the current knowledge about clinical and biological characteristics at diagnosis. Therefore, MRD detection during the first 3 months of follow-up can provide the tools to target more intensive therapy to those patients at true risk of relapse.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Long-term results of four consecutive trials in childhood ALL performed by the ALL-BFM study group from 1981 to 1995. Berlin-Frankfurt-Münster.

Four thousand, four hundred and forty eligible children of up to 18 years of age were treated in four consecutive trials between 1981 and 1995 with the treatment protocols of the Berlin-Frankfurt-Münster (BFM) study group for childhood acute lymphoblastic leukemia (ALL). The probability for event-free survival (pEFS) at 8 years improved from 65.8% in study ALL-BFM 81 to 75.9% in study ALL-BFM 90. The cumulative incidence of recurrences with CNS involvement was 10.1% and 9.3% in studies ALL-BFM 81 and 83, but was reduced to less than 5% in study ALL-BFM 90 (for isolated CNS relapses from 5.3% in study ALL-BFM 81 to 1.1% in study ALL-BFM 90). Four major findings were derived from this series of trials performed by 37 to 96 centers in Germany, Austria, and Switzerland: (1) Reintensification is a crucial part of treatment, even in low risk patients; (2) presymptomatic cranial radiotherapy can be safely reduced to 12 Gy, or even be eliminated if it is replaced by early intensive systemic and intrathecal methotrexate applied; (3) maintenance therapy given a total of 24 months from diagnosis provides a lower rate of systemic relapses than treatment for 18 months; (4) inadequate response to an initial 7-day prednisone window (combined with one intrathecal injection of methotrexate on day 1) defines about 10% of the patients with a very high risk of relapse. For patients with adequate early response (90% of all) an 8-year pEFS of 80% has been achieved in the most recent trial ALL-BFM 90. While it has proven so far to be impossible to improve the outcome for the small group of high risk patients, the number of recurrences could be effectively reduced for the large group of patients responding adequately to the prednisone in vivo sensitivity test. Apart from inadequate prednisone response, patients with hyperleukocytosis, age <1 year, or the presence of the Philadelphia-chromosome (Ph+ ALL) are at a particularly high risk of failure.

Adolescent↗
PubMed2000

No evidence for a major role of heterozygous deletion 657del5 within the NBS1 gene in the pathogenesis of non-Hodgkin's lymphoma of childhood and adolescence.

Nijmegen breakage syndrome (NBS) is an autosomal recessive DNA repair disorder with a high predisposition for lymphoid malignancies. The majority of NBS patients carry a homozygous founder mutation (657del5) within the NBS1 gene. The observation of a high incidence of cancer in close relatives of NBS patients suggests a potential pathogenetic role of NBS1 mutations in heterozygotes as well. We assessed the frequency of the 657del5 mutation in 109 paediatric patients with non-Hodgkin's lymphoma (NHL). None of the patients analysed carried a NBS1 allele with the 657del5 mutation, suggesting that this mutation does not play a major role in the pathogenesis of NHL of childhood and adolescence.

Adolescent↗
PubMed2000

Constitutive expression levels of CD95 and Bcl-2 as well as CD95 function and spontaneous apoptosis in vitro do not predict the response to induction chemotherapy and relapse rate in childhood acute lymphoblastic leukaemia.

CD95 (Fas/APO-1) expression and function and Bcl-2 expression, as well as spontaneous apoptosis in vitro, have been shown to be predictive markers for the in vivo response to chemotherapy in acute myeloid leukaemia (AML). To determine the clinical significance of apoptosis-regulating factors in acute lymphoblastic leukaemia (ALL), we investigated cell samples of children with ALL who had been included in the German ALL Berlin-Frankfurt-Münster (BFM) study using flow cytometry for constitutive expression levels of CD95 (n = 110) and Bcl-2 (n = 110). Furthermore, we determined the extent of spontaneous apoptosis in vitro (n = 102) and susceptibility to anti-CD95-induced apoptosis (CD95-sensitivity) (n = 97). We correlated these findings with the functional activity of the multidrug resistance (MDR)-associated P-glycoprotein (P-gp), as detected by the rhodamine123 efflux test, immunophenotype, cytogenetics and clinical data of the patients examined. Good responders to initial prednisone therapy ('prednisone response') revealed significantly higher Bcl-2 expression levels [5.4 +/- 3.4 relative fluorescence intensity (RFI), n = 68] than poor responders (3.7 +/- 2.6 RFI, n = 42; P = 0.002). There was no significant correlation between the other investigated parameters and prednisone response. Moreover, neither the CD95 and Bcl-2 expression levels nor the extent of spontaneous apoptosis in vitro, CD95 sensitivity or P-gp function were correlated with the response to induction chemotherapy or relapse rate, either for B-cell precursor ALL or T-cell ALL. No consistent pattern of change in CD95 (n = 10) and Bcl-2 expression (n = 9) was noted in cases studied at both initial diagnosis and relapse. In conclusion, our findings underline the different cell biological features of primary AML and ALL cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Pegylated asparaginase (Oncaspar) in children with ALL: drug monitoring in reinduction according to the ALL/NHL-BFM 95 protocols.

Hypersensitivity reactions are relevant adverse effects of asparaginase therapy. Therefore, children treated with native Escherichia coli asparaginase in induction therapy of acute lymphoblastic leukaemia (ALL) or non-Hodgkin's lymphoma (NHL) were switched to the pegylated enzyme for reinduction under drug monitoring. Seventy children, including four patients with allergic reactions during induction, were given one dose of Oncaspar 1,000 U/m2 intravenously. Activity was determined every third or fourth day until it dropped below the limit of quantification. In current reinduction protocols [ALL/NHL-Berlin-Frankfurt-Münster (BFM) 95 trials], four doses of 10,000 U/m2 E. coli asparaginase deplete asparagine for about 2-3 weeks, therefore activities of >/= 100 U/l up to day 14 and >/= 50 U/l up to day 21 were targeted. In 66 patients without an allergic reaction during induction, the mean activity was 606 +/- 313 U/l, 232 +/- 211 U/l and 44 +/- 50 U/l after 1, 2 and 3 weeks respectively. In 44/66 patients, activity was >/= 100 U/l after 14 d. A rapid decline in activity was seen in the remaining 22 patients, including 8/22 patients who showed no activity after 1 week. Toxicity was low and comparable to the native enzymes but, in contrast to about 30% of hypersensitivity reactions with conventional reinduction therapy, no allergic reaction was seen. Substituting 4 x 10,000 U/m2 asparaginase medac for one dose of 1,000 U/m2 Oncaspar was safe and well tolerated. Comparable pharmacokinetic treatment intensity was achieved in about two-thirds of patients.

Adolescent↗
PubMed2000

Effective treatment of infantile choriocarcinoma in the liver with chemotherapy and surgical resection: a case report.

Infantile choriocarcinoma of the liver is an extremely rare entity, and outcome has been fatal in almost all published cases. To the authors' knowledge, this is the first report on successful treatment with preoperative chemotherapy. A 10-week-old girl presented with a large liver tumor, ovarian cysts, cardiac insufficiency, progressive hemolytic anemia, and thrombocytopenia. Ultrasound scan and magnetic resonance tomography (MRT) showed the typical pattern of infantile hemangioendothelioma. An emergency laparotomy was performed because of increasing cardiac insufficiency with ligation of the right hepatic artery, tumor biopsy, and subtotal resection of the ovarian cysts. Histology findings showed a choriocarcinoma of the liver and corpus luteum cysts of the ovaries. Serum beta-human chorionic gonadotropin (beta-HCG) was elevated to 1.600.00 U/L. Chemotherapy was initiated with etoposide and cisplatin. When x-ray examination showed development of lung metastases, chemotherapy was intensified with etoposide, cisplatin, and ifosfamid according to the German Study Group of Extracranial Nontesticular Malignant Germ Cell Tumors in Childhood and Adolescence (MAKEI-96). Serum beta-HCG levels decreased further, ultrasound examination showed significant tumor reduction, and pulmonal metastasis could no longer be found in chest x-rays. After the fourth course, a complete tumor resection was achieved by an extended right hemihepatectomy with adjuvant chemotherapy being administered after the operation. The child has been in complete remission for 22 months. The authors' experience shows that chemotherapy is effective for preoperative tumor reduction.

Choriocarcinoma↗
PubMed2000

Polymorphisms within glutathione S-transferase genes and initial response to glucocorticoids in childhood acute lymphoblastic leukaemia.

In children with acute lymphoblastic leukaemia (ALL) treated according to protocols of the Berlin-Frankfurt-Münster (BFM) study group, the initial response to prednisone is the strongest predictor of therapy outcome. Glutathione S-transferases (GSTs) have been implicated in glucocorticoid resistance. In order to assess a potential association of phenotypically relevant GST polymorphisms with prednisone response in childhood ALL, we conducted a case-control study of 45 prednisone poor-responders (cases) and 90 prednisone good-responders (controls) who were frequency matched according to initial white blood cell count. In addition, we analysed the association of GST genotypes with relapse of leukaemia. In univariate analysis, homozygous deletion of GSTT1 (null genotype) conferred a 6.7-fold reduction in risk of prednisone poor-response compared to individuals who were either heterozygous or homozygous for GSTT1 [odds ratio (OR) = 0.15, P = 0.071; multivariate odds ratio = 0.18, P = 0.117]. GSTM1 and GSTP1 genotypes did not show any association with prednisone response. In addition, risk of relapse was predicted strongest by the GSTT1 genotype. In univariate analysis, the GSTT1 null genotype conferred a 5.9-fold reduction in risk of relapse compared to the heterozygous or homozygous presence of GSTT1 (OR = 0.17, P = 0.095; multivariate OR = 0.23; P = 0.173). No associations of the GSTM1 genotype with risk of relapse were observed. GSTP1 codon 105 and codon 114 polymorphisms were predominantely associated with central nervous system relapse. Our results add further support to the hypothesis that genetic polymorphisms within specific GST genes might be of clinical importance in childhood ALL.

Adolescent↗
PubMed2000

Clinical significance of P-glycoprotein expression and function for response to induction chemotherapy, relapse rate and overall survival in acute leukemia.

BACKGROUND AND OBJECTIVES: A multidrug-resistance (MDR) phenotype mediated by P-glycoprotein (P-gp) contributes to chemotherapy failure in acute leukemia. However, the exact prognostic significance of this resistance mechanism is still unclear, mostly due to methodologic problems in P-gp detection. We therefore investigated, whether P-gp expression levels or functional P-gp activity better predict response to induction chemotherapy, relapse rate and overall survival in acute leukemia. DESIGN AND METHODS: We examined cell samples of 121 adults with de novo acute myeloid leukemia (AML) and 102 children with newly diagnosed acute lymphoblastic leukemia (ALL) for P-gp expression and functional P-gp activity by flow cytometry. P-gp function was determined by the rhodamine 123 (rh123)-efflux test (AML n=121, ALL n=102) and P-gp expression levels using the P-gp specific monoclonal antibodies (moabs) MRK-16 (AML n=51, ALL n=31), 4.E3 (AML n=35, ALL n=32), or UIC-2 (AML n=68, ALL n=50). We correlated our findings with the immunophenotype, FAB morphology, cytogenetics and clinical data of the examined patients. RESULTS: P-gp expression levels as detected by MRK-16 and 4.E3 were very low and did not differ between AML and ALL as estimated using relative fluorescence intensity (RFI) values and D-values by Kolmogorow-Smirnov (KS) statistics. For moab UIC-2, P-gp expression levels were higher in AML than in ALL. Within AML, moab UIC-2 mainly reacted with myelomonocytic-differentiated leukemic cells of the FAB M4/5 subtypes. No correlation between P-gp expression levels as detected by MRK-16, 4.E3 or UIC-2 and the response to induction chemotherapy or relapse rate, both in AML and ALL, was observed. However, a prognostic impact of P-gp expression levels on overall survival in AML was seen for moab MRK-16. Moreover, within AML, P-gp function was higher in immature blast cells as defined by immunophenotype and FAB morphology and correlated with response to induction chemotherapy, relapse rate, overall survival as well as cytogenetic risk groups. In ALL, the overall functional P-gp activity was lower than in AML and did not correlate with immunophenotypical subgroups, response to induction chemotherapy, relapse rate or overall survival. INTERPRETATION AND CONCLUSIONS: Our data demonstrate a prognostic impact of P-gp in AML but not ALL and indicate that the functional rh123-efflux assay should be preferred for flow-cytometric P-gp evaluation in acute leukemia compared with P-gp expression analysis by monoclonal antibodies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗