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Biomedical subjects

Markus Loeffler

Publications and source records attributed to Markus Loeffler.

7 recordsLinked to original sources
PubMed2004

Two-weekly or 3-weekly CHOP chemotherapy with or without etoposide for the treatment of elderly patients with aggressive lymphomas: results of the NHL-B2 trial of the DSHNHL.

Cyclophosphamide, doxorubicin, vincristine, and prednisone, given every 3 weeks (CHOP-21), is standard chemotherapy for aggressive lymphomas. To determine whether biweekly CHOP (CHOP-14) with or without etoposide is more effective than CHOP-21, 689 patients ages 61 to 75 years were randomized to 6 cycles of CHOP-21, CHOP-14, CHOEP-21 (CHOP plus etoposide 100 mg/m2 days 1-3), or CHOEP-14. Patients in the 2-weekly regimens received granulocyte colony-stimulating factor (G-CSF) starting from day 4. Patients received radiotherapy (36 Gy) to sites of initial bulky disease and extranodal disease. Complete remission rates were 60.1% (CHOP-21), 70.0% (CHOEP-21), 76.1% (CHOP-14), and 71.6% (CHOEP-14). Five-year event-free and overall survival rates were 32.5% and 40.6%, respectively, for CHOP-21 and 43.8% and 53.3%, respectively, for CHOP-14. In a multivariate analysis, the relative risk reduction was 0.66 (P =.003) for event-free and 0.58 (P <.001) for overall survival after CHOP-14 compared with CHOP-21. Toxicity of CHOP-14 and CHOP-21 was similar, but CHOEP-21 and in particular CHOEP-14 were more toxic. Due to its favorable efficacy and toxicity profile, CHOP-14 should be considered the new standard chemotherapy regimen for patients ages 60 or older with aggressive lymphoma.

Aged↗
PubMed2004

Two-weekly or 3-weekly CHOP chemotherapy with or without etoposide for the treatment of young patients with good-prognosis (normal LDH) aggressive lymphomas: results of the NHL-B1 trial of the DSHNHL.

The combination of cyclophosphamide, doxorubicin, vincristine, and prednisone, given every 3 weeks (CHOP-21) is standard chemotherapy for aggressive lymphomas. To determine whether CHOP given every 2 weeks (CHOP-14) or the addition of etoposide (CHOEP-21, CHOEP-14) can improve results in patients ages 18 to 60 years with good prognosis (normal lactic dehydrogenase [LDH] level), 710 patients were randomized to 6 cycles of CHOP-21, CHOP-14, CHOEP-21 (CHOP plus etoposide 100 mg/m2 days 1-3), or CHOEP-14 in a 2 x 2 factorial study design. Patients in the biweekly regimens received granulocyte colony-stimulating factor (G-CSF) starting from day 4. Patients received radiotherapy (36 Gy) to sites of initial bulky disease and extranodal disease. CHOEP achieved better complete remission (87.6% versus 79.4%; P =.003) and 5-year event-free survival rates (69.2% versus 57.6%; P =.004, primary end point) than CHOP, whereas interval reduction improved overall survival (P =.05; P =.044 in the multivariate analysis). Although the CHOEP regimens induced more myelosuppression, all regimens were well tolerated. CHOEP should be the preferred chemotherapy regimen for young patients with good-prognosis (normal LDH level) aggressive lymphoma.

Adolescent↗
PubMed2003

Standard and increased-dose BEACOPP chemotherapy compared with COPP-ABVD for advanced Hodgkin's disease.

BACKGROUND: Faced with unsatisfactory results of treatment for advanced Hodgkin's disease, we investigated three combinations of chemotherapy. METHODS: From 1993 to 1998, 1201 eligible patients 15 to 65 years of age who had newly diagnosed Hodgkin's disease in unfavorable stage IIB or IIIA or stage IIIB or IV were randomly assigned to receive eight cycles of cyclophosphamide, vincristine, procarbazine, and prednisone alternating with doxorubicin, bleomycin, vinblastine, and dacarbazine (COPP-ABVD); bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP); or increased-dose BEACOPP, each followed by local radiotherapy when indicated. Enrollment in the COPP-ABVD group was stopped in 1996 owing to inferior results. RESULTS: For the final analysis, 1195 of 1201 patients could be evaluated: 260 in the COPP-ABVD group, 469 in the BEACOPP group, and 466 in the increased-dose BEACOPP group; the median follow-up was 72, 54, and 51 months, respectively. The rate of freedom from treatment failure at five years was 69 percent in the COPP-ABVD group, 76 percent in the BEACOPP group, and 87 percent in the increased-dose BEACOPP group (P=0.04 for the comparison of the COPP-ABVD group with the BEACOPP group and P<0.001 for the comparison of the increased-dose BEACOPP group with the COPP-ABVD group and with the BEACOPP group), and the five-year rates of overall survival were 83 percent, 88 percent, and 91 percent, respectively (P=0.16 for the comparison of the COPP-ABVD group with the BEACOPP group, P=0.06 for the comparison of the BEACOPP group with the increased-dose BEACOPP group, and P=0.002 for the comparison of the COPP-ABVD group with the increased-dose BEACOPP group). Rates of early progression were significantly lower with increased-dose BEACOPP than with COPP-ABVD or standard BEACOPP. CONCLUSIONS: Increased-dose BEACOPP resulted in better tumor control and overall survival than did COPP-ABVD.

Aged↗
PubMed2002

Rapidly alternating COPP/ABV/IMEP is not superior to conventional alternating COPP/ABVD in combination with extended-field radiotherapy in intermediate-stage Hodgkin's lymphoma: final results of the German Hodgkin's Lymphoma Study Group Trial HD5.

PURPOSE: To investigate whether treatment results in intermediate-stage Hodgkin's lymphoma can be improved by rapid application of non-cross-resistant drugs, the 10-drug regimen cyclophosphamide, vincristine, procarbazine, and prednisone (COPP), doxorubicin, bleomycin, and vinblastine (ABV), and ifosfamide, methotrexate, etoposide, and prednisone (IMEP), repeated every 6 weeks, was compared with conventional alternating COPP/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) administered every 8 weeks. PATIENTS AND METHODS: From January 1988 to January 1993, 996 patients in stage I or II Hodgkin's lymphoma with at least one risk factor (massive mediastinal tumor, massive spleen involvement, extranodal disease, elevated ESR, or more than two lymph node areas involved) and all patients in stage IIIA Hodgkin's lymphoma were randomized to receive two cycles of COPP/ABVD or COPP/ABV/IMEP followed by extended-field radiotherapy. RESULTS: Both regimens produced similar rates for treatment responses (complete remission, 93% v 94%), freedom from treatment failure (80% v 79%), and overall survival (88% for both regimens) at a median follow-up time of 7 years. Most serious toxicities during chemotherapy were similar in both regimens. However, World Health Organization grade 3 and 4 leukocytopenia occurred significantly more frequently in the COPP/ABV/IMEP arm (53% v 44% of patients; P =.010). There were no differences in the number of serious infections and toxic deaths during therapy. The number of second malignancies was also the same in both arms (22 each). CONCLUSION: Alternating COPP/ABVD and rapid alternating COPP/ABV/IMEP in combination with extended-field radiotherapy are equally effective in intermediate-stage Hodgkin's lymphoma and produce excellent long-term treatment results.

Adolescent↗
PubMed2002

A novel dynamic model of hematopoietic stem cell organization based on the concept of within-tissue plasticity.

OBJECTIVE: At present, no dynamic quantitative models of stem cell organization are available that fulfill all criteria of the prevalent functional definition of hematopoietic stem cells and, at the same time, provide a consistent explanation of cell kinetic and functional stem cell heterogeneity, reversibility of cellular properties, self-organized regeneration after damage, fluctuating activity and competition of stem cell clones, and microenvironment dependency of stem cell quality. To solve this problem, we propose a new, comprehensive model concept. MATERIALS AND METHODS: A single cell-based stochastic model is described. It makes the novel concept of within-tissue plasticity operational. Within a range of potential options, individual cells may reversibly change their actual set of properties depending on the influence of the local growth environment. Stochastic switching between the growth environments introduces fluctuations that eventually generate heterogeneity. Extensive model simulations are compared with experimental data. RESULTS: Although stemness is not an explicit cellular model property, the system behavior is consistent with the functional definition of stem cells and explains a large set of experimental observations on stem cell function in vivo and in vitro on the level of cell populations and individual cells. Classic results such as the colony-forming unit spleen assay, as well as recent experimental observations on stem cell kinetics, individual clone tracking, and fluctuating clonal contribution, are discussed. CONCLUSIONS: This concept introduces a fundamentally new perspective on stem cell organization treating stemness not as an explicit cellular property but as the result of a dynamic process of self-organization. The model needs to be extended to incorporate lineage specification and tissue plasticity.

Animals↗
PubMed2002

Tissue stem cells: definition, plasticity, heterogeneity, self-organization and models--a conceptual approach.

The classical definition of adult tissue stem cells (TSC) is fundamentally based on a functional perspective. A TSC is an undifferentiated cell, capable of proliferation, self-renewal, production of a large number of differentiated functional progeny, regenerating tissue after injury and a flexibility in the use of these options. Here, we discuss the necessity for amending this definition in the light of recent insight into stem cell biology regarding stem cell heterogeneity, lineage plasticity, clonal fluctuation and cell-environment interactions. We conclude that the definition needs amendments. A decade ago the flexibility criterion has attracted little attention but recent findings have indicated its importance. Flexibility and reversibility of tissue and lineage specification (tissue plasticity) and of properties within a tissue (within-tissue plasticity) have major implications with regard to concepts of stem cell function. We advocate to give up the view of TSC as being entities with a preprogrammed development and to replace it by a concept that makes the capabilities for flexible and regulated tissue self-organization based on cell-cell and cell-environment interactions the new paradigm. This concept would permit to incorporate the context-dependent lineage plasticity, within-lineage plasticity and generation of stem cell heterogeneity as a result of a dynamically regulated process. Such concepts need a rigorous examination by formal modeling including simulation studies. We provide some general ideas on how to proceed with such theories and illustrate this with worked models for tissue stem cells of the hematopoietic system and the intestinal epithelium.

Animals↗