Search PubMed⌕ Search

Biomedical subjects

A Hagenbeek

Publications and source records attributed to A Hagenbeek.

At least 37 records · Page 2Linked to original sources
PubMed2000

Increased risk of breast cancer following irradiation for Hodgkin's disease is not a result of ATM germline mutations.

PURPOSE: Long-term survivors of Hodgkin's disease who received mantle-field irradiation at a young age have a strongly increased risk of developing breast cancer. The purpose of this study was to investigate whether this increased risk was substantially greater among women heterozygous for a germline mutation in the ataxia-telangiectasia gene (ATM). MATERIALS AND METHODS: Thirty-two patients were selected who had developed breast cancer at least 10 years following irradiation for Hodgkin's disease before the age of 45 years. In these patients, the complete open reading frame of the ATM gene was analysed for the presence of germline mutations using the protein truncation test and two mutation-specific tests, followed by genomic sequencing. RESULTS: No A-T disease causing germline mutations were found in these selected Hodgkin patients. However, several alternative splicing events were detected which might influence protein expression levels. CONCLUSIONS: The data suggest that truncating mutations in the ATM gene are not a major component underlying the increased risk of breast cancer following Hodgkin's disease.

Adult↗
PubMed2000

Long-term risk of second malignancy in survivors of Hodgkin's disease treated during adolescence or young adulthood.

PURPOSE: To quantify the long-term risk of second primary cancers (SCs) in patients diagnosed with Hodgkin's disease (HD) during adolescence or young adulthood. PATIENTS AND METHODS: The risk of SCs was assessed in 1,253 patients diagnosed with HD before the age of 40 years and treated in two Dutch cancer centers between 1966 and 1986. The median follow-up duration was 14.1 years. RESULTS: In all, 137 patients developed SCs, compared with 19.4 cases expected on the basis of incidence rates in the general population (relative risk [RR] = 7.0; 95% confidence interval, 5.9 to 8.3). The 25-year actuarial risk of SC overall was 27.7%. The RR of solid tumors increased greatly with younger age at the first treatment of HD, not only for breast cancer but also for all other solid tumors, with RRs of 4.9, 6.9, and 12.7 for patients first treated at ages 31 to 39 years, 21 to 30 years, and </= 20 years, respectively. Among patients first treated at the age of 20 years or younger, the RR of developing a solid tumor before the age of 40 years was significantly greater than the RR of solid tumor development at ages 40 to 49 years (RR = 27.9 v RR = 4.2; P =.0001). Patients who received salvage chemotherapy had significantly greater risk of solid cancers other than breast cancer than did patients whose treatment was restricted to initial radiotherapy or initial combined-modality treatment (RR = 9.4 and 4.7, respectively; P =. 004). CONCLUSION: After more than 20 years of follow-up, the risk of solid tumors is still much greater in survivors of HD than in the population at large. Reassuringly, the greatly increased risk of solid tumors in patients who were young (</= 20 years of age) at the first treatment seems to decrease as these patients grow older. Our data suggest that chemotherapy may increase the risk of solid tumors from radiotherapy.

Adolescent↗
PubMed1999

[Dose reduction is not recommended for elderly patients undergoing chemotherapy for non-Hodgkin lymphoma].

The treatment of choice for patients over 60 years of age with aggressive non-Hodgkin's lymphoma (NHL) consists of chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP). Because of poor tolerance, dose reductions and delays occur frequently. However, because of the relatively low dose intensity significantly more patients die of refractory or relapse lymphoma. If it is intended to cure these patients, unmitigated CHOP chemotherapy should be applied. When needed additional supportive care can be provided.

Aged↗
PubMed1999

Reverse chromosome painting for the identification of marker chromosomes and complex translocations in leukemia.

BACKGROUND: Chromosome banding techniques and in situ hybridization reveal the majority of chromosomal aberrations. However, difficulties remain in cases of highly contracted chromosomes, poor quality of the metaphases or the presence of markers with the involvement of several chromosomes. Here, it is demonstrated that reverse painting can be applied successfully starting with bone marrow cells from primary acute myelocytic leukemias (AML). METHODS: This was accomplished by culturing the leukemic cells with a cocktail of various growth factors, which yielded sufficient numbers of cells in cycle to harvest chromosomes for sorting. Aberrant chromosomes were flow-sorted and amplified by degenerate oligonucleotide-primed PCR. The resulting products were labeled by nick-translation and hybridized on normal metaphase spreads. RESULTS: Two patients with marker chromosomes in their leukemia cells were analyzed in detail. The hybridization pattern displayed the composition of the aberrant sorted chromosome. Results were compared with conventional cytogenetic analyses that were performed on material obtained from the same aspirate. The reverse-painting technique enabled identification of aberrations that were not detected by conventional cytogenetic analysis. CONCLUSIONS: Primary AML cells can be cultured in vitro, using optimal culture conditions, facilitating the production of high quality flow karyotypes, suitable for sorting of marker chromosomes to produce DOP-PCR derived chromosome painting probes for reverse painting. Valuable additional cytogenetic information can thus be obtained about complex chromosomal rearrangements or structural aberrations that could not be completely resolved by conventional cytogenetic analysis.

Bone Marrow↗
PubMed1999

Amifostine (WR2721) for dose escalation in marrow-ablative treatment of leukaemia.

The in vivo effect of the radiochemoprotectant Amifostine on the therapeutic efficacy of marrow ablative treatment with cyclophosphamide (CP) and total body irradiation (TBI) followed by bone marrow transplantation (BMT) was studied in normal rats as well as in the Brown Norway rat acute myelocytic leukaemia (BNML) model. In normal rats, when the dose of TBI was escalated and the CP dose was kept constant, pretreatment with Amifostine yielded a positive dose modification factor of 1.26. No significant improvement was found after Amifostine pretreatment when the TBI dose was kept constant and CP dose escalated. When leukaemic rats received CP as the only antileukaemia treatment, Amifostine pretreatment did not lead to a reduction in the antileukaemic efficacy of CP, although protection against treatment-related mortality was observed. In the CP only groups, 9 out of 40 animals died of treatment-related toxicity, compared with none of the 40 animals in the Amifostine pretreatment groups. When applying the maximum tolerated treatment of CP and TBI in various combinations to leukaemic rats, 25 out of 36 rats died from treatment-related toxicity, whilst pretreatment with Amifostine reduced this to 11 out of 36, (P = 0.002). Of those animals which survived the CP + TBI conditioning treatment, 10 out of 25 in the Amifostine pretreatment group were cured, versus 8/11 in the CP + TBI only control group (P = 0.146). In conclusion, incorporation of Amifostine as a radiochemoprotectant in a marrow-ablative conditioning regimen allows the use of escalated doses of chemoradiotherapy without reducing the antileukaemic efficacy.

Amifostine↗
PubMed1999

Peripheral blood stem cell transplantation as an alternative to autologous marrow transplantation in the treatment of acute myeloid leukemia?

The clinical use of autologous marrow transplantation in acute myeloid leukemia (AML) has been hampered by the inability to collect adequate numbers of cells after remission induction chemotherapy and the notably delayed hematopoietic regeneration following autograft reinfusion. Here we present a study in which the feasibility of mobilizing stem cells was investigated in newly diagnosed AML. Among 96 AML patients, 76 patients (79%) entered complete remission. Mobilization was undertaken with low dose and high dose schedules of G-CSF in 63 patients, and 54 patients (87%) were leukapheresed. A median of 2.0 x 10(6) CD34+ cells/kg (range 0.1-72.0) was obtained in a median of three leukaphereses following a low dose G-CSF schedule (150 microg/m2) during an average of 20 days. Higher dose regimens of G-CSF (450 microg/m2 and 600 microg/m2) given during an average of 11 days resulted in 28 patients in a yield of 3.6 x 10(6) CD34+ cells/kg (range 0-60.3) also obtained following three leukaphereses. The low dose and high dose schedules of G-CSF permitted the collection of 2 x 10(6) CD34-positive cells in 46% and 79% of cases respectively (P = 0.01). Twenty-eight patients were transplanted with a peripheral blood stem cell (PBSC) graft and hemopoietic repopulation was compared with the results of a previous study with autologous bone marrow. Recovery of granulocytes (>0.5 x 10(9)/l, 17 vs 37 days) and platelets (>20 x 10(9)/l; 26 vs 96 days) was significantly faster after peripheral stem cell transplantation compared to autologous bone marrow transplantation. These results demonstrate the feasibility of PBSCT in the majority of cases with AML and the potential advantage of this approach with respect to hemopoietic recovery.

Acute Disease↗
PubMed1999

Ganciclovir-mediated in vivo elimination of myeloid leukemic cells expressing the HSVtk gene induces HSVtk loss variants.

The in vivo elimination of suicide gene-expressing tumor cells with prodrug treatment can induce protective immunity against wild-type tumors. In this study, we determined the efficacy and safety of the in vivo elimination of HSVtk expressing cells with ganciclovir treatment of a bystander cell killing-insensitive leukemic cell line. The retroviral construct pLTk+NeoDeltaMo, containing the HSVtk gene and the NeoR gene in a bicistronic unit, was introduced into rat leukemic LT12 cells. LT12/Tk+N cells showed a 1000- to 10 000-fold increased sensitivity to ganciclovir in vitro. In vitro mixing experiments demonstrated that LT12 cells were not susceptible to bystander cell lysis by LT12/Tk+N-2 cells exposed to ganciclovir. Rats injected s.c. with cloned LT12/Tk+N-2 cells developed tumors reaching a diameter of 3-4 cm after 40 days. Rats treated with gan- ciclovir twice daily for 5 consecutive days starting at day 7 did not develop s.c. tumors. Large established s.c. LT12/Tk+N-2 tumors completely regressed after ganciclovir treatment. However, recurrences of s.c. tumors were observed that were no longer sensitive to ganciclovir treatment. In vitro analysis of aspirates from the recurrent tumors demonstrated loss of HSVtk expression. In vitro culture of LT12/Tk+N-2 cells in soft agar in the presence of ganciclovir indicated that the frequency with which HSVtk-loss variants occurred is approximately one per 104 cells. The in vivo occurrence of HSVtk-loss variants escaping ganciclovir-induced elimination may have important implications for vaccination protocols using HSVtk gene expressing tumor cells that are not susceptible to bystander cell killing.

Animals↗
PubMed1999

Report of an international workshop to standardize response criteria for non-Hodgkin's lymphomas. NCI Sponsored International Working Group.

Standardized guidelines for response assessment are needed to ensure comparability among clinical trials in non-Hodgkin's lymphomas (NHL). To achieve this, two meetings were convened among United States and international lymphoma experts representing medical hematology/oncology, radiology, radiation oncology, and pathology to review currently used response definitions and to develop a uniform set of criteria for assessing response in clinical trials. The criteria that were developed include anatomic definitions of response, with normal lymph node size after treatment of 1.5 cm in the longest transverse diameter by computer-assisted tomography scan. A designation of complete response/unconfirmed was adopted to include patients with a greater than 75% reduction in tumor size after therapy but with a residual mass, to include patients-especially those with large-cell NHL-who may not have residual disease. Single-photon emission computed tomography gallium scans are encouraged as a valuable adjunct to assessment of patients with large-cell NHL, but such scans require appropriate expertise. Flow cytometric, cytogenetic, and molecular studies are not currently included in response definitions. Response rates may be the most important objective in phase II trials where the activity of a new agent is important and may provide support for approval by regulatory agencies. However, the goals of most phase III trials are to identify therapies that will prolong the progression-free survival, if not the overall survival, of the treated patients. We hope that these guidelines will serve to improve communication among investigators and comparability among clinical trials until clinically relevant laboratory and imaging studies are identified and become more widely available.

Clinical Trials as Topic↗
PubMed1998

Second gene expression in bicistronic constructs using short synthetic intercistrons and viral IRES sequences.

In this study, we describe the efficiency of second gene translation in bicistronic constructs containing either a short (36bp) synthetic intercistron or known internal ribosomal entry sites (IRES). Experiments were performed using two different gene combinations: Herpes simplex virus-thymidine kinase (HSV-TK) and neomycine (NEO) or human glucocerebrosidase (hGC) and a methotrexate (MTX) resistant mutant dihydrofolate reductase (DHFR). We demonstrate that upon transfection, second gene translation is efficient using either an IRES or a 36-bp intercistron. Infection with retrovirus carrying the TK and NEO genes linked via a 36-bp intercistron resulted in both G418R (NEO expression) and gancyclovir (GCV) sensitivity (TK expression), indicating that both genes were expressed and thus that the genomic DNA and RNA of this bicistronic construct were intact. Likewise, retrovirus carrying the hGC and mutant DHFR gene separated by a short intercistron was harvested from MTXR murine PsiCRE cells. However, infection of PA317 cells with this virus supernatant did not result in the presence of hGC enzyme activity in these murine cells. Proviral DNA and RNA analyses indicated that the hGC coding region was lost from the original construct in the infected PA317 cells. In contrast, retrovirus carrying the hGC and DHFR cDNAs was linked via an IRES functioned as expected. Based on these results, we conclude that the efficiency of second gene translation using short synthetic intercistrons might prove useful in bicistronic constructs, depending on the gene combination used.

Animals↗
PubMed1998

The International Prognostic Index correlates to survival in patients with aggressive lymphoma in relapse: analysis of the PARMA trial. Parma Group.

The objectives of the present study were to investigate the prognostic value of the International Prognostic Index (IPI) at relapse in the 215 patients with intermediate- or high-grade non-Hodgkin's lymphoma (NHL) included in the PARMA trial. The IPI at relapse was available in 204 (95%) of these patients. Response rates to 2 courses of DHAP were 77%, 54%, 55%, and 42% in patients with an IPI of 0, 1, 2 and 3, respectively (P <.02), whereas complete response (CR) rates were 33%, 29%, 20%, and 0% in the same groups of patients (P <.03). With a median follow-up period of 79 months, overall survival (OS) at 5 years was 46%, 25%, 25%, and 11% in these four groups (P <.001). One hundred nine patients responding to 2 courses of DHAP were randomized to receive either BEAC (carmustine, etoposide, cytarabine, cyclophosphamide and mesna) followed by autologous bone marrow transplantation (ABMT) or 4 additional courses of DHAP: IPI at relapse was found highly correlated to OS in patients treated in the DHAP arm (5-year OS: 48%, 21%, 33%, and 0% for IPI 0, 1, 2, and 3, respectively; P =.006), but not in the BEAC arm (5-year OS: 51%, 47%, 50%, and 50% for IPI 0, 1, 2, and 3, respectively; P =.90). OS was significantly superior in the BEAC arm as compared with the DHAP arm in patients with an IPI >0 (P <.05), but not in patients with an IPI of 0. In conclusion, these results show that IPI correlates to response and overall survival in patients with aggressive NHL in relapse and enables us to identify patients with a significantly different outcome among those treated with conventional chemotherapy alone.

Adolescent↗
PubMed1998

For which patients with aggressive non-Hodgkin's lymphoma is prophylaxis for central nervous system disease mandatory? Dutch HOVON Group.

PURPOSE: Data of a multicenter study in non-Hodgkin's lymphoma (NHL) by the Dutch Hovon Group were reanalyzed to assess the risk of relapse in the central nervous system (CNS) related to the international risk index for NHL. In addition we assessed the risk for CNS disease in relation to the presence of bone marrow localisation at presentation. DESIGN: We focused our analysis on those patients reaching a complete remission (CR). Two hundred eighty-six patients (histological subtypes D-H Working Formulation) and with stages II-IV were analyzed. One hundred ninety-three (67%) patients reached a CR. RESULTS: Relapse occurred in 78 patients of whom 10 patients with concomitant or isolated CNS disease. According to the international risk index the following observations were made: low risk (n = 38) nine out of 34 CR relapsed, none had CNS involvement; low-intermediate risk (n = 115) 27 out of 83 CR relapsed, three had CNS involvement; high-intermediate risk (n = 110) 37 out of 68 CR relapsed, six had CNS involvement; high risk (n = 22) four out of seven CR relapsed, one had CNS involvement. Two out of 10 developed isolated CNS disease and eight out of 10 patients developed CNS disease with systemic relapse. CONCLUSION: Our data show that the number of CNS relapses after CR is relatively low (10 out of 193 = 5%), with an increasing incidence in the high-risk groups according to the international risk index. The occurrence of CNS relapse seems to be related to the risk of systemic relapse after CR. No subgroup could be discriminated in which prophylactic treatment would be of substantial benefit.

Adolescent↗
PubMed1998

Influence of ultraviolet-B irradiation on engraftment, graft-versus-host disease and graft-versus-leukemia effect in a rat model for allogeneic bone marrow transplantation.

Ultraviolet-B (UVB) irradiation is known to inhibit lymphocyte activity and consequently to reduce the incidence of graft-versus-host disease (GVHD) in experimental models for allogeneic bone marrow transplantation (BMT). GVHD is frequently associated with morbidity and mortality, but also with the beneficial graft-versus-leukemia (GVL) effect, demonstrated by a reduction in the incidence of leukemia relapse. In this study, we investigated whether UVB treatment of allogeneic T cells could prevent GVHD while sparing the beneficial GVL effect following allogeneic BMT in the Brown Norway myelocytic leukemia (BNML) rat model analogous to human acute myelocytic leukemia (AML). The dose of UVB required to abolish lethal GVHD in the rat allogeneic BMT model (WAG/Rij donors into BN recipients) was 4000 J/m2. However, this UVB dose simultaneously abrogated all GVL activity mediated by the T cells in the graft, while the radio-protective capacity of rat BM cells was strongly reduced. The number of allogeneic BM cells required to protect lethally irradiated BN rats was increased 50 to 100-fold. It is concluded that UVB acts as a non-selective form of T cell inactivation, and that UVB pretreatment of an allogeneic marrow graft is unlikely to be useful clinically as a preventive measure for GVHD, since other means of reduction of the number of functional T cells are less damaging to bone marrow stem cells.

Animals↗
PubMed1998

In vivo targeting of leukemic cells using diphtheria toxin fused to murine GM-CSF.

We have previously demonstrated that diphtheria toxin (DT) fused to human GM-CSF effectively eliminates human long-term leukemia initiating cells in SCID mice. However, because huGM-CSF does not react with the murine GM-CSF receptor possible side-effects to nonleukemic tissues could not be analyzed in the AML/SCID model. To overcome this problem, we used murine GM-CSF fused to DT and studied the therapeutic index in the rat leukemia model BNML/LT12. In DT-mGM-CSF dose escalation experiments, severe dose-dependent toxicity to organs such as liver, kidney and lung was observed. Therefore, the antileukemic effects were evaluated with the lower doses. Daily intraperitoneal bolus injections of 75 microg/kg/day for 7 days induced a 3 log leukemic cell kill. The dose of 75 microg/kg/day had no effect on the hemopoietic progenitor cell subsets. These in vivo studies show that the DT-GM-CSF fusion protein can be used for specifically targeting leukemic cells and thus has potential as a therapeutic agent in the treatment of AML.

Animals↗
PubMed1998

GM-CSF receptor targeted treatment of primary AML in SCID mice using Diphtheria toxin fused to huGM-CSF.

The severe combined immunodeficient (SCID) mouse model may be used to evaluate new approaches for the treatment of acute myeloid leukemia (AML). We have previously demonstrated the killing of SCID mouse leukemia initiating cells by in vitro incubation with human GM-CSF fused to Diphtheria toxin (DT-huGM-CSF). In this report, we show that in vivo treatment with DT-huGM-CSF eliminates AML growth in SCID mice. Seven cases of AML were studied. SCID mice were treated intraperitoneally with the maximally tolerated dose of 75 microg/kg/day for 7 days. Antileukemic efficacy was determined at days 40 and 80 after transplantation, by enumerating the percentages of human cells in SCID bone marrow using flow cytometry and short tandem repeat polymerase chain reaction (STR-PCR) analysis. Four out of seven AML cases were sensitive to in vivo treatment with DT-huGM-CSF at both evaluation time points. In three of these cases, elimination of human cells was demonstrated by flow cytometry and STR-PCR. One AML case showed moderate sensitivity for DT-huGM-CSF, and growth of the two remaining AML cases was not influenced by DT-huGM-CSF. Sensitivity was correlated with GM-CSFR expression. Our data show that DT-huGM-CSF can be used in vivo to reduce growth of AML and warrant further development of DT-huGM-CSF for the treatment of human AML.

Animals↗
PubMed1998

Maintenance of remission with human recombinant interferon alfa-2a in patients with stages III and IV low-grade malignant non-Hodgkin's lymphoma. European Organization for Research and Treatment of Cancer Lymphoma Cooperative Group.

PURPOSE: Interferon alfa has shown significant activity in patients with low-grade malignant non-Hodgkin's lymphoma (NHL). In 1985, we initiated a prospective randomized study in which the potential benefit of interferon alfa given as maintenance treatment was investigated after tumor load reduction was achieved with chemoradiotherapy in patients with advanced low-grade malignant non-Hodgkin's lymphoma. PATIENTS AND METHODS: The study involved 347 patients with stage III or IV disease, 315 satisfying the eligibility criteria. All were treated with a regimen of cyclophosphamide, vincristine, and prednisone (CVP) given every 3 weeks for eight cycles. Thereafter, patients were eligible for iceberg irradiation. Finally, all patients were completely restaged, and responding and stable-disease patients were then randomized, 122 to interferon alfa-2a maintenance, 3 million U three times weekly for 1 year; and 120 to no further treatment. RESULTS: Seventy-nine percent of the patients response to CVP, ie, 45% complete remissions (CR) and 34% partial remissions (PR). In the group of randomized patients, the response rate after CVP plus or minus radiotherapy was 90%. As compared with control patients, patients in the interferon (IFN) maintenance group had a tendency toward a prolonged time to progression (TTP) (median, 132 v 87 weeks; P = .054, adjusted for response to CVP). However, overall survival was similar in both groups. Interferon was well tolerated. The median dose of IFN actually received corresponded to 90% of the planned cumulative dose. The treatment had to be stopped because of toxicity in 16 patients (15% of the patients in whom IFN was started). CONCLUSION: Interferon maintenance treatment in the phase of minimal residual disease of patients with advanced low-grade malignant NHL increased TTP at the borderline of statistical significance, without remarkable toxicity. However, overall survival was not influenced.

Adult↗
PubMed1998

Time to relapse has prognostic value in patients with aggressive lymphoma enrolled onto the Parma trial.

PURPOSE: The purpose of this study was to investigate the prognostic value of time to relapse in 188 adult patients with intermediate- or high-grade non-Hodgkin's lymphoma (NHL) included on the Parma trial at the time of their first relapse. PATIENTS AND METHODS: The median follow-up of these patients is 102 months after registration onto the Parma study. Time to relapse was calculated from initial diagnosis, and a cutoff of 12 months was used to separate 77 patients defined as early relapse from 111 patients defined as late relapse. RESULTS: Patients with early and late relapses had significantly different overall response rates to salvage therapy with two courses of dexamethasone, high-dose cytarabine, and cisplatin (DHAP; 40% v 69%; P=.00007) and different 8-year survival rates (13% v 29%; P=.00001). Features at relapse with a negative prognostic value in univariate analysis were higher than normal lactic dehydrogenase (LDH) levels, tumor size greater than 5 cm, Ann Arbor stages III to IV, and Karnofsky score less than 80%. Therefore, multivariate analyses were performed. Time to relapse (P=.001) and LDH levels at relapse (P=.003) had independent prognostic value, whereas tumor size did not reach statistical significance in the logistic model that predicted overall response after two courses of DHAP. The study of prognostic factors for overall survival (OS) and progression-free survival (PFS) confirmed the prognostic value of time to relapse (P < .0001 for OS and P=.005 for PFS) independent of response or treatment after two courses of DHAP. CONCLUSION: Time to relapse may be used to stratify patients at time of first relapse of intermediate to high-grade non-Hodgkin's lymphoma.

Adult↗