Immune cells regulate VEGF signalling via release of VEGF and antagonistic soluble VEGF receptor-1.

Vascular endothelial growth factor (VEGF) is an important regulator of physiological and pathological angiogenesis. Besides malignant and stromal cells, local immune cells shape VEGF signalling in the tumour microenvironment. Aminobisphosphonates such as zoledronic acid (Zol) are drugs known to inhibit osteoclast activity and bone resorption, but also have immunomodulatory and anti-tumour effects. These properties have been linked previously to the down-regulation of VEGF and interference with tumour neo-angiogenesis. It was therefore surprising to find that treatment with Zol in combination with low-dose interleukin (IL)-2 increased serum VEGF levels in cancer patients. In this study we aimed to characterize the effect of Zol and IL-2 on VEGF signalling of blood-derived immune cells in vitro. Upon stimulation with IL-2, T cells and natural killer (NK) cells increase production of VEGF consecutively to the release of proinflammatory interferon (IFN)-γ, and Zol accelerates this response specifically in γδ T cells. VEGF can, in turn, be antagonized by soluble VEGF receptor (sVEGFR)-1, which is released depending on stimulatory conditions and the presence of monocytes. Additionally, malignant cells represented by leukaemia and lymphoma cell lines produce VEGF and some release sVEGFR-1 simultaneously. Our findings indicate a mechanism by which the VEGF and the sVEGFR-1 production by immune cells regulates local VEGF signalling. Therefore, immunotherapeutic interventions may enable both pro- as well as anti-tumour effects via immune cell-mediated alterations of VEGF homeostasis.

First-line therapy of peripheral T-cell lymphoma: extension and long-term follow-up of a study investigating the role of autologous stem cell transplantation.

Current guidelines recommend consolidation with autologous stem cell transplantation (autoSCT) after induction chemotherapy for most patients with peripheral T-cell lymphoma (PTCL). This assumption is based on five prospective phase II studies, three of which included <50 patients with limited follow-up. Here we present the final analysis of the prospective German study. The treatment regimen consisted of four to six cycles of CHOP chemotherapy followed by mobilizing therapy and stem cell collection. Patients in complete remission (CR) or partial remission (PR) underwent myeloablative chemo(radio)therapy and autoSCT. From January 2001 to July 2010, 111 patients were enrolled in the study. The main subgroups were PTCL not specified (n=42) and angioimmunoblastic T-cell lymphoma (n=37). Seventy-five (68%) of the 111 patients received transplantation. The main reason for not receiving autoSCT was progressive disease. In an intent-to-treat analysis, the complete response rate after myeloablative therapy was 59%. The estimated 5-year overall survival, disease-free survival and progression-free survival rates were 44%, 54% and 39%, respectively. The results of this study confirm that upfront autoSCT can result in long-term remissions in patients with all major subtypes of PTCL and therefore should be part of first-line therapy whenever possible.

Prognostic impact of meningeal dissemination in primary CNS lymphoma (PCNSL): experience from the G-PCNSL-SG1 trial.

BACKGROUND: We evaluated the frequency and prognostic impact of meningeal dissemination (MD) in immunocompetent adult patients with primary central nervous system lymphoma treated in a randomized phase III trial. PATIENTS AND METHODS: MD was evaluated at study entry and defined by lymphoma proof in the meningeal compartment detected by at least one of the following methods: cerebrospinal fluid (CSF) cytomorphology, detection of clonal B cells by IgH PCR in CSF or contrast enhancement of the leptomeninges on magnetic resonance imaging (MRI). RESULTS: Data on MD were available in 415 patients, of those, MD was detected in 65 (15.7%): in 44/361 (12.2%) by CSF cytomorphology, in 16/152 (10.5%) by PCR and in 17/415 (4.1%) by MRI. Major patients' characteristics and therapy did not significantly differ between patients with MD (MD+) versus those without MD (MD-). There was a significant correlation of MD with CSF pleocytosis (>5/µl; P < 0.0001), but no correlation with CSF protein elevation (>45 mg/dl). Median progression-free survival was 6.7 months [95% confidence interval (CI) 0-14.5] in MD+ and 8.3 months (5.7-10.8) in MD- patients (P = 0.95); median overall survival was 21.5 months (95% CI 16.8-26.1) and 24.9 months (17.5-32.3), respectively (P = 0.98). CONCLUSION: MD was detected infrequently and had no impact on outcome in this trial.

Adult-onset Still's disease and chronic recurrent multifocal osteomyelitis: a hitherto undescribed manifestation of autoinflammation.

Still's disease and chronic recurrent multifocal osteomyelitis (CRMO) are febrile rheumatic diseases of unknown etiology, which predominantly affect children but can also have their initial manifestation in adults. Both can present as intermittent, relapsing episodes and are considered potential candidates within the expanding spectrum of autoinflammatory disorders, although no genetic abnormalities have been described for either of them. Here, we describe a man with an initial manifestation of abacterial multifocal osteitis at the age of 41. During a relapsing-remitting course of his illness, he increasingly developed symptoms of adult-onset Still's disease (AOSD), and the diagnosis was established according to the Yamaguchi criteria. When treated with anakinra, not only the acute symptoms disappeared promptly, but also the osteitis went into complete remission. This is to our knowledge the first description of a simultaneous occurrence of these two manifestations of autoinflammation in adulthood.

Clinical-scale single-step CD4(+) and CD8(+) cell depletion for donor innate lymphocyte infusion (DILI).

The ability to selectively deplete or enrich cells of specific phenotype by immunomagnetic selection to reduce the risk of GVHD holds significant promise for application in adoptive immunotherapy. Current clinical-scale approaches for T-cell depletion (e.g., CD34(+) selection, CD3(+) depletion), usually deplete gammadelta T cells, which may be advantageous in mediating graft-versus-tumor (GVT) effects and augmenting the innate immune response against infections. Here, we present a new method for depletion of T cells with potential GVHD reactivity by using a single-step immunomagnetic protocol, which efficiently depletes CD4(+) and CD8(+) alphabeta T cells under good manufacturing practice (GMP) conditions. Depletion from unstimulated leukapheresis products (n=6) containing up to 2.0 x 10(10) cells showed high efficiency (mean log depletion of CD4(+) cells: 4.12, CD8(+) cells: 3.77). In addition, immunomagnetic CD4/CD8 depletion resulted in passive enrichment of innate lymphocytes (mean recovery of natural killer (NK) cells: 38%, gammadelta T cells: 50%). We demonstrated that gammadelta/NK cells preserved their proliferative and cytotoxic capacity and conclude that simultaneous large-scale depletion of CD4(+)/CD8(+) T cells is feasible and can be performed under GMP conditions with high-depletion efficacy for alphabeta T cells and recovery of functionally intact innate effector lymphocytes for potential use in adoptive immunotherapy studies.

Prospective trial on topotecan salvage therapy in primary CNS lymphoma.

BACKGROUND: Standard salvage therapy has not been established for recurrent primary central nervous system lymphoma (PCNSL). We report the final results of a prospective study on topotecan chemotherapy in relapsed or refractory PCNSL. PATIENTS AND METHODS: The study included 27 patients with a median age of 51 years and an ECOG performance status of 2. Fourteen patients were refractory to the last therapy, and 13 relapsed after a median period of 6.0 months. Pretreatment with up to four regimens included chemotherapy in 26 patients and whole brain irradiation in 14. A 30-min daily topotecan infusion of 1.5 mg/m(2) for 5 days was repeated every 3 weeks. RESULTS: The response rate was 33% with five complete (CR) and four partial remissions (PR). The median follow-up was 37.7 months. All complete responders had sustained remissions lasting for 9 to 28 months. The median event-free survival (EFS) was 2.0 months (9.1 months in responders), the overall survival (OAS) was 8.4 months. CTC grade 3-4 leukopenia occurred in 26% and thrombocytopenia in 11% of the patients. Eight of 12 patients alive without cerebral lymphoma > or = six months after topotecan exhibited deficits attributable to late neurotoxicity. CONCLUSION: Topotecan as monotherapy is active in relapsed and refractory PCNSL with tolerable toxicity.

A therapeutic platelet transfusion strategy is safe and feasible in patients after autologous peripheral blood stem cell transplantation.

Prophylactic platelet transfusions are considered as standard in most hematology centers, but there is a long-standing controversy as to whether standard prophylactic platelet transfusions are necessary or whether this strategy could be replaced by a therapeutic transfusion strategy. In 106 consecutive cases of patients receiving 140 autologous peripheral blood stem cell transplantations, we used a therapeutic platelet transfusion protocol when patients were in a clinically stable condition. Platelet transfusions were only used when relevant bleeding occurred (more than petechial). Median duration of thrombocytopenia <20 x 10(9)/l and <10 x 10(9)/l was 6 and 3 days, which resulted in a total of 989 and 508 days, respectively. In only 26 out of 140 transplants (19%), we observed clinically relevant bleeding of minor or moderate severity. No severe or life-threatening bleeding was registered. The median and mean number of single donor platelet transfusions was one per transplant (range 0-18). One-third of all transplants, and 47% after high-dose melphalan could be performed without any platelet transfusion. Compared with a historical control group, we could reduce the number of platelet transfusions by one half. This therapeutic platelet transfusion strategy can be performed safely resulting in a considerable reduction in prophylactic platelet transfusions.

Busulfan, cyclophosphamide, and etoposide as high-dose conditioning regimen in patients with malignant lymphoma.

We investigated the efficacy and toxicity of the combination of busulfan, cyclophosphamide, and etoposide (Bu/Cy/VP-16) as a preparative regimen prior to autologous hematopoietic stem cell transplantation (ASCT) in patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL). Fifty-three patients with recurrent ( n=30), refractory ( n=20), or high-risk ( n=3) lymphoma were enrolled. The 10 patients with HD and 43 with NHL (median age: 46 years, range: 18-64) received busulfan (16 mg/kg), cyclophosphamide (120 mg/kg), and etoposide (30 or 45 mg/kg) followed by ASCT. A total of 50 patients (94%) were consolidated in complete ( n=25) or partial ( n=25) remission, whereas 3 patients had chemoresistant disease before Bu/Cy/VP-16. Thirty-five patients (66%) had received prior radiotherapy (RT) excluding total body irradiation (TBI) as part of the conditioning regimen. The main nonhematological toxicities (grade II-IV according to the Bearman score) in 52 evaluable patients were mucositis (79%) and hepatic toxicity (15%). Severe veno-occlusive disease (VOD) occurred in three patients (5.8%) including one treatment-related death caused by VOD. Overall, treatment-related mortality was 3.8%. After a median follow-up for surviving patients of 21 months (range: 6-118), 20 patients (38%) are in continuous complete remission, 8 patients (15%) are alive in relapse, and 25 patients (47%) died. Probabilities of relapse, event-free survival, and overall survival at 3 years were 63% [95% confidence interval (CI): 48-79%], 31% (95% CI: 17-46%), and 43% (95% CI: 27-59%), respectively. In conclusion, Bu/Cy/VP-16 is an effective and well-tolerated conditioning regimen in patients with HD and NHL. Both toxicity and outcome were not significantly different in patients treated with 30 mg/kg and 45 mg/kg etoposide, respectively. The observed long-term results are even comparable to those published for other established high-dose protocols, including TBI-based regimens. However, further investigations are necessary to evaluate the value of Bu/Cy/VP-16 as a high-dose protocol for malignant lymphoma, especially in patients who have already received extensive RT.

Salvage chemotherapy with mitoxantrone, fludarabine, cytarabine, and cisplatin (MIFAP) in relapsing and refractory lymphoma.

PURPOSE: The aim of the study was to evaluate the feasibility and efficacy of the combination of mitoxantrone, fludarabine, cytarabine, and cisplatin (MIFAP) in patients with prognostically unfavorable recurrent and refractory Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). METHODS: Forty-six patients (median age 43 years, range 18-63) with relapsed (n = 15) or refractory (n = 31) malignant lymphoma were enrolled (HD, n = 13; low-grade/transformed NHL, n = 4; high-grade NHL, n = 29). A total of 39 patients (85%) showed multiply relapsed diseases with a duration of prior remission of < 12 months (n = 8) or had lymphoma being resistant to prior chemotherapy (n = 31). The MIFAP therapy consisted of fludarabine (15 mg/m2, q. 12 h, day 1-4), cytarabine (50 mg/m2 by continuous infusion (CI) over 22 h, day 1-4), cisplatin (25 or 30 mg/m2 by CI over 24 h, day 1-4), and mitoxantrone (4 mg/m2, day 2-5). RESULTS: Thirteen patients (28%) achieved complete remission (CR) and 15 patients (33%) partial remission (PR), for an overall response (OR) rate of 61%. Twenty-two patients responding to MIFAP (10 CR, 12 PR) have been consolidated by high-dose therapy (HDT) with hematopoietic stem cell transplantation (SCT). After a median follow-up of 12 months, 16 patients are in continuous CR (CCR) (n = 14) or CCRu (unconfirmed) (n = 2). The median duration of event-free survival (EFS) and overall survival (OS) were 6.5 and 19.3 months, respectively. Probabilities of EFS and OS after 3 years were 19% and 40%. Responders consolidated by subsequent HDT showed rates for 3-year EFS and OS of 40% and 66%, respectively. Unfavorable prognostic factors for EFS by univariate analysis were refractory lymphoma and the presence of B-symptoms. Significant prognostic factors for OS were NHL, refractory lymphoma, B-symptoms, and bone marrow involvement. The major toxicities were leukocytopenia and thrombocytopenia of the World Health Organization (WHO) grade IV in nearly all courses (median duration 10 and 11 days). In contrast, non-hematological side effects were moderate, predominantly of WHO grades I and II. Treatment-related mortality with MIFAP was 4% (two patients with septicemia by Aspergillus fumigatus). CONCLUSIONS: MIFAP is an effective salvage protocol for patients with poor-risk recurrent or refractory HD and NHL. The observed toxicity seems to be acceptable considering the unfavorable prognosis and intensive pretreatment. The results in patients responding to MIFAP and afterwards undergoing HDT with autologous stem cell support are even comparable to those published in patients with prognostically more favorable diseases.

Sequential cycles of high-dose chemotherapy with dose escalation of carboplatin with or without paclitaxel supported by G-CSF mobilized peripheral blood progenitor cells: a phase I/II study in advanced ovarian cancer.

To assess high-dose carboplatin chemotherapy with or without paclitaxel with filgrastim mobilized peripheral blood progenitor cell (PBPC) support in a phase I/II study, a total of 21 patients with mostly chemonaive disease received four cycles of high-dose chemotherapy. Cycle 1 (cyclophosphamide, 6 g/m2) was followed by two cycles of carboplatin (1600 mg/m2 or 1800 mg/m2). Cycle 4 consisted of carboplatin (1600 mg/m2), etoposide (1600 mg/m2), and melphalan (140 mg/m2). Further chemotherapy intensification was achieved by adding paclitaxel (175 mg/m2) to all cycles with a fixed carboplatin dose (1600 mg/m2). Ototoxicity was dose-limiting for escalation of sequential cycles of carboplatin. Grade 2 and grade 3 ototoxicity, hearing loss not requiring a hearing aid, or hearing loss correctable with a hearing aid, was observed with carboplatin at 1800 mg/m2. The maximum tolerated dose (MTD) of sequential carboplatin, therefore, was identified in this study as 1600 mg/m2. After cycles 1, 2, 3 and 4 the median duration of leukopenia (<1.0x10(9)/l) was 7, 4, 4 and 6 days. Severe grade 3 and 4 infections were seen in only 7% of cycles. Of the 21 patients evaluable for disease response, 57% had complete remissions and 43% experienced partial remissions resulting in an overall response rate of 100%. The median progression-free survival is 25 (15-36) months, the median overall survival 36.5 (15-38) months. Most patients were suboptimally debulked or had bulky residual disease at the start of chemotherapy. Sequential high-dose chemotherapy to a maximum dose of 1600 mg/m2 carboplatin is effective and feasible. A randomized, prospective trial comparing sequential high-dose chemotherapy with optimal standard chemotherapy is now warranted.

The use of CD34+-selected PBPC after high-dose chemotherapy in breast cancer patients is associated with prolonged recovery time and increased infectious complications.

High-dose chemotherapy with autologous stem cell rescue can result in autotransplantation of tumor cells. A possible approach to reduce tumor cell contamination is the positive selection of CD34+ PBPC, but this might be associated with a prolonged recovery time as well as an increased risk of infectious complications because of the loss of committed progenitor cells. To investigate this aspect, we compared two sequentially treated cohorts of high-risk breast cancer patients. Both groups received the same high-dose chemotherapy regimen followed by autologous peripheral stem cell transplantation. Group I received CD34+-selected blood progenitor cells, and group II received nonselected blood progenitor cells. We compared these two identically treated groups with regard to recovery time, need for blood products, infectious complications, need for antibiotic treatment, and length of the transplantation-related hospital stay. We found a prolonged recovery time for neutrophils up to 0.5 x 10(9)/L (14 days in the selected group/10 days in the nonselected group) and platelets up to 30 x 10(9)/L (29/12 days), associated with an increased requirement for RBC transfusions (5/3 U) and platelet transfusions (10/2 U). The rate of severe infectious complications (2/0), the need for nonprophylactic antibiotic treatment (15/10), and the length of the hospital stay (25/21 days) in group I were also increased. We conclude that positive selection of PBPC should not be used routinely until randomized studies show a clear long-term benefit of using CD34+-selected stem cell products in breast cancer patients.

Bestfallanalysen zu 4 aktuellen unkonventionellen Behandlungsverfahren in der Onkologie.

Best-Case Analyses of 4 Current Unconventional Therapies in OncologyBest-case analyses are - under certain circumstances - a useful method to decide on the tumor-specific efficacy of unconventional treatments, without performing formal clinical studies and with limited expenditure. As part of the activities of the 'Arbeitsgruppe Biologische Krebstherapie', sponsored by the 'Deutsche Krebshilfe', an analysis and second-opinion judgement (according to internationally accepted standards) of their 'best cases' was offered to 36 manufacturers and users of unconventional cancer drugs and methods, who in public propagated these as effective cancer therapies. Only few of the approached offerers were both willing to cooperate and able to provide significant documentation for such an analysis. Therefore, only four best-case analyses could be performed completely. The work-up of the available documentation was not very convincing in all four cases, especially when considering that a positive selection from hundreds or even thousands of applications had taken place. The results of the analyses did not reveal any well-founded evidence for a tumor-specific effectiveness of the corresponding applications. The discrepancy between the offerers and the working group's judgements results especially from the circumstance that the majority of the treatments were not performed on patients with advanced tumor disease without any other conventional therapies, but additionally to established therapies or as an adjuvant treatment protocol. Other reasons were the obvious misjudgement of findings, the assessment of unimportant or unsuitable parameters, the misinterpretation of the probably normal development as a treatment success or also documentation inappropriate for evaluation.

Complete spontaneous remission in a patient with metastatic non-small-cell lung cancer. Case report, review of the literature, and discussion of possible biological pathways involved.

Spontaneous remission of cancer (SR) is defined as a complete or partial, temporary or permanent disappearance of all or at least some relevant parameters of a soundly diagnosed malignant disease without any medical treatment or with treatment that is considered inadequate to produce the resulting regression. We report the case of a 61-year-old man who presented with extensive metatastic disease five months after pneumonectomy for poorly differentiated large cell and polymorphic lung cancer. A vast metastatic tumour mass of the abdominal wall was confirmed histolologically and there was clinical and radiographic evidence of liver and lung metastases. Eight months later, the patient was operated on for a hernia, which had developed in the inguinal biopsy scar and the surgeon confirmed complete clinical SR of the abdominal wall metastases. Again five months later there was no longer any radiologic evidence of liver and lung metastases. Complete remission has persisted more than five years. Histology of the primary and of the abdominal metastases were reviewed by several independent pathologists. SR is an extremly rare event in lung cancer. This is the first documented case of clinically evident visceral metastases of a bronchiogenic adenocarcinoma developing after complete resection of the primary and then showing complete SR. The epidemiology of SR is reviewed and possible mechanisms involved in SR are discussed.

Effects of recombinant human thrombopoietin alone and in combination with erythropoietin and early-acting cytokines on human mobilized purified CD34+ progenitor cells cultured in serum-depleted medium.

The effects of recombinant thrombopoietin (TPO) alone and in combination with erythropoietin (EPO) and early-acting cytokines such as interleukin 3 (IL-3), stem cell factor (SCF) and GM-CSF on highly purified mobilized human CD34+ progenitor cells were studied in a serum-depleted culture system. Eight leukapheresis samples were cultured for seven days and analyzed; aliquots were replated and re-evaluated on day 12. Three-color flow cytometry was used together with morphologic analysis to determine proliferation and megakaryocytic or erythroid maturation. TPO alone was sufficient for cell survival and proliferation in serum-depleted medium. In the absence of other growth factors, almost all CD34+ cells differentiated along the megakaryocytic pathway within 12 days. Concomitantly, the progenitor cells gradually acquired the morphologic features of mature megakaryocytes. After exposure to TPO for one week, 50% of the cells still expressed CD34; by day 12 the remaining CD34+ cells (11%) were all coexpressing CD41. TPO alone did not support proliferation of glycophorin-A-positive cells. The addition of TPO to early-acting cytokines (EPO, GM-CSF, SCF and/or IL-3) not only increased the overall megakaryocyte expansion, but also generated a different maturation pattern of the CD41+ megakaryocyte progenitors. It further doubled the number of erythroid cells and c-kit+ cells in the second week of culture. Interestingly, the overall number of CD34+ cells was increased about fivefold when TPO was added to the early-acting cytokines, with a marked expansion of the CD34+/CD41+ and CD34+/CD117+ subpopulations. TPO can augment the pool of committed progenitors, thereby increasing the number of its own target cells and the number of EPO-responsive cells. These properties make TPO an interesting cytokine for the ex vivo expansion of human progenitor cells.

LW/SO cell line: a tool for studying the phenotypical characterization and commitment of hematopoietic stem cells.

We report our observations with the cell line LW/SO, which was recently derived from the bone marrow of a patient with acute myeloid leukemia. Based on the morphological and histochemical examination, the leukemic cells were classified primarily as FAB type M4. However, 2 years later, in relapse, the cells changed their morphology and were hence specified as FAB type M2 (slightly positive for acid phosphatase and Sudan black). The cells established have now been in culture for approximately 11 months and display nearly 100% CD4/5/7/15/25/71/120a,b at varying densities. Some of them spontaneously and reversibly become either CD34 + /38- or CD34 - /38+, yet the majority of the cells remain negative for both. All attempts to separate the cells with a distinct phenotype by limiting dilution or sorting through a flow cytometer failed repeatedly. The subsets, enriched up to 98% (regardless of their primary immunophenotype CD34 - / 38-, CD34 + /38-, or CD34 - /38+), soon displayed a phenotypical constellation similar to that before sorting. The ratio of CD34- to CD34+ seems to be influenced by the cell density: The greater the cell-to-cell contact, the lower the percentage of CD34-expressing cells. Some of the cells apparently differentiate into T-cell phenotype and acquire CD3 and T-cell receptor (TCR) alpha/beta molecules. While the quantity of CD34-expressing cells significantly increased in the presence of dexamethasone (10(-7) M), and some of them additionally acquired CD33 antigen, the percentage of CD3-positive cells was enhanced by adding 1% DMSO in medium. In contrast, cytokines such as IL-1, IL-2, IL-3, IL-4, IL-6, G-CSF, GM-CSF, or SCF (c-kit ligand) altered neither the proliferation capacity nor the phenotypical constellation of LW/SO cells (each tested alone). Although normal karyotype was obtained from the bone marrow cells, the LW/SO cells revealed a homogeneous chromosomal composition of 45, X, -X, der(9) inv(9) (p12q13) del(9) (p22?). These data suggested that LW/SO cells might be the leukemic counterpart of putative pre-CD34-positive progenitors. In order to substantiate this assumption, we analyzed the expression of other so-called T-cell markers on CD34+ cells from peripheral blood stem cell aphereses of five patients who later underwent high-dose chemotherapy and subsequent stem cell retransfusion. These data clearly revealed that a considerable amount of CD34+ hematopoietic progenitors co-express CD2/4/(5)/(7)/25 at an early stage of differentiation, and support the notion that CD34-negative LW/SO cells with the surface markers CD4/5/7/25 are probably phenotypical representatives of pluripotent stem cell. Hence, not all CD34-negative populations with so-called T-cell surface markers should be considered T-cells; some may constitute the ancestor of CD34 antigen-expressing progenitors.

Randomised comparison of CHOEP versus alternating hCHOP/IVEP for high-grade non-Hodgkin's lymphomas: treatment results and prognostic factor analysis in a multi-centre trial.

BACKGROUND: With CHOP, the standard protocol of recent decades, about 30% of long-term survival has been reported. A number of studies using more aggressive multidrug regimens or alternating chemotherapies have recently suggested higher CR rates and increased survival. In 1989 we reported similar results with a combined-modality treatment administering 6 cycles of CHOP supplemented with etoposide and an involved field irradiation for patients in PR or CR. PATIENTS AND METHODS: To confirm the efficacy of this approach, we initiated a prospective randomised trial comparing 4 cycles of CHOP-VP16 (CHOEP) with 4 cycles of two alternating regimens, 'hCHOP and IVEP'. One hundred seventy-five patients with high-grade non-Hodgkin's lymphomas stages II-IV were stratified for age, stage and LDH and randomised to receive either four cycles of cyclophosphamide, doxorubicin, vincristine, etoposide, prednisolone (CHOEP) in arm A or four cycles of chemotherapy with a dose-intensified CHOP (hCHOP) alternating with ifosfamide, etoposide, vindesine, prednisolone (IVEP) in arm B. After four cycles of chemotherapy an involved field irradiation with a total dose of 35 Gy was given to all patients demonstrated to be in complete or partial remission. RESULTS: Of the 185 randomised patients, 175 were eligible and 171 evaluable for response and survival. One hundred forty-six of the 171 patients (85%) achieved complete remission (CR) with 87% and 84% CRs in arms A and B, respectively. With a median follow-up of 36 months the estimated overall survival at 2 years is 66% and 73% for arms A and B, respectively. The percentage of all patients in first CR is estimated to be 59% and 55% at 2 years for arms A and B, respectively. None of the differences in CR rate, survival, or relapse-free survival are statistically significant. Multivariate analysis of subgroups incorporating the factors of sex, age, performance status, stage, B symptoms, bulky disease, LDH and histology revealed that only stage and LDH were factors which independently affected outcome. The estimated 2-year survival rate of patients with stages II, III and IV is predicted to be 84%, 62% and 52%, respectively. Patients with LDH > 250 U/l have an estimated survival of 52% at 2 years versus 84% for patients with LDH < or = 250 U/l. According to the newly proposed international score system, the 2-year survival was 81% for low-risk-, 64% for low intermediate risk-, 50% for high intermediate risk-, and 43% for high-risk patients. The toxicity in both arms was tolerable. Three patients died of treatment-related causes (2 in arm A, 1 in arm B). The main toxicity was haematological with 75% of patients suffering from grades 3 or 4 neutropenia at some point during treatment. CONCLUSIONS: We observed no superior benefit for alternating regimens, and conclude that both are effective treatment protocols for aggressive histologic-type malignant lymphomas. The results obtained with four cycles of poly-chemotherapy followed by an involved field irradiation are comparable to programs using more aggressive and/or prolonged chemotherapy.

Regulation of the density of the stem cell factor receptor (c-kit) by tumor necrosis factor alpha on a human myeloid cell line.

The GM/SO cell line bears a high level of stem cell factor receptors (SCF-R) i.e. c-kit protein, and therefore constitutes a potential model for studying the regulation of this crucial receptor on myeloid cells. In this study we evaluated the effect of tumor necrosis factor alpha (TNF-alpha) on the expression of SCF-R by flow cytometry. In contrast to 1 hour of preincubation, the experiments carried out after 24 hours preincubation revealed that TNF-alpha, if added alone, reduced the density of SCF-R on GM/SO cells in a dose-dependent manner. However, if combined with GM-CSF, which per se downregulates the SCF-R on these cells as well, TNF-alpha antagonized the effect of GM-CSF and slightly increased the density of SCF-R. Yet the cells incubated for 24 hours in medium without cytokines invariably expressed a higher level of SCF-R than the cells incubated in the presence of TNF-alpha and GM-CSF, either alone or in combination. In contrast to these cytokines, stem cell factor (SCF), which was also tested simultaneously in all experiments, downregulated its own natural receptor on these cells also after a preincubation of 1 hour. Furthermore, prolonged exposure of GM/SO cells to TNF-alpha for 5-7 days yielded a monocyte-macrophage-like morphology of some cells as these cells displayed an apparent glass and plastic adherence. In contrast, no such morphological changes could be observed in the presence of GM-CSF or SCF.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces the density of stem cell factor receptors (c-kit oncogene product) on a GM-CSF-dependent human myeloid cell line.

By employing a monoclonal antibody against the stem cell factor receptor (SCF-R), c-kit oncogene product, we analysed in flow cytometric technique the density of SCF-R on GM/SO cells which were incubated under various culture conditions. These experiments revealed that there is an inverse correlation between the SCF-R density on the cells and the doses of granulocyte-macrophage colony-stimulating factor (GM-CSF) in culture medium; the lower the dose, the higher the density of SCF-R on the cells. More detailed analyses showed that, in contrast to SCF which rapidly downregulates its own receptor, GM-CSF does not alter the measurable level of SCF-R in an exposition period of 60 minutes, which suggests that the internalization or shedding of the receptor is not the mechanism of action. Since the most striking difference regarding density of SCF-R between GM-CSF-treated and untreated cells was observed on day 2, the modulation of c-kit oncogene protein by GM-CSF likely occur prior to expression of protein onto the cell surface. In order to exclude the possibility that altered cell viability due to insufficient GM-CSF content in culture medium might be responsible for the increased SCF-R densities on GM-CSF-dependent cells, we subsequently generated a GM-CSF-independent subclone which still responded to GM-CSF as well as the dependent did. The experiments carried out with this subclone confirmed the results presented above. Thus our data suggest that GM-CSF is directly involved in the regulation of SCF receptor density on GM/SO cells.