Clonal chromosomal abnormalities in the stem cell compartment of patients with acute myeloid leukemia in morphological complete remission

Acute myeloid leukemia arises from the clonal expansion of a malignant transformed progenitor cell. Despite intensive chemotherapy, final disease eradication is achieved by a small proportion of cases only and 50-70% of adults with AML will ultimately relapse and die from their disease. Hence residual disease below the level of morphological detectability must be assumed in clinical and morphological complete remission. CD34+/CD38- and CD34+/CD38+ subpopulations of seven patients in morphological complete remission were isolated by FACS (purity >98%) and were analyzed by conventional cytogenetics or FISH for chromosomal aberrations. In five of seven patients, clonal chromosomal abnormalities were detected in the CD34+/CD38+ subpopulation and in one patient with AML M2 (add (2)(q37)) in the most immature CD34+/CD38- stem cell compartment. One patient with AML M4Eo (inv(16),+8), showed a normal karyotype by conventional cytogenetic analysis, whereas four of 15 metaphases of the sorted CD34+/CD38+ subpopulation revealed the inversion 16. These observations underline that leukemic cells can survive intensive chemotherapy in the niche of the stem cell compartment. In some patients the sensitivity for the detection of persistent leukemic cells seems to be higher in FACS-sorted subpopulations than conventional cytogenetic analysis of the unseparated bone marrow. Immunophenotyping revealed minimal residual disease in four of the patients. Functional analysis has to be performed to investigate the leukemogenic potential of these residual cells.

Multicenter phase II study of fludarabine phosphate for patients with newly diagnosed lymphoplasmacytoid lymphoma, Waldenström's macroglobulinemia, and mantle-cell lymphoma

PURPOSE

Fludarabine phosphate (F-AMP) has significant activity in follicular lymphoma and in B-cell chronic lymphatic leukemia, where it has demonstrated high complete response (CR) rates. Lymphoplasmacytoid (LPC) lymphoma, Waldenstrom's macroglobulinemia (WM), and mantle-cell lymphoma (MCL) also present with advanced-stage disease and are incurable with standard alkylator-based chemotherapy. A phase II trial was undertaken to determine the activity of F-AMP in patients newly diagnosed with these diseases.

PATIENTS AND METHODS

Between 1992 and 1996, 78 patients (aged 18 to 75 years) received intravenous F-AMP (25 mg/m2/d for 5 days, every 4 weeks) until maximum response, plus two further cycles as consolidation. The primary end point was response rate; secondary end points included time to progression (TTP), duration of response, and overall survival (OS).

RESULTS

Forty-four (62%) of 71 assessable patients had a response to F-AMP (LPC lymphoma, 63%; WM, 79%; MCL, 41%); the CR rate was 15%. At a median follow-up of 1.5 years, 19 of 44 responding patients have had progression of lymphoma; the median duration of response was 2.5 years. The median survival has not yet been reached. There was no significant difference in the duration of response or OS between patients with different histologies; TTP was shorter in patients with MCL (P = .015). Myelosuppression was relatively common, and the treatment-related mortality (TRM) was 5%, mostly associated with pancytopenia and infection.

CONCLUSION

Single-agent fludarabine phosphate is active in previously untreated LPC lymphoma and WM, with only moderate activity in MCL. However, the CR rate is low, and the TRM is relatively high. Its role in combination chemotherapy remains to be demonstrated.

TGF-beta and its receptor complex in leukemic B-cell precursors

Transforming growth factor beta (TGF-beta) is a highly conserved peptide with growth-inhibitory activity in multiple normal and transformed cell types. Signal transduction is mediated through the receptor complex, consisting of two active seronine or threonine kinases (TGF-beta-receptor I and II) and the receptor-associated proteins betaglycan (TGF-beta-receptor III) and endoglin. In this study, we assessed the analysis of the role of TGF-beta and the transcription of the genes for TGF-beta and its receptor in highly purified leukemic B-cell precursors (BCPs) of patients with common acute lymphoblastic leukemia (cALL). Leukemic BCPs were positive for gene transcription of TGF-beta (9/9), the TGF-beta-receptor I (9/9), the TGF-beta-receptor II (6/6), betaglycan (5/6), and endoglin (6/6). Incubation with TGF-beta significantly reduced the cell viability of leukemic BCPs by a mean of 45% (p = 0.0009). The reduction of cell viability was associated with the induction of apoptosis by a mean of 31%. TGF-beta caused significant suppression of the S phase (p = 0.002) and accumulation in the G0/G1 phase (p = 0.0005). It also reduced expression of the adhesion surface receptor CD18 and the Fas antigen CD95 from 58% to 40% and from 48% to 27%, respectively. The data indicate that TGF-beta is a negative growth signal in leukemic BCPs and point to an additional role of TGF-beta as an immunomodulatory cytokine, suggesting a complex role of TGF-beta in the leukemogenesis of cALL.

Combination of aclarubicin and etoposide for the treatment of advanced acute myeloid leukemia: results of a prospective multicenter phase II trial. German AML Cooperative Group

In order to develop new strategies for the treatment of relapsed or refractory acute myeloid leukemia, the German AML Cooperative Group performed a prospective multicenter phase II study to evaluate the antileukemic efficacy of aclarubicin 60 mg/m2/day and etoposide 100 mg/m2/day each given for 5 days. Of 37 heavily pretreated evaluable patients (median age 42 years, range 18-81) 15 (40%) achieved a remission after one or two courses of treatment consisting of nine complete (24%) and six partial remissions (16%). Fourteen (38%) cases were non-responders and eight (22%) patients suffered from early deaths. Disease-free survival for patients in remission and overall survival were 3.2 months each. The median duration of critical neutropenia <500/microl was 27 days. The most frequent non-hematologic side-effects were stomatitis (WHO III/IV, 48%), infections (40%), nausea/vomiting (26%) and diarrhea (24%). Cardiac toxicity was mild. This study suggests a substantial antileukemic efficacy and an acceptable toxicity of aclarubicin in combination with etoposide in heavily pretreated patients with advanced acute myeloid leukemia, and warrants further evaluations in a more favorable stage of the disease.

Structure of Bcl-1 and IgH-CDR3 rearrangements as clonal markers in mantle cell lymphomas

Mantle cell lymphoma represent a clinicopathologically distinct entity of malignant non-Hodgkin's lymphoma (NHL) and are characterized by a specific chromosomal translocation t(11;14)(q13;q32) involving the cyclin D1 gene also designated as bcl-1/PRAD1 gene on chromosome 11 and the heavy chain immunoglobulin joining region on chromosome 14. We have established a PCR method to amplify t(11;14) junctional sequences in DNA from fresh frozen and paraffin-embedded tissue by bcl-1-specific primers in combination with a consensus immunoglobulin JH primer. A total of 65 cases histologically classified as mantle cell lymphoma (MCL) were analyzed for the presence of a t(11;14) translocation and monoclonal IgH-CDR3 rearrangements. From 26 patients with classical MCL and three cases with the anaplastic variant of MCL fresh frozen biopsy material was available for DNA extraction. We detected a bcl-1/JH rearrangement in 12 out of 29 samples (41%). In 36 cases paraffin-embedded lymph node tissue was the only source of DNA. In this material we found a bcl-1/JH rearrangement in six out of 31 samples with intact DNA (20%). To confirm the specificity of the PCR and to determine the bcl-1/JH junctional region sequences as clone-specific marker in individual patients we characterized the junctional DNA sequences by direct PCR sequencing in 16 cases. Interestingly we found that six bcl-1/JH junctions harbored DH segments in their N regions indicating that bcl-1/JH rearrangements can occur in a later stage of B cell ontogeny during which the complete VH to DH-JH joining or VH-replacement takes place. To investigate the suitability of IgH-CDR3 as sensitive molecular marker for those MCL patients in which a t(11;14) translocation can not easily be amplified, we additionally analysed 60 cases for the presence of monoclonally rearranged IgH genes by IgH-CDR3-PCR. A monoclonal IgH-CDR3 PCR product could be identified in 24 out of 29 fresh frozen samples (79%) whereas only 11 out of 31 samples (36%) with paraffin-derived DNA were positive. We demonstrate that automated fluorescence detection of monoclonal IgH-CDR3 PCR products allows the rapid and sensitive monitoring of minimal residual disease also in cases that lack a PCR amplifiable t(11;14) translocation. In combination with allele-specific primers the procedure may improve current experimental approaches for detection of occult MCL cells at initial staging and residual disease during and after therapy.

Oral cytarabine ocfosfate in acute myeloid leukemia and non-Hodgkin's lymphoma--phase I/II studies and pharmacokinetics

Cytosine arabinoside (AraC) is rapidly inactivated via systemic deamination with half-lives ranging from 1 h (i.v.) to 4 h (s.c.) -- and cannot be applied orally due to its hydrophilic properties. These limitations might be overcome by YNK01 -- a lipophilic prodrug of AraC -- that is resistant to deoxycytidine deaminase and can be applied orally. In the present study the therapeutic activity, side-effects and pharmacokinetics of YNK01 were evaluated in a phase I/II study including patients with relapsed or refractory acute myeloid leukemia (AML) (n=23) or low-grade non-Hodgkin's lymphoma (NHL) (n=20). YNK01 was given by 14 day cycles with escalating doses starting with a daily dose of 50 mg/m2 (equivalent to 20 mg/m2 AraC on a molar basis). The maximum tolerated dose was reached at the 600 mg/m2 dose level with WHO grade 3-4 diarrhoea as the main toxicity. In the 23 patients with AML two complete remissions, four partial remissions and three patients with stable disease were observed. In the 23 patients with AML two complete remissions, four partial remissions and three patients with NHL two cases reached partial remission and six other patients mainained stable disease. Pharmacokinetic evaluations were performed during 34 treatment cycles in 28 patients. The data suggest that YNK01 was absorbed in the distal part of the small intestine and taken up into hepatocytes. After hepatic psi and subsequent beta-oxydation of YNK01 the released AraC (and its deamination product AraU) appeared in the systemic circulation. Time of maximum concentration (h), half-life (h) and area under the curve (ng x h/ml, at the 1200 mg dose level) were as follows (VC variation coefficient) YNK01: 1.0 (0.58), 10.1 (0.43), 12622 (0.65); AraC: 23.2 (0.57), 22.6 (0.36), 3496 (0.76); AraU: 19.2 (0.58) 22.3 (0.33) 15441 (0.66). Of the total dose of YNK01 15.8% was absorbed and metabolized to AraC and AraU, defining the metabolic bioavailability of this prodrug. A linear relationship was observed between YNK01 dose and YNK01 AUC and AraC AUC over the whole dose range tested. AraC was released from hepatocytes over a prolonged period of time resulting in long lasting plasma levels similar to a continuous i.v. infusion. After administration of YNK01 at a dosage of 100-150 mg/m2 plasma levels of AraC were comparable to those achieved after low-dose AraC treatment (20 mg/m2) while at doses of YNK01 of 450-600 mg/m2 concentrations of standard-dose AraC (100 mg/m2) were obtained. We conclude that YNK01 shows considerable activity against relapsed and refractory AML and NHL and that its pharmacokinetic properties offers advantages in comparison to (standard) i.v. or s.c. AraC in clinical practice.

Cell lineage specific involvement in acute promyelocytic leukaemia (APL) using a combination of May-Grünwald-Giemsa staining and fluorescence in situ hybridization techniques for the detection of the translocation t(15;17)(q22;q12)

Acute promyelocytic leukaemia (APL) is strongly associated with the translocation t(15;17) which therefore provides a reliable marker to assess the potential involvement of different cell lineages. Six cases with morphologically, cytogenetically and molecularly proven APL were analysed at diagnosis or relapse by combining fluorescence in situ hybridization (FISH) with standard May-Grünwald-Giemsa (MGG) staining at the single cell level on bone marrow and blood smears. With the FICTION technique, combining immunophenotyping with FISH, haemopoietic precursor cells were identified using monoclonal antibodies against CD34, B- and T-lymphocytes could be identified with CD19 and CD3. In addition, HLA-DR-positive cells were studied for the presence of t(15;17). Morphologically identified myeloblasts were relocated on the smear after FISH and were found to be PML/RARA positive in 91%, abnormal promyelocytes in 97%. In contrast, a positive signal was obtained in only 18% of PMN. Erythroblasts, lymphocytes and plasma cells did not show a PML/RARA rearrangement. Accordingly, all cells expressing CD3 or CD19 were PML/RARA negative. CD34 positive precursor cells identified by FICTION were PML/RARA positive in 97%. HLA-DR-positive cells contained a PML/RARA rearrangement in 24% of cells in one case and were negative in the two other cases investigated. These data indicate that APL appears to originate from a level of haemopoietic precursor cells but is restricted to the myeloid lineage. The low proportion of PML/RARA-positive PMN points to the impairment of blast cell differentiation beyond the promyelocyte stage but also emphasizes the existence of normal residual haemopoietic stem cells from which PML/RARA-negative PMN must be derived.

Induction combination chemotherapy with docetaxel and carboplatin in advanced non-small-cell lung cancer

BACKGROUND

Results in the therapy of locally advanced non-small-cell lung cancer (NSCLC) by operation and/or irradiation only are poor. To improve the long-term prognosis a systemic induction chemotherapy may be successful in reducing local tumor burden and eliminating micrometastases. The efficacy of preoperative docetaxel-carboplatin combination chemotherapy was studied in a phase-II study for NSCLC stage IIIB.

METHODS

15 patients with functionally operable stage IIIB NSCLC (10 squamous-cell, 4 adeno, 1 large-cell) were enrolled to receive 4 cycles of docetaxel (100 mg/m2, day 1) and carboplatin (AUC 7.5, day 2) on an outpatient basis with G-CSF support after cycle 1 and were subsequently evaluated for surgery. Postoperatively the patients were irradiated with 50 Gy (R0-resection) or 60 Gy (R1-resection).

RESULTS

Acceptable hematologic and non-hematologic toxicity was observed. On an intent-to-treat basis, 14 patients were evaluable for radiological response after 4 cycles of chemotherapy (1 patient still on therapy): 11/14 patients had radiological response of > or = 50%, 1/14 progressive disease, 2 exclusions because of toxic death (1 patient) and capillary leak (1 patient). Of 11 patients evaluated for surgery, 9 patients were resected, 1 patient is awaiting operation, 1 patient received radiotherapy because of an esophageal fistula. By histological findings a downstaging was achieved in 6/9 resected patients: histological complete response (CR) in 4 patients, partial response (PR) in 2, and no response in 3. With a mean follow-up of 8.1 months (excluding 1 patient in early postop course), 5/5 R0 and histological responders are alive and disease-free. Of the 3 histological non-responders, 1 patient (R1/2 resection) died of respiratory failure, 2 patients (1 R1 and 1 R0) of distant metastases.

CONCLUSION

Outpatient therapy with docetaxel/carboplatin chemotherapy is effective in downstaging patients with NSCLC, toxicity is acceptable. Histological response may be the most important prognostic factor. The early results of this phase II study encourage evaluation of the long-term benefit within a prospective randomized phase III study.

Granulocyte colony-stimulating factor shortens duration of critical neutropenia and prolongs disease-free survival after sequential high-dose cytosine arabinoside and mitoxantrone (S-HAM) salvage therapy for refractory and relapsed acute myeloid leukemia. German AML Cooperative Group

Patients with primary refractory or relapsed acute myeloid leukemia (AML) who undergo intensive salvage chemotherapy carry a high risk of treatment failure due to infectious complications and early relapses. The study presented here assessed the effect of granulocyte colony-stimulating factor (G-CSF) on the duration of post-treatment neutropenia, the incidence of infection-related deaths, and the disease-free and overall survival. Sixty-eight evaluable patients with relapsed and refractory AML received G-CSF 5 microg/kg per day subcutaneously starting 2 days after the completion of salvage treatment with the S-HAM regimen, consisting of high-dose cytosine arabinoside twice daily on days 1, 2, 8, and 9 and mitoxantrone on days 3, 4, 10, and 11. Ninety-one patients who were treated with the identical S-HAM regimen but without G-CSF support during a preceding study served as controls. The application of G-CSF resulted in a significant shortening of critical neutropenia of less than 500 microl (36 vs. 40 days; p = 0.008), which translated into a trend towards a lower early death rate (21% vs. 30%) and an increase of complete remissions (56% vs. 47%, p=0.11). In patients younger than 60 years a significant prolongation of time to treatment failure (159 vs. 93 days, p=0.038) and of duration of disease-free survival (203 vs. 97 days, p=0.003) was observed. These results indicate a beneficial effect of G-CSF on early mortality as well as on long-term outcome when administered after S-HAM salvage therapy for advanced AML.

Partial tandem duplications of the MLL gene are detectable in peripheral blood and bone marrow of nearly all healthy donors

Partial tandem duplication within the MLL gene has recently been described as a novel genetic alteration in acute myeloid leukemia (AML). It has been associated with trisomy of chromosome 11, but was also identified in AML patients with normal karyotypes. The current study was performed to investigate whether MLL duplications are restricted to AML, and hence whether they may also occur in normal hematopoietic cells. MLL-duplication transcripts were analyzed by nested reverse-transcriptase polymerase chain reaction (RT-PCR) in peripheral blood in two groups of 45 and 20 patients, respectively, as well as in two bone marrow samples from healthy volunteers. Duplications were detected in two independent nested RT-PCR experiments in the peripheral blood samples of 38 of 45 (84%) and 20 of 20 (100%) of the two groups and in both bone marrow samples. On this basis, MLL duplications seem to occur frequently in a subset of cells in normal hematopoiesis. The type of partially duplicated MLL transcripts varied substantially. Three transcripts were identical to those known from AML. In addition, four new transcripts were characterized. Three of these four were in frame and potentially translatable. MLL duplications were also detected by seminested genomic PCR with intron 9- and intron 1-specific primers in 20 of 20 peripheral blood samples studied, indicating that the duplications are genomically fixed at the DNA level and are not an RT-PCR artifact. In summary, MLL duplications are regularly generated by homologous ALU recombination in a small number of hematopoietic cells of most or even all healthy donors. These data suggest that MLL duplications are not implicated in the malignant transformation in AML, or alternatively, that only a few cells will acquire additional oncogenic mutations necessary to establish the malignant phenotype of AML.

Elevated serum level of soluble CD23 precedes development of B-non-Hodgkin's lymphoma in SIV-infected Rhesus monkeys

Patients with HIV infection are at high risk for the development of high-grade B-non-Hodgkin's lymphoma (B-NHL). The aim of this study was identification of a predictive diagnostic marker for HIV-associated B-cell lymphomas, using simian-immunodeficiency-virus (SIV)-infected Rhesus monkeys as a well-established in vivo model of HIV-associated lymphomagenesis. We infected 26 monkeys (Macaca mulatta) with SIVmax and measured serum levels of sCD23 longitudinally until necropsy. Of the 26 monkeys, 9 developed high-grade B-NHL, which was preceded by lymphadenopathy (NHL+/LA+) (group 1). Among the 17 animals that remained without clinical evidence of lymphoma during the observation period, 8 developed LA (group 2) and 9 were NHL- and LA-negative (NHL-/LA-) (group 3). Elevation of sCD23 serum levels preceded B-cell lymphoma development, with a median of 44 U/ml in group 1 vs. 7 U/ml and 8 U/ml in groups 2 and 3 respectively, 32 weeks after infection. Differences in the serum level of sCD23 between group 1 vs. groups 2 and 3 became statistically significant 32 to 56 weeks after infection. At necropsy, serum levels of sCD23 were significantly higher in group 1 than in group 2 or group 3; 6/6 samples of SIV-associated B-NHL were positive for gene transcription of CD23 and its receptor CD21 as assessed by RT-PCR. The data point to a potential role of sCD23 as a predictive marker for the development of HIV-associated B-NHL. Moreover, the in vivo model of SIV-infected monkeys suggests the possibility of exactly analyzing the pathobiological role of sCD23 in the lymphomagenesis of SIV-associated B-NHL.

Failure of fluconazole prophylaxis to reduce mortality or the requirement of systemic amphotericin B therapy during treatment for refractory acute myeloid leukemia: results of a prospective randomized phase III study. German AML Cooperative Group

BACKGROUND

Invasive fungal infections have increasingly become a matter of concern with regard to patients receiving intensive myelosuppressive therapy for hematologic malignancies. Such infections, especially prolonged neutropenia systemic fungal infections, may contribute substantially to infectious complications and early death. Measures for early detection and effective prophylactic strategies using active and nontoxic antifungal agents are therefore urgently needed.

METHODS

The current randomized study was initiated to assess the efficacy of oral fluconazole as systemic antifungal prophylaxis for high risk patients with recurrent acute myeloid leukemia undergoing intensive salvage therapy.

RESULTS

Of 68 fully evaluable patients, 36 were randomized to fluconazole in addition to standard prophylaxis with oral co-trimoxazol, colistin sulphate, and amphotericin B suspension, and 32 were randomized to standard prophylaxis only. No major differences between the two groups were observed in the number of episodes of fever of unknown origin (61% vs. 50%) or clinically defined infections (56% vs. 50%). Microbiologically defined infections were more frequent in the fluconazole group (50% vs. 31%), mainly due to a higher incidence of bacteremias (42% vs. 22%). There were two cases of proven invasive fungal infections in each group. Systemic amphotericin B was administered more frequently to patients receiving fluconazole prophylaxis (56% vs. 28%). Fluconazole prophylaxis had no impact on the rate of early death or overall survival.

CONCLUSIONS

For patients with high risk recurrent acute myeloid leukemia undergoing intensive salvage therapy, antifungal prophylaxis with fluconazole was not superior to standard prophylaxis only.

Superiority of high-dose over intermediate-dose cytosine arabinoside in the treatment of patients with high-risk acute myeloid leukemia: results of an age-adjusted prospective randomized comparison

Although cytosine arabinoside (AraC) represents the most effective single agent in the treatment of adults with acute myeloid leukemia (AML) when given at doses exceeding 200 to 500 mg per application, its optimal dosage is still a matter of controversial discussion. While pharmacokinetic investigations suggest that the AraC-activating enzyme deoxycytidine kinase is saturated at drug concentrations achieved by short-term infusion of 0.5 to 1.0 g/m2 AraC and that higher doses are therefore not more effective, recent evidence indicates that additional mechanisms of AraC cytotoxicity may exist which could be enhanced by further dose escalation. In order to test this thesis in the clinical setting, a prospective randomized comparison of high-dose (HD-AraC) vs intermediate-dose (ID-AraC) AraC was carried out in patients with refractory or relapsed AML on the basis of the sequential high-dose AraC and mitoxantrone regimen (S-HAM). AraC was given as a 3-h infusion q 12 h on days 1, 2, 8 and 9. Patients younger than 60 years were randomized to AraC doses of 3.0 g/m2 vs 1.0 g/m2 while older patients received either 1.0 g/m2 or 0.5 g/m2 per single dose. Mitoxantrone was given to all patients on days 3, 4, 10 and 11 at a daily dose of 10 mg/m2. Randomization was stratified for primary refractoriness against induction therapy and length of first remission in relapsed patients. From 186 evaluable patients, 88 (47%) and 10 cases (5%) achieved a complete (CR) or partial (PR) remission, 39 patients (21%) had persisting leukemia (non-response (NR)), and 49 cases (26%) died within 6 weeks after the start of therapy (early death (ED)). In patients younger than 60 years the higher dose level resulted in a significant reduction of NR (12% vs 31%; ordinal chi2 test: P = 0.01) but also a higher rate of ED (32% vs 17%) thus leading to a marginally higher CR rate only (52% vs 45%). Within the subgroup of patients with refractory AML the tendency towards a higher CR rate after HD-AraC was more pronounced (46% vs 26%; P = 0.045). In patients older than 60 years, corresponding though less evident differences were observed with a higher rate of NR in the lower dose group (26% vs 16%) and ED occurring more frequently after higher doses (36% vs 26%). These data indicate that HD-AraC reveals a significantly higher antileukemic efficacy than ID-AraC as expressed by a significant reduction of failure from NR. This advantage, however, does not fully translate into an increase in remission rate due to a higher incidence of ED after HD-AraC predominantly from uncontrolled infections. In order to take full advantage of the higher antileukemic activity of HD-AraC an improvement of supportive care and infection control is warranted.

Interferon alfa for the treatment of follicular lymphomas

PURPOSE

Recombinant human interferon alfa (rIFN-alpha) has demonstrated significant activity against follicular lymphomas when applied as salvage treatment after the failure of conventional therapy. It has also been shown to exhibit synergistic antitumor activity when given simultaneously with certain cytostatic agents.

PATIENTS AND METHODS

Against this background, two major strategies were followed to incorporate rIFN-alpha into the first-line treatment of follicular lymphomas: application simultaneously with initial cytotoxic chemotherapy and application as maintenance treatment after successful initial chemotherapy.

RESULTS

Of the five prospective randomized trials performed to assess the activity of rIFN-alpha in combination with initial chemotherapy versus the activity of chemotherapy alone, three studies showed that rIFN-alpha plus chemotherapy yielded no beneficial effect on remission rate, remission duration, or overall survival. In all three of these trials, chemotherapy consisted of a single alkylating agent. In contrast, a significant improvement in remission rate and remission duration was observed in two studies when rIFN-alpha was combined with anthracycline-containing regimens. Five prospective randomized studies have evaluated the role of rIFN-alpha as maintenance therapy after successful cytoreductive chemotherapy. Four of these studies have either found no significant prolongation of the disease-free interval or shown significant improvement in disease-free survival only in patients achieving a complete remission with initial cytoreductive treatment. In all four studies, relatively low doses of rIFN-alpha were administered for a limited time. A different outcome emerged in the fifth study, by the German Low Grade Lymphoma Study Group, in which patients received higher doses of rIFN-alpha with no restriction on duration of therapy. Patients treated with rIFN-alpha had a significantly prolonged median progression-free interval (30 versus 19 months), and at 4 years, 45% of patients receiving rIFN-alpha maintenance therapy remained relapse-free, compared with 26% of patients in the untreated control group (P = 0.003).

CONCLUSION

Collectively, these data demonstrate that rIFN-alpha adds substantially to the treatment of follicular lymphomas either when combined with anthracycline-containing cytoreductive chemotherapy or when given as long-term maintenance therapy.

MLL and CALM are fused to AF10 in morphologically distinct subsets of acute leukemia with translocation t(10;11): both rearrangements are associated with a poor prognosis

The translocation t(10;11)(p13;q14) has been observed in acute lymphoblastic leukemia (ALL) as well as acute myeloid leukemia (AML). A recent study showed a MLL/AF10 fusion in all cases of AML with t(10;11) and various breakpoints on chromosome 11 ranging from q13 to q23. We recently cloned CALM (Clathrin Assembly Lymphoid Myeloid leukemia gene), the fusion partner of AF10 at 11q14 in the monocytic cell line U937. To further define the role of these genes in acute leukemias, 10 cases (9 AML and 1 ALL) with cytogenetically proven t(10;11)(p12-14;q13-21) and well-characterized morphology, immunophenotype, and clinical course were analyzed. Interphase fluorescence in situ hybridization (FISH) was performed with 2 YACs flanking the CALM region, a YAC contig of the MLL region, and a YAC spanning the AF10 breakpoint. Rearrangement of at least one of these genes was detected in all cases with balanced t(10;11). In 4 cases, including 3 AML with immature morphology (1 AML-M0 and 2 AML-M1) and 1 ALL, the signals of the CALM YACS were separated in interphase cells, indicating a translocation breakpoint within the CALM region. MLL was rearranged in 3 AML with myelomonocytic differentiation (2 AML-M2 and 1 AML-M5), including 1 secondary AML. In all 3 cases, a characteristic immunophenotype was identified (CD4+, CD13-, CD33+, CD65s+). AF-10 was involved in 5 of 6 evaluable cases, including 1 case without detectable CALM or MLL rearrangement. In 2 complex translocations, none of the three genes was rearranged. All cases had a remarkably poor prognosis, with a mean survival of 9.6 +/- 6.6 months. For the 7 AML cases that were uniformly treated according to the AMLCG86/92 protocols, disease-free and overall survival was significantly worse than for the overall study group (P = .03 and P = .01, respectively). We conclude that the t(10;11)(p13;q14) indicates CALM and MLL rearrangements in morphologically distinct subsets of acute leukemia and may be associated with a poor prognosis.

[Systemic therapy of low malignancy non-Hodgkin lymphomas]

Substantial progress has been achieved in eludicating the molecular mechanisms of malignant transformation, in establishing therapeutic standards and in evaluating innovative treatment strategies in patients with low grade Non-Hodgkin's Lymphoma. Correlation of genetic aberrations and immunologic marker profiles to histopathological entities and the clinical course has lead to a new transatlantic lymphoma classification. Today, application of 6-8 courses of moderately intensive induction polychemotherapy induces partial or complete remissions in 80% of patients in stage III or IV. Longterm maintenance therapy with interferon alpha significantly prolongs progression free survival. Current multicenter trials evaluate the curative potential of high-dose chemotherapy with autologous stem cell transplantation. Recently, several new approaches including new cytostatic drugs, immunotherapy with monoclonal antibodies and gene therapy with antisense oligonucleotides have been developed and have achieved remissions in pretreated patients. In the future, intensification of chemotherapy and the new treatment options may offer the potential for cure in patients with low malignant Non-Hodgkins Lymphoma.

Plasmacytosis in acute myeloid leukemia: two cases of plasmacytosis and increased IL-6 production in the AML blast cells

An increased plasma cell count in the bone marrow occurs in a subgroup of patients with acute myeloid leukemia (AML). The pathogenic mechanism for this plasmacytosis is unclear. In this report we describe two patients with AML and plasmacytosis who shared some features of their diseases. The morphological subtypes were AML M4 and M4eo; the leukemias were secondary to cytotoxic pretreatment, and complex cytogenetic changes were found in the leukemic cells of both patients. There was a marked increase in the number of bone marrow plasma cells in both cases and no monoclonal immunoglobulin was detectable. The IgH-CDR3 gene scan depicted a monoclonal IgH rearrangement in the bone marrow cells of one patient. Analysis of the cytokine production of the leukemic cells showed a high production of IL-6 of the leukemic blast cells in the in vitro cell culture and a high cytoplasmic IL-6 in the leukemic cells as revealed by immunocytology. We describe the clinical picture of a type of secondary AML with FAB M4 morphology associated with bone marrow plasmacytosis. We suggest that paracrine growth stimulation of plasma cells by paraneoplastic IL-6 production of the leukemic blast cells contributes to the plasmacytosis observed in patients with AML.

Intensive therapy for high-risk myelodysplastic syndromes and the biological significance of karyotype abnormalities

Therapy for myelodysplastic syndromes (MDS) has been less than effective when based on low-dose treatment or supportive measures only, including hematopoietic growth factors. Recently, based on the percentage of bone marrow blasts, the number of cytopenic cell lines and cytogenetics, clinical risk groups have been defined more precisely. Recent studies applying intensive acute myeloid leukemia (AML)-type therapy to high-risk MDS have produced remissions ranging from 45 to 79%. Advances in the understanding of the biology of MDS clearly point to cytogenetics rather than morphologic subtype as being of prognostic relevance. Hence, new treatments need to be developed for patients with unfavorable karyotypes and complex abnormalities in particular. These MDS subtypes are characterized by low spontaneous proliferative activity and low autocrine production of hematopoietic growth factors. The subtypes are, however, highly sensitive to external stimulation by granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF). New therapies could emerge from these findings, for example, priming high-risk MDS patients with hematopoietic growth factors in combination with intensive AML-type treatment. Recent studies suggest that incorporating high-dose AraC into an intensive drug combination could further improve the outcome of high-risk MDS.

Mantle-cell lymphomas have more widespread disease and a slower response to chemotherapy compared with follicle-center lymphomas: results of a prospective comparative analysis of the German Low-Grade Lymphoma Study Group

PURPOSE

To compare mantle-cell lymphomas (MCLs) and follicle-center lymphomas (FCLs) for their features of clinical presentation, response to chemotherapy, and prognosis on the basis of a prospective randomized clinical trial.

PATIENTS AND METHODS

Patients with MCL and FCL who entered onto the prospective randomized comparison of cyclophosphamide, vincristine, and prednisone (COP) versus prednimustine and mitoxantrone (PmM) followed by a second randomization for interferon (IFN) maintenance versus observation only.

RESULTS

One hundred sixty-five of 234 patients had FCL and 45 of 234 patients had MCL. With FCL, both sexes were equally affected (men, 47%); patients with MCL were predominantly men (78%; P < .0004) and had a higher median age (64 v 53 years; P < .0001). Patients with MCL also had more widespread disease, reflected by the proportion of patients with two or greater extranodal manifestations (43% v 21%; P < .005) and nine or greater involved nodal areas (64% v 45%; nonsignificant [NS]). Response to chemotherapy was significantly lower in patients with MCL (complete remission [CR] + partial remission [PR], 69% v 88%; P < .05) and occurred at a slower pace. Patients with MCL also had a shorter event-free interval (median, 8 v 24 months; P < .0001) and overall survival (median, 28 v 77 months; P < .0001). In both subtypes, however, patients with less than two residual lymphoma manifestations in remission experienced a relatively good prognosis with an estimated 5-year survival of greater than 60% for MCL and greater than 75% for FCL.

CONCLUSION

MCL and FCL differ substantially in their features of presentation, response to chemotherapy, and long-term prognosis. The extent of residual disease after completion of chemotherapy discriminates patients with different prognosis and may be used for the stratification of postremission strategies.

Early intensive and myeloablative adjuvant chemotherapy in women with high-risk breast cancer

BACKGROUND

Women with breast cancer and > 10 positive lymph nodes have an unfavorable prognosis. The optimal combination and intensity of adjuvant chemotherapy is uncertain. Between July 1994 and December 1996 we treated 19 patients with early intensive followed by high-dose chemotherapy and autologous peripheral blood stem cell transplantation.

PATIENTS AND METHODS

Patients were initially diagnosed with breast cancer and multiple positive lymph nodes. Induction chemotherapy consisted of two courses VP16, ifosphamide, cisplatin and epirubicin (VIPE) and one course of mitoxantrone, cyclophosphamide and thiotepa (MCT). Peripheral blood stem cells were mobilized after the first or second course of VIPE and retransfused two days after high dose chemotherapy.

RESULTS

Stem cells were successfully collected in all patients. Major toxicities (WHO grade III and IV) were neutropenia, thrombocytopenia, alopecia, nausea, infections and mucositis. Hematopoietic recovery occurred in all patients with a median of 10 days for leukocytes and 13 days for platelets. No patient died of therapy-induced complications. The median observation time is 24 months. Two patients have relapsed, one with locoregional disease. The projected rate of patients with disease-free survival after three years is 88%.

CONCLUSIONS

Early intensive and myeloablative chemotherapy followed by peripheral blood stem cell transplantation is a highly efficient and feasible protocol for high risk patients with breast cancer.

Elevated expression of S100P, CAPL and MAGE 3 in doxorubicin-resistant cell lines: comparison of mRNA differential display reverse transcription-polymerase chain reaction and subtractive suppressive hybridization for the analysis of differential gene expression

Subtractive suppressive hybridization (SSH) and mRNA differential display reverse transcription-polymerase chain reaction (DDRT-PCR) were compared for their ability to detect the expression of drug-resistance associated genes in a doxorubicin-resistant and -sensitive colon carcinoma cell line (LoVo H67P). The expression pattern of more than 9000 bands obtained by DDRT-PCR were identical in both cell lines by more than 95%. Of the remaining differentially expressed DDRT-PCR products, 21 cDNA fragments were further analyzed after cloning. A total of 210 clones were sequenced resulting in 40 different sequences of which only five were differentially expressed as revealed by Northern blot analysis. SSH, on the other hand, resulted in 30 different sequences of 37 clones analyzed. Thirteen of 30 sequences (43%) could be identified by databank analysis (excluding expressed sequence tags) in contrast to nine of 40 clones (23%) obtained by DDRT-PCR. Of the clones identified by SSH, 60% exhibited a differential expression comparing the doxorubicin-resistant and -sensitive cell line, respectively, as compared to only 13% of the DDRT-PCR derived clones. The application of SSH resulted in the identification of differentially expressed genes in three doxorubin-resistant cell lines (LoVo DxR, ARH D60 and KB-V1) as compared to the sensitive parental cell lines. A significant higher expression of S100P, a protein involved in calcium metabolism, as well as MAGE 3 (melanoma antigen gene) was found in the resistant cell lines using this methodology. The expression of CAPL, a second protein involved in calcium metabolism, was only moderately elevated in the doxorubicin-resistant cells. We found that subtractive suppressive hybridization proved to be a more rapid and reliable method for the detection of differentially expressed mRNAs in our system.