W. Gassmann

Double induction strategy including high dose cytarabine in combination with all- trans retinoic acid: effects in patients with newly diagnosed acute promyelocytic leukemia

A prospective multicenter study was performed to investigate the clinical and molecular results of intensified double induction therapy including high-dose cytarabine (ara-C) in combination with ATRA in newly diagnosed acute promyelocytic leukemia (APL), followed by consolidation and 3 years maintenance therapy. Fifty-one patients, diagnosed and monitored from December 1994 to June 1999, were evaluated. The median age was 43 (16–60) years. The morphologic diagnosis was M3 in 40 (78%) and M3v in 11 (22%) patients. In 15 (30%) patients the initial white blood cell counts were ⩾5 × 109/l. The cytogenetic or molecular proof of the translocation t(15;17) was a mandatory prerequisite for eligibility. The diagnosis was confirmed by karyotyping in 46 and by RT-PCR of the PML/RARα transcript in 45 cases. The rate of complete hematological remission was 92% and the early death rate 8%. Monitoring of minimal residual disease by RT-PCR of PML/RARα (sensitivity 10−4) showed negativity in 29 of 32 (91%) evaluable cases after induction, in 23 of 25 (92%) after consolidation, and in 27 of 30 (90%) during maintenance, after a median time of 2, 4 and of 18 months after diagnosis, respectively. After a median follow-up of 27 months, the estimated actuarial 2 years overall and event-free survival were both 88% (79, 97), and the 2 years relapse-free survival 96% (90, 100). The high antileukemic efficacy of this treatment strategy is demonstrated by a rapid and extensive reduction of the malignant clone and by a low relapse rate. The results suggest that the intensity of the induction chemotherapy combined with ATRA is one of the factors which may have a critical influence on the outcome of APL. A randomized trial should assess the value of an induction therapy including ATRA and high-dose ara-C in comparison to standard-dose ara-C.

Prognostic significance of additional chromosome abnormalities in adult patients with Philadelphia chromosome positive acute lymphoblastic leukaemia

The clinical and biological significance of additional chromosome aberrations was investigated in a large series of 66 adult patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia (ALL). Additional chromosome changes were observed in 71% of the cases. 9p abnormalities were identified in 26%, and monosomy 7 as well as hyperdiploid karyotypes >50 were both found in 17% of cases. 9p anomalies were characterized by a low complete remission (CR) rate (58%) and an extremely short median remission duration (MRD; 100 d). In patients with monosomy 7, the poor treatment outcome was confirmed (CR rate 55%; MRD 113 d). In contrast, all patients with hyperdiploid karyotypes >50 achieved CR, and the overall survival was superior to all other Ph‐positive ALL patients except those without additional chromosome aberrations. Exclusive rearrangement of the minor breakpoint cluster region of the BCR gene and lack of coexpression of myeloid‐associated antigens in cases with 9p anomalies as well as a high frequency of rearrangements of the major breakpoint cluster region of the BCR gene in patients with monosomy 7 (89%) further substantiated that additional chromosome aberrations may characterize distinct subgroups of Ph‐positive ALL. Moreover, the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph‐positive patients has become evident due to variant Ph translocations in 3%, and negative PCR assays in 4% of the cases.

Acute Megakaryoblastic Leukemia

In 1985 acute megakaryoblastic leukemia was included in the FAB classification system of hematological neoplasias with the designation of AML M7. It occurs in all age groups with two peaks in distribution. The one is in adults and the other in children 1 to 3 years of age especially in those with Downs syndrome. The diagnosis of AML M7 requires more than 30% of the nucleated bone marrow cells being megakaryoblasts. The more common types of AML MO-M6 have to be excluded by morphological and cytochemical analysis whereas immunology is needed to exclude ALL. The megakaryocytic nature of the leukemia has to be proven by ultrastructural demonstration of platelet peroxidase or by immunological demonstration of CD61, CD42, CD41 on the surface of the leukemic blasts. Megakaryocytic/megakaryoblastic leukemias show a wide morphologic spectrum. In some instance small cells dominate, clearly showing megakaryocytic differentiation with scant amounts of cytoplasm and with nuclei showing dense chromatin. On the other hand, there are cases with larger cells resembling ALL-L2 blasts with moderate amounts of rather basophilic cytoplasm which in some instances contain azurophilic granules. Cytoplasmic blebs and protrusions are the most prominent feature of many cases. The nuclei of these cells are round with more finely reticulated chromatin and with prominent nucleoli. The megakaryoblastic nature of these cells can be suggested by morphology. However, according to our experience there are cases of c-ALL with the very same morphologic picture. Consequently, immunologic phenotyping of these cases is necessary in any instance. Cytochemistry is of limited diagnostic value in megakaryoblastic leukemias. Usually it is used to exclude the more common types of leukemia.

Impact of comorbidities on overall survival in patients with chronic myeloid leukemia: results of the randomized CML-Study IV

We studied the influence of comorbidities on remission rate and overall survival (OS) in patients with chronic myeloid leukemia (CML). Participants of the CML Study IV, a randomized 5-arm trial designed to optimize imatinib therapy, were analyzed for comorbidities at diagnosis using the Charlson Comorbidity Index (CCI); 511 indexed comorbidities were reported in 1519 CML patients. Age was an additional risk factor in 863 patients. Resulting CCI scores were as follows: CCI 2, n = 589; CCI 3 or 4, n = 599; CCI 5 or 6, n = 229; and CCI ≥ 7, n = 102. No differences in cumulative incidences of accelerated phase, blast crisis, or remission rates were observed between patients in the different CCI groups. Higher CCI was significantly associated with lower OS probabilities. The 8-year OS probabilities were 93.6%, 89.4%, 77.6%, and 46.4% for patients with CCI 2, 3 to 4, 5 to 6, and ≥7, respectively. In multivariate analysis, CCI was the most powerful predictor of OS, which was still valid after removal of its age-related components. Comorbidities have no impact on treatment success but do have a negative effect on OS, indicating that survival of patients with CML is determined more by comorbidities than by CML itself. OS may therefore be inappropriate as an outcome measure for specific CML treatments. The trial was registered at www.clinicaltrials.gov as #NCT00055874.

Allogeneic MHC-mismatched activated natural killer cells administered after bone marrow transplantation provide a strong graft-versus-leukaemia effect in mice.

Allogeneic lymphocytes administered with an unmanipulated bone marrow transplant provide a strong antileukaemic effect, the so‐called graft‐versus‐leukaemia (GVL) effect. On the other hand, T‐cell‐mediated graft‐versus‐host‐disease (GVHD) observed after transplantation of unmanipulated BM graft causes substantial morbidity and mortality. The aim of the present study was to determine the antileukaemic potential of enriched IL‐2 activated NK cells administered 2 h after BMT. Balb/c (H‐2d) mice were given a dose of A20 (H‐2d, B‐cell leukaemia) cells 2 d prior to lethal total body irradiation (TBI) and transplantation of either syngeneic or allogeneic anti‐Thy1.2 (CD90) depleted bone marrow cells. Either syngeneic (Balb/c, H‐2d) or allogeneic (C57BL/6, H‐2b) enriched and IL‐2 (200 U/ml for 24 h) activated NK cells were given 2 h after BMT. Injection of A20 leukaemia into normal Balb/c recipients led to death after a median of 14 d. A lethal dose of TBI followed by either syngeneic or allogeneic Thy1.2‐depleted BMT resulted in a modest antileukaemic effect. The adoptive transfer of syngeneic enriched and IL‐2 preincubated NK cells given at time of BMT exerted a significantly better GVL effect. However, the infusion of allogeneic enriched NK cells resulted in a stronger GVL effect. These results clearly demonstrate that allogeneic NK cells are superior to syngeneic NK cells in their potential to eradicate residual leukaemia cells after BMT without mediating clinical overt GVHD. This experimental setting may offer a strategy for treatment of haematological malignancies in a phase of minimal residual disease.

Which compartments are involved in Philadelphia-chromosome positive chronic myeloid leukaemia? An answer at the single cell level by combining May-Grünwald-Giemsa staining and fluorescence in situ hybridization techniques

Chronic myeloid leukaemia (CML) is believed to represent a stem cell disorder involving all three cell lineages. The typical chromosomal aberration, the Philadelphia chromosome, is the translocation (9;22)(q34;q11). Several studies with cytogenetics, fluorescence in situ hybridization (FISH), or polymerase chain reaction have investigated the presence of the t(9;22) in different cell compartments. However, questions still remain. In six cases of CML we combined the standard May‐Grünwald‐Giemsa staining with FISH at the single‐cell level and were able to demonstrate that not only all maturation stages of granulopoiesis, erythropoiesis, and megakaryocytes, but also plasma cells, eosinophils, basophils and monocytes carried the Philadelphia chromosome in 53–98% of samples. Using immunological identification of single cells we were able to demonstrate that the t(9;22) is detectable in 34% of CD3‐positive T lymphocytes, in 32% of CD19‐positive B lymphocytes, and in 82% of CD34‐positive precursor cells. The results give new insight into the biology of CML and may have implications for future therapeutic strategies.

Gaft-versus-leukemia activity after bone marrow transplantation does not require graft-versus-host disease

SummaryClinical data have suggested that graft-versus-host disease (GVHD) plays a crucial role in the antileukemic effects of bone marrow grafts. We investigated (a) whether bone marrow cells unable to induce GVHD can effect graft-versus-leukemia (GVL) activity and (b) whether such antileukemic capacity depends on the presence of T lymphocytes in the graft. Balb/c mice were inoculated with A 20 cells, a B-cell lymphoma/leukemia of Balb/c origin. Four weeks after tumor inoculation the animals were lethally irradiated and received a bone marrow graft. Cells from (Balb/c × C57) F1 or (C3H × Balb/c) F1 hybrids were transplanted into parental-strain Balb/c mice. Since lymphocytes from F1 hybrids are unable to cause graft-versus-host reactivity against a parental-strain animal, we used this experimental setting to explore GVL effects in a GVHD-free system. In vitro incubation with monoclonal anti-Thy-1.2 antibody plus complement was used to eliminate Thy-1+ cells. After syngeneic transplantation, the death rate due to leukemia remained unchanged (91%) compared with that among untreated animals (86%). Following transplantation of F1 marrow cells of either (C57 × Balb/c) F1 or (C3 H × Balb/c) F1 origin, death rates of 40% and 50% were observed; these were significantly lower. Depletion of Thy 1+ cells from bone marrow graft caused only a slight increase in the leukemic death rate after transplantation of bone marrow of (C57 × Balb/c) F1 hybrid origin (50%), but a high leukemic death rate was seen after transplantation of (C3H × Balb/c) F1 bone marrow (100%). Additional experiments with fully allogeneic, T-cell-depleted C57 bone marrow transplantation suggest an antileukemic effect that is comparable to that seen after transplantation of unmanipulated F1 bone marrow. Taken together, our results indicate that GVL activity can be dissociated from graft-versus-host reaction.

High rate of chromosome abnormalities detected by fluorescence in situ hybridization using BCR and ABL probes in adult acute lymphoblastic leukemia

The value of dual-color fluorescence in situ hybridization (FISH) with BCR and ABL probes for the detection of the Philadelphia (Ph) translocation and of other alterations involving ABL and/or BCR was evaluated in adult acute lymphoblastic leukemia (ALL). One hundred and four patients were studied prospectively using interphase nuclei FISH, chromosome analysis (CA), and PCR assays for the chimeric BRC/ABL transcript. FISH detected a Ph translocation in 24 cases (23.1%), as was confirmed by CA and/or PCR. FISH revealed a false positive diagnosis of a Ph translocation in four cases (5% false positive rate). Among 54 cases with combined FISH, CA and PCR assays, FISH failed to establish a correct diagnosis in 3.7%, PCR in 5.6%, and CA in 7.4%. The combination of two screening methods led to discrepant results in 9.3% (FISH + PCR), 11.1% (FISH + CA), or 13% (CA + PCR) of the cases. In seven of 80 (8.8%) Ph-negative patients, gain of BCR and/or ABL was identified. Overall, FISH detected alterations of the BCR and/or ABL genes with an incidence of 29.8% of the current study. Due to the possibility of false positive diagnosis of a Ph translocation using dual-color FISH the combination with chromosome and/or RT-PCR analyses is recommended in adult ALL patients.

Staging systems for multiple myeloma: a comparison.

Summary In 152 patients with multiple myeloma who had been treated with cytostatic agents the prognostic value of seven staging systems was evaluated: (1) Carbone et al (1967); (2) Acute Leukemia Group B (ALGB) and Eastern Cooperative Oncology Group (ECOG) (Costa et al, 1973); (3) Southeastern Cancer Study Group (SECSG) (1975); (4) Durie & Salmon (1975); (5) Alexanian et al (1975); (6) Merlini et al (1980); (7) British Medical Research Council (1980).

Secondary acute leukaemias with 11q23 rearrangement : clinical, cytogenetic, FISH and FICTION studies

Three patients with secondary acute leukaemia after treatment with topoisomerase II inhibitor agents are described. Two patients had acute myeloid leukaemia (AML), FAB M5a, one had pro‐B‐acute lymphoblastic leukaemia (ALL). The interval between initiation of chemotherapy and the onset of secondary acute leukaemia was 19–20 months. 11q23 rearrangements were detected in all cases. They were due to translocations t(11;19) (q23;p13.3), t(11;16)(q23;p13) and t(4;11)(q21;q23), respectively. Fluorescence in situ hybridization (FISH) with Yeast Artificial Chromosome (YAC) probe 13HH4 spanning the ALL‐1 gene on 11q23 confirmed that in each case the ALL‐1 gene had been disrupted by the translocations. The study underlined the relationship between the development of secondary acute leukaemias with 11q23 rearrangement and previous chemotherapy with topoisomerase II inhibitor agents. So far, however, only six adult patients with secondary ALL with t(4;11) after treatment with topoisomerase II inhibitor agents have been reported. ALL with t(4;11) mostly occurs in infants or young children. Our patient received epirubicin continuously for >19 months. This indicates that both myeloid and lymphoid leukaemias with involvement of the ALL‐1 gene can be induced by exogenous agents, especially topoisomerase II inhibitors. Thus they may have a common biological background. This hypothesis was substantiated by means of combined immunophenotyping and FISH (FICTION). In the case of AML M5a with t(11;19), the tumour cells with ALL‐1 rearrangement expressed CD34. Moreover, the pro‐B‐ALL with t(4;11) was CD34 positive. These findings suggest that the cell of origin of secondary AML and ALL with 11q23 rearrangement is an immature haemopoietic progenitor cell.