Consolidation therapy for adult acute myeloid leukemia: a systematic analysis according to evidence based medicine.

Post-remission therapy in acute myeloid leukemia (AML) remains problematic. It has been demonstrated that younger patients can maintain longer complete remissions (CR) with aggressive post-remission therapies after induction treatment: allogeneic (allo), autologous (auto) stem cell transplantation (SCT), or intensive chemotherapy (ICC). The purpose of our study was to identify the most important randomized and controlled studies comparing these three therapeutic options, in order to draw conclusions and possible suggestions for post-remission therapy of AML, according to the evidence based medicine (EBM) rules. We performed an exhaustive analysis of the literature, searching either in electronic databases or among the references of the identified articles (hand searching). We searched the MEDLINE computer database for reports from 1985 through January 2005 and selected for analysis the clinical trials conducted over adults affected by newly diagnosed AML aged less than 65 years. The study design had to satisfy strict methodological criteria and must consider global mortality and/or disease free survival as primary outcomes. Overall we found 7750 papers; by using the limits "clinical trial" as publication type, "all adults 19+ years", we were able to select 344 papers. Among these, a further selection was made, based on two main clinical queries: 1) is auto-SCT superior to ICC/no other therapy in improving DFS and/or OS in adult AML patients in first CR? 2) is allo-SCT superior to auto-SCT/other therapeutic options in improving DFS and/or OS in adult AML patients in first CR? Concerning the first query, a possible advantage of auto-SCT over ICC was not clearly supported by data from clinical trials; there is no evidence that auto-SCT is superior in terms of OS to chemotherapy. Nevertheless, the reported TRM has been significantly reduced within the past years. Thus, the percentage of patients suitable for auto-SCT in CR has increased. Moreover, the scarce data concerning the comparison between auto-SCT and chemotherapy in different subsets of patients are unable to suggest a differentiated approach in patients with high-risk, standard-risk or low-risk AML. Data from the literature show that patients with unfavorable risk disease are more often addressed to allo-SCT and patients with low-risk disease receive more often intensive consolidation chemotherapy. Concerning the second query, interpretation of data from the main prospective studies about the role of allo-SCT in previously untreated AML is not easy. The first problem is the lack of real randomized clinical trials; in fact, according to the reported studies, AML patients generally receive allo-SCT on the basis of donor availability (the so called "genetic randomization"). The second problem is the frequent absence of intention to treat analysis. Despite methodological limitations, it was possible to compare allo-SCT with auto-SCT on a donor versus no-donor analysis and within risk groups. No overall benefit of allo-grafting on survival was demonstrated by any trial. In conclusion, the EBM approach highlighted the limitations observed in the published studies concerning consolidation therapy in AML; some suggestions, emerging from non-randomized, as well as randomized studies, are adequate, but not conclusive. This point, coupled with the intrinsic complexity to study AML biological heterogeneity, is probably a major obstacle to draw conclusive evidences for consolidation therapy in AML. These observations should plan to address new randomized studies on AML therapy; however, due to the emergence of genetic subgroups and new drugs targeting specific abnormalities, these trials should probably be designed directly focusing on the single entities. In this way, the cure of AML could eventually become the cure of each specific AML subset with its peculiar biological, molecular and prognostic features.

Feasibility of peripheral blood stem cell rescue as intensification in elderly patients with acute myelocytic leukaemia: a pilot study from the Gimema Group. Gruppo Italiano Malattie Ematologiche Maligne Dell'Adulto.

Elderly patients with untreated acute myeloid leukaemia (AML, n = 47) tested the feasibility of out-patient consolidation therapy and post-consolidation treatment (for patients aged < 71 years) with autologous peripheral blood stem cell transplantation (APBSCT). Overall, 13 patients out of 24 (51%) who achieved complete remission (CR) were eligible for further treatment after consolidation. Five patients were primed with granulocyte colony stimulating factor (G-CSF); a suitable number of CD34+ cells were harvested in three patients and were actually autotransplanted. The toxicity of APBSCT was negligible. Psychosocial problems impaired treatment of some patients on an out-patient basis. Resistant disease, toxicity and logistic problems reduced the number of patients to whom this procedure could actually be applied.

Haploidentical bone marrow transplantation from mother to child with advanced leukemia.

Use of the mother as mismatched marrow donor was assessed in 19 children with advanced leukemia. Patients were homogeneous for HLA incompatibility, age, donor, and conditioning regimen, and stage of disease. All received busulfan and cytoxan, combined with unmodified donor marrow, ALG given before and after transplant, and short MTX and cyclosporine as GVHD prophylaxis. Survival, LFS, and relapse respectively were 26, 26, and 33%. Incidence of overall and severe acute GVHD was 58 and 32%, respectively. Four patients had failure of engraftment, and two of these are alive with autologous reconstitution in complete remission. Probability of rejection was 21%. Results of haploidentical transplants were compared with those of children with advanced leukemia treated at the same institution, who received marrow from HLA-identical siblings. The probability of long-term leukemia-free survival was similar in the two groups. We thus propose using the mother as an alternative marrow donor in children with advanced leukemia.

Limiting dilution analysis of IL-2 producing cells: I. Studies of normal human peripheral blood.

BACKGROUND: After marrow transplantation, the interaction of helper T lymphocytes from the donor with the patient alloantigens leads to cellular activation and release of IL-2 as initial events of the graft versus host reaction. A method for assessing the size of the pool containing allospecific helper T cells capable of producing IL-2 could be applied in the selection of better donors for marrow transplantation. MATERIAL AND METHODS: PBMC are added to replicate sets of wells each containing various amounts of EBV-LCL cells and PHA. After culture for some days the supernatant is removed from each well and added to IL-2 dependent CTLL-2 line. The proliferation of the CTLL-2 line is assessed by pulse labeling with 3H-thimidine. The precursor frequency of cell capable of producing IL-2 per ml/blood is estimated from the minimum X2 regression of the function of non-responding wells plotted as logarithmic function of the number of PBMC added per well. RESULTS: Approximately 30-40% of PBMC are found to produce IL-2 under the following conditions in culture: the optimal PHA concentration is 1.25 micrograms/ml, the optimal number of stimulator EBV-LCL cells is 1 x 10(3) and 3 days of culture are required. CONCLUSION: Here we report a rapid and quantitative technique of limiting dilution analysis that can estimate the frequency of peripheral blood mononuclear cells capable of secreting interleukin-2 following interaction with specific alloantigen.

[An apparently primary lymphoma of the testicle]. / Linfoma apparentemente primitivo del testicolo.

A case of apparently primary non-Hodgkin's lymphoma of the testis is described. The patient, in stage IVE at the diagnosis, was treated with left orchiectomy and chemotherapy (MACOP-B). The abdominal CT scan showed a retroperitoneal lymph node involvement with infiltration of the right kidney and liver. The patient died 6 months after onset of the disease due to its progressive course.

Limiting dilution analysis for detection of residual leukemic cells after bone marrow combined decontamination with mafosfamide followed by merocyanine-540-mediated photosensitization.

Human acute myelogenous or lymphoblastic leukemia cells of the K-562 and CCRF-SB lines were mixed with an excess of normal human bone marrow cells to simulate a leukemia remission marrow. The cell mixtures were then incubated in vitro with mafosfamide (AZ) followed by the photoreactive dye merocyanine-540 (MC). Treated cells (1 x 10(4] were seeded in microwell plates, and increasing numbers of the line used to contaminate the normal marrow were added. Treatment with AZ alone produced total elimination (i.e., 6 logs) of CCRF-SB cells, while addition of merocyanine-540 increased the cloning efficiency from 22% to 24.4%. After treatment of the K-562-contaminated cell mixtures with AZ, nearly 1.6 logs of K-562 acute myelogenous blasts were still present, whereas AZ purging followed by MC-mediated photosensitization resulted in 100% elimination of clonogenic cells. Moreover, the combined treatment caused an increase of the cloning efficiency from 37.3% to 62%, clearly indicating that cleansing by the two agents combined was more effective than treatment with one agent alone.

Malignant melanoma of the glans penis in a chronic myeloid leukemia patient after busulfan therapy.

There are many case reports of secondary neoplasms occurring after treatment with alkylating agents. A case of malignant melanoma of the glans penis in a chronic myeloid leukemia (CML) Ph'-positive patient after 13 years on busulfan treatment is described. Since neither impairment of immune status nor increased incidence of secondary neoplasm have hitherto been reported in CML, the suggestion that busulfan has a carcinogenetic effect is discussed.

Limiting-dilution analysis for the determination of leukemic cell frequencies after bone marrow decontamination with mafosfamide or merocyanine 540.

To stimulate a leukemia remission marrow, cell suspensions of normal human bone marrow were mixed with human acute lymphoblastic or myelogenous leukemic cells of the CCRF-SF, Nalm-6, and K-562 lines. The cell mixtures were incubated in vitro with mafosfamide (AZ) or with the photoreactive dye merocyanine 540 (MC-540). A quantity of 10(4) cells of the treated suspensions was dispensed into microculture plates, and graded cell numbers of the line used to contaminate the normal marrow were added. Limiting-dilution analysis was used to estimate the frequency of leukemia cells persisting after treatment with the decontaminating agents. Treatment with AZ or MC-540 produced a total elimination (ie, 6 logs or 5.3 logs respectively) of B cell acute leukemia cells (CCRF-SB), whereas nearly 1.7 logs and 2 logs of K-562 acute myelogenous blasts were still present in the cell mixtures after treatment with MC-540 and AZ, respectively. Treatment of the Nalm-6-contaminated cell mixtures with AZ resulted in 100% elimination of clonogenic cells, whereas nearly 80% decontamination was obtained with MC-540. Our results suggest that treatment with AZ could be an effective method of eliminating clonogenic tumor cells from human bone marrow. MC-540, shown by previous studies to spare sufficient pluripotential stem cells to ensure hemopoietic reconstitution in the murine model and in clinical application, has comparable effects and merits trials for possible clinical use in autologous bone marrow transplantation.

Effect of two cyclophosphamide derivatives on hemopoietic progenitor cells and pluripotential stem cells.

The studies described herein were undertaken to help define the effects of certain cyclophosphamide derivatives that have been used for selective removal of leukemic cells from marrow samples used for autologous transplantation. We have tested the effect of 4-HC and another cyclophosphamide congener, ASTA-Z 7557, on pluripotent stem cells (CFU-S) and committed progenitor cells (CFU-GM) in mice. The CFU-S were evaluated by the spleen colony assay at eight days and 12 days after transplant. The eight-day colonies are transient in nature, rapidly growing, mainly erythroid, and lack pluripotential precursors. The 12-day colonies are believed to provide a measure of hemopoietic stem cells as they slowly grow and do contain primitive precursors. Our data show that at the maximum dose levels tested, both drugs caused a 100% loss of CFU-GM and about 80%-95% inhibition of early transient CFU-S. In contrast, about 70% of the pluripotent 12-day CFU-S were spared. These data appear to explain the hemopoietic recovery seen in man after transplantation with marrow cells treated with 4-HC despite their relative absence of hemopoietic progenitor cells.