Gene Expression Differences between Enriched Normal and Chronic Myelogenous Leukemia Quiescent Stem/Progenitor Cells and Correlations with Biological Abnormalities.

In comparing gene expression of normal and CML CD34+ quiescent (G0) cell, 292 genes were downregulated and 192 genes upregulated in the CML/G0 Cells. The differentially expressed genes were grouped according to their reported functions, and correlations were sought with biological differences previously observed between the same groups. The most relevant findings include the following. (i) CML G0 cells are in a more advanced stage of development and more poised to proliferate than normal G0 cells. (ii) When CML G0 cells are stimulated to proliferate, they differentiate and mature more rapidly than normal counterpart. (iii) Whereas normal G0 cells form only granulocyte/monocyte colonies when stimulated by cytokines, CML G0 cells form a combination of the above and erythroid clusters and colonies. (iv) Prominin-1 is the gene most downregulated in CML G0 cells, and this appears to be associated with the spontaneous formation of erythroid colonies by CML progenitors without EPO.

New understanding of the pathogenesis of CML: a prototype of early neoplasia.

The 9;22 chromosomal translocation characteristic of CML results in a fused bcr/abl gene and an abnormal fusion protein, p210bcr/abl. Relative to normal c-abl, p210bc1/abl has elevated tyrosine kinase activity that is essential for its transforming activity. We recently reported a prominent 62 kDa GAP-associated P-tyr protein and five additional consistent but less prominent P-tyr proteins as well as five more minor P-tyr proteins that are constitutively tyrosine phosphorylated in primary primitive lineage negative (lin-) chronic phase CML blasts but not in comparable primary lin- normal blasts. The GAP-associated p62 protein has now been purified, sequenced and its gene has been cloned; it is a previously unidentified protein and is currently being characterized. In analyzing P-tyr proteins in primary lin- normal blasts in response to various hematopoietic cytokines, we found a striking similarity in the tyrosine phosphorylation of four major and three minor proteins after stimulation with c-kit ligand (KL) and the P-tyr proteins that are constitutively phosphorylated in primary primitive lin- chronic phase CML blasts. Other cytokines tested (ie GM-CSF, G-CSF, IL-3, FLT3 ligand, TPO, EPO) were much less active or stimulated phosphorylation of other proteins. KL/c-kit and bcr/abl have some similar activities including enhancing survival and expansion of hematopoietic progenitor cells, probably acting primarily on early progenitors at the time of lineage commitment rather than on self-renewing stem cells. Activation of growth factor receptors promote a cascade of protein phosphorylations that can ultimately result in a wide range of cellular responses. Sustained activation of discrete signaling pathways in some types of cells results in differentiation, whereas transient activation instead causes a proliferative response; in other cell types, the converse is true. It may be postulated that stem cells and primitive progenitors are at a particularly susceptible stage of development that renders them especially responsive to sustained bcr/abl-induced phorphorylation of a number of signaling proteins that are components of critical regulatory pathways, including c-kit. The affected pathways control and coordinate multiple diverse cell processes including proliferation, differentiation, maturation and apoptosis, processes that are normally tightly regulated and integrated. Perturbation of these key pathways in primitive progenitors would be expected to seriously disrupt orderly hematopoiesis and could also explain the multiple subtle pleiotropic biological abnormalities characteristically observed in later maturing CML compartments that we have collectively designated 'discordant maturation'. The true situation is undoubtedly very complex and involves interaction of multiple cytokines and signaling pathways that we are now trying to define. Constitutive downstream activation of critical pathways in susceptible early progenitors that normally require KL or other factors for activation could explain most if not all features of the disease.

Long-term survivors in chronic granulocytic leukaemia: a study by the International CGL Prognosis Study Group. Italian Cooperative CML Study Group.

The purpose of the present work were to identify the initial characteristics associated with long-term survival in chronic granulocytic leukaemia (CGL) and to analyse the accuracy of prognostic models in identifying long-term survivors. 813 Philadelphia (Ph) chromosome-positive, nonblastic CGL patients from six American and European institutions, the majority treated conventionally, with a minimum follow-up > 10 years, were studied. Stepwise logistic regression was performed to ascertain the association between the initial clinicohaematological variables and survival > or = 8 years, and a prognostic index was derived. The usefulness of both Sokal's and the new prognostic index to identify long-term survivors was assessed by calculating their positive and negative predictive accuracies, sensitivity and specificity. Median survival of the series was 45 months (range 1-255), with 784 patients (96.4%) having died and 109 (13.4%) surviving 8 years or longer. Younger age, smaller spleen, platelets < or = 600 x 10(9)/l, and lower blood blast percentage were associated with survival > or = 8 years; platelets < or = 600 x 10(9)/l and lower blood blast percentage were the predictive factors in patients 50 years old or younger. Two-thirds of long survivors belonged to Sokal's low-risk group, but the positive predictive accuracy and specificity for prolonged survival of Sokal's index were very low. This was also the case for the new predictive index.(ABSTRACT TRUNCATED AT 250 WORDS)

Combination of hematopoietic growth factors containing IL-3 induce acute myeloid leukemia cell sensitization to cycle specific and cycle non-specific drugs.

Laboratory studies have suggested that hematopoietic growth factors (GF), combined with cytosine-arabinoside (Ara-C) can enhance cytotoxic effects of this agent against acute myeloid leukemia (AML) cells. While clinical trials based on this growth factor/chemotherapy combination (GF/CT) are progressing with discordant results, further information regarding the underlying mechanisms have been reported supporting this rationale and requiring additional investigation. To assess the role of cytokinetic changes in the GF/CT strategy and to evaluate if chemotherapeutic agents regimens other than Ara-C, when combined with GF, can enhance their cytotoxic effects, we have primed AML blasts with two cytokine combinations and then exposed these cells to the S-phase specific agent Ara-C as well as to the phase non-specific drug daunorubicin (DNR) and to the alkylating agent 4-hydroperoxycyclophosphamide (4-HC). The two cytokine combinations used for priming AML blasts were: (i) interleukin-3 (IL-3) + granulocyte-macrophage colony-stimulating factor (GM-CSF) + granulocyte colony-stimulating factor (G-CSF); and (ii) GM + G-CSF. Cytokinetic analysis in ten AML samples and clonogenic growth of leukemic colonies (CFU-L) in methylcellulose were used to detect proliferative and cytotoxic effects on AML samples. We report that in AML clonogenic cell growth can be stimulated by cytokines in 50% of the samples (4/8), and that Ara-C sensitization clearly occurs in two out of these four samples. Among the different cytokine combinations tested, the one containing IL-3 was the most effective through a cytokinetic mechanism consistent with recruitment (averaged G0 decrease p = 0.04; S-phase increase p = 0.005). Furthermore we observed increased cytotoxicity also to the phase non-specific drugs DNR and 4-HC, which may be mediated by other mechanisms recently described. We conclude that GF/CT combinations may also be beneficial in regimens containing drugs other than Ara-C, used for AML treatment, including bone marrow transplantation conditioning regimens.

Adjuvant cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy after radiation therapy in stage I low-grade and intermediate-grade non-Hodgkin lymphoma. Results of a prospective randomized study.

BACKGROUND: In a prospective randomized manner, this study evaluated the effect of adjuvant chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone; CHOP) in patients with Stage I non-Hodgkin lymphoma (NHL) who have achieved a complete response (CR) after radiation therapy (RT). METHODS: Forty-four patients with clinical or pathologic Stage I intermediate-grade or low-grade NHL were randomized to receive regional RT alone (median dose, 40 Gy) or regional RT followed by six cycles of CHOP chemotherapy. There were no differences in clinical and pathologic characteristics between the two treatment groups. RESULTS: The median follow-up was 7 years (range, 2-10 years). The actuarial relapse-free survival (RFS) rate for the RT plus CHOP group at 7 years was 83% compared with 47% (P < 0.03) for the RT-alone group. The overall survival (OS) for the two groups was 88% and 66%, respectively (P = 0.2). In patients with intermediate-grade NHL, the 7-year actuarial RFS for RT and CHOP was 86% compared with 20% for RT alone (P = 0.004). The corresponding actuarial survival rates were 92% and 47%, respectively (P = 0.08). In patients with low-grade histologic findings, the addition of adjuvant CHOP did not improve RFS (P = 0.6) or OS. All relapses in this study were at sites remote from the initially involved areas, and in 5 of 11 patients (45%), there were recurrences 5 years or longer after initial treatment. CONCLUSIONS: This study showed that adjuvant CHOP chemotherapy significantly improves RFS in patients with Stage I intermediate-grade NHL who achieve a CR after regional-field RT. The chemotherapeutic regimen favorably affected their probability of survival.

TGF-beta 3 protects normal human hematopoietic progenitor cells treated with 4-hydroperoxycyclophosphamide in vitro.

In this study we have investigated the ability of transforming growth factor-beta 3 (TGF-beta 3, 1000 pM) to protect hematopoietic bone marrow (BM) progenitor cells from the cytotoxic activity of 4-hydroperoxycyclophosphamide (4-HC, 100 microM) in vitro. Hematopoietic progenitors were purified by negative depletion of accessory and maturing cells or enriched by positive (CD 34+ cells) selection. For comparison the same treatment was tested on three different lymphoid cell lines CEM, SK-DHL-2, and LY-16. The experimental protocol was designed to mimic ex vivo purging conditions. Therefore, tumor cells and enriched hematopoietic precursors were mixed with irradiated BM cells. Our results demonstrated that preincubation of enriched progenitor cells with TGF-beta 3 for up to 72 h followed by 4-HC treatment resulted in an increased survival of colonies derived from granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) colony-forming cells, whereas a substantially lower number of colonies was observed in the control group. Similar results were observed when BM cells were first treated with 4-HC followed by TGF-beta 3 incubation for 24 or 48 h. In contrast, TGF-beta 3 provided no protection to the 4-HC cytotoxicity toward the lymphoma and leukemia cell lines. Three to four log of tumor cell killing was induced by 4-HC in the presence or absence of preincubation with TGF-beta 3. These data suggest that TGF-beta 3 is able to protect normal BM progenitors from the cytotoxic activity of an alkylating agent (4-HC) in vitro, whereas it does not offer any protection to lymphoma cell lines. These findings will have important implications for developing better purging conditions for autologous GM transplantation.

Phorbol ester-induced hairy cell features on chronic lymphocytic leukemia cells in vitro.

Leukemic cells from eight patients with chronic lymphocytic leukemia were isolated and cultured in the continuous presence of 12-O-tetradecanoylphorbol 13-acetate (TPA) at a concentration of 1.6 x 10(-9) M for 4-10 days. Aliquots of cells were then analyzed at intervals of 24-72 hr for changes in morphology, acid phosphatase staining (AP), and expression of two hairy cell-associated surface antigens, HCL1 (CD22, Leu 14) and HCL3 (CD11c, Leu M5). All cases studied showed typical B-CLL phenotype, and only a small proportion of cells expressed CD22 and CD11c (mean 7% and 4.9%, respectively). TPA treatment induced the coexpression of CD22 (mean 49%) and CD11c (mean 48%) and tartrate-resistant acid phosphatase in seven of eight cases. Morphologically, cells in TPA cultures expressed hairy cell features that were evident in light and electron microscopic studies. Collectively these changes indicate that TPA can induce hairy cell features on CLL cells in vitro, suggesting the later maturational stage of HCL compared with CLL.

A phase II pilot trial of high-dose hydroxyurea in chronic myelogenous leukemia.

Suppression or eradication of the Philadelphia (Ph1) chromosome has been a major goal in the therapy of chronic myelogenous leukemia (CML). Variable levels of Ph1 chromosome negativity have been achieved using interferon-alfa, busulfan, combination chemotherapy, and allogeneic bone marrow transplantation. This study evaluated the effect of achieving a predetermined level of myelosuppression using hydroxyurea on bone marrow cytogenetics in CML. Fourteen patients with chronic phase CML received 25 cycles of therapy. Fourteen of the 25 cycles were associated with cytogenetic responses consisting of 25% or more Ph1 negative metaphases (range, 25% to 100%). Nine of the responses consisted of 50% or greater Ph1 negative metaphases. Toxicity was exclusively due to consequences of myelosuppression, including febrile neutropenia and thrombocytopenia. In chronic phase CML, hydroxyurea induces cytogenetic responses with tolerable toxicity and is an attractive agent for further study as a component of treatment strategies aimed at eradicating the Ph1 + population in CML.

Proliferation of human hematopoietic progenitors in long-term bone marrow cultures in gas-permeable plastic bags is enhanced by colony-stimulating factors.

We compared the recovery of human hematopoietic progenitors in long-term bone marrow culture (LTBMC) initiated in tissue culture (TC) flasks to that in "Lifecell" bags, which are gas-permeable plastic bags in which feeder-layer cells cannot adhere. Our results showed that granulocyte-macrophage colony-forming unit (CFU-GM) and erythroid burst-forming unit (BFU-E) cumulative recovery in cultures from normal donor marrow, expressed as a percent of the initial inoculum, was not statistically different in the two culture systems up to week 8, when the cultures were terminated: 31.5 +/- 19 (flask) vs 30 +/- 14 (bag) and 15.5 +/- 12 (flask) vs 11.5 +/- 8 (bag), respectively. The effects of weekly addition of recombinant human (r-hu)-interleukin 1 (IL1) and r-hu-interleukin 3 (IL3) were then studied, alone and combined, at two different concentrations. Addition of IL1, either alone or combined with IL3, in LTBMC established in flasks induced an increase of hematopoietic progenitors for the first week, but BFU-E and CFU-GM were no longer detectable at weeks 4 and 6, respectively. Analysis of adherent layer cells showed a decreased cellularity, no adipogenesis, and early disappearance of bone marrow (BM) progenitors, whereas the cycling rate of myeloid precursors, by cytosine arabinoside (Ara-C) suicide assay, was similar to that of untreated cultures. Conversely, IL3 alone (5 ng/ml) resulted in 3.6- and 5.4-fold peak increases for CFU-GM and BFU-E, respectively, at week 1 (adherent plus nonadherent cells), and the recovery of BM cells was still higher than that of control flasks at week 8. By comparison, stimulation with colony-stimulating factors (CSFs) of BM cells grown in bags never affected the longevity of the culture. Addition of IL3 (5 ng/ml) induced a higher recovery of total cells, CFU-GM (range: 1.6- to 15-fold peak increase during the culture), and BFU-E (1.2- to 3-fold) compared to the untreated controls. Bags treated with IL1 alone demonstrated only transient beneficial effects, and the number of hematopoietic precursors fell below the level of control bags during the culture. IL1 and IL3 induced 1.8- and 5.3-fold peak increases in BFU-E and CFU-GM at weeks 1 and 4, respectively. Simultaneous flow cytometric analysis of CD34+/CD33+ cells and DNA content showed increased numbers and proliferation of the committed BM progenitors when CSFs were added to the bag.(ABSTRACT TRUNCATED AT 400 WORDS)

Duration of the preclinical phase of chronic myelogenous leukemia: a case report.

The molecular events that allow for clonal expansion of the malignant population in chronic myelogenous leukemia (CML) are poorly understood. Recent experiments in transgenic mice suggest a close temporal relationship between expression of the aberrant protein and manifestation of a hematologic neoplasm that resembles CML; tracing the same phenomenon in humans has not been possible. We studied a patient who underwent autologous bone marrow harvest after completion of chemotherapy and radiation therapy for advanced stage Hodgkin's disease. At the time of harvest his peripheral blood counts and bone marrow were morphologically normal. Sixteen months later he developed the clinical manifestations of CML. Detailed molecular evaluation of the harvested marrow showed that a small number of cells contained the Philadelphia chromosome. The time interval required for expansion of the malignant clone, as suggested by this particular patient, was at least 16 months although it is recognized that this figure may be variable.

Impact of adjuvant radiation on the patterns and rate of relapse in advanced-stage Hodgkin's disease treated with alternating chemotherapy combinations.

The role of adjuvant radiation therapy (RT) in the management of advanced-stage Hodgkin's disease (HD) was analyzed in 222 patients who attained a complete remission (CR) with alternating chemotherapy combinations. Mechlorethamine, vincristine, procarbazine, and prednisone/doxorubicin, bleomycin, vinblastine, and dacarbazine (MOPP/ABVD) or MOPP/ABV alternating with the lomustine, melphalan, and vindesine combination (MOPP/ABV/CAD) were similarly effective in inducing a CR in 222 of 270 (83%) patients. These patients were scheduled to receive consolidative RT to bulky disease or other critical sites of initial nodal involvement to a total dose of 2,000 cGy, with an optional additional boost of 1,000 cGy. However, only 125 (56%) patients received radiation to all initial nodal sites of disease. In 69 (31%) patients, only selected nodal sites were included in the radiation fields, and 28 (13%) did not receive any RT. Of the 222 CR patients, 42 (19%) relapsed during a median follow-up period of 6.5 years (range, 2 to 15 years). Of these, 26 (62%) patients relapsed exclusively in unirradiated nodal sites, six (14%) within irradiated sites, and 10 (24%) both within and outside irradiated fields. The actuarial 10-year relapse-free survival (RFS) and overall survival (OS) for patients receiving radiation to all initially involved nodal sites were 89% and 94%, respectively, compared with 68% and 71% (P less than .0001) for patients who had only partial or no RT. Cox proportional hazards regression analysis showed that RT to all sites of initial disease was the most significant independent covariate (P less than .005) affecting RFS and OS. These data demonstrate that residual microscopic disease is relatively frequent in patients with apparent CR after alternating combination chemotherapy, and that irradiation of all sites of initial nodal involvement decreases relapse and improves survival in advanced-stage HD.

The effects of transforming growth factor beta 3 on the growth of highly enriched hematopoietic progenitor cells derived from normal human bone marrow and peripheral blood.

The effects of transforming growth factor beta 3 (TGF-beta 3) on growth in semisolid cultures of enriched hematopoietic progenitors derived from normal human marrow and blood were evaluated. Conditioned media from the Mo-T cell line (MoCM) were the source of colony-stimulating factors used to optimally stimulate primitive progenitors. To assess whether a proportion of granulocyte/monocyte (GM) progenitors were prevented from cycling, all sizes of GM aggregates were evaluated from 3 to 20 days. The activity of TGF-beta 3 on the growth of erythroid burst-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM) was similar to that observed for TGF-beta 1. TGF-beta 3 (10, 100, and 1,000 pmol/liter), added initially or 72 h after initiation of culture, did not significantly affect the total number of marrow GM aggregates at 3, 7, 14, and 20 days, but TGF-beta 3 (1,000 pmol/liter), added initially, reduced the total number of blood GM aggregates. This suggests that some blood GM progenitors might be blocked from cycling but that the great majority of marrow GM progenitors are not blocked. Whether TGF-beta 3 (10, 100, and 1,000 pmol/liter) was added initially or after 72 h of stimulation by MoCM, there was a dose-dependent reduction of marrow and blood GM colony size even when the total number of colonies was unaffected. TGF-beta 3 (10, 100, and 1,000 pmol/liter), added initially or at 72 h, reduced in a dose-dependent manner the size of marrow and blood-derived BFU-E. TGF-beta 3 (1,000 pmol/liter) was more likely to reduce the total number of marrow and blood BFU-E, and this increased sensitivity of the erythroid lineage may prevent the development of this population in colonies derived from multipotential colony-forming unit-granulocyte/erythroid/monocyte (CFU-GEM). The results suggest that the main effect of TGF-beta 3 and TGF-beta 1 is to slow the rate of proliferation of hematopoietic progenitors rather than to prevent them from beginning proliferation. This results in a reduction in colony size which prevents the identification of primitive versus mature progenitor on the basis of standard criteria of colony size.

Proliferative response of human acute myeloid leukemia cells and normal marrow enriched progenitor cells to human recombinant growth factors IL-3, GM-CSF and G-CSF alone and in combination.

The effects of human recombinant colony-stimulating factors (r-CSFs), interleukin 3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) on inducing the growth of colonies derived from patients with acute myeloid leukemia (AML) (CFU-L) were investigated and compared to the proliferative response of CFU-GM derived from highly enriched normal blast cell populations. The effects of GM-CSF and IL-3 alone were similar. Both only minimally stimulated normal colonies derived from CFU-GM when compared to stimulation with MoCM (a mean of 28% of the total colonies and 17% of the colonies greater than 100 cells obtained with MoCM). Similarly, the number of leukemic colonies was substantially less than with MoCM (less than 30% of MoCM) in all but 3/10 AML patients and both were only able to significantly stimulate CFU-L derived colonies greater than 50 cells from 2/10 patients. G-CSF alone stimulated some CFU-L derived colony growth in 9/10 patients but the number stimulated was minimal relative to MoCM in five of the patients and significant stimulation of colonies greater than 50 cells occurred in only one patient. The mean number of normal CFU-GM derived colonies stimulated by G-CSF was 41% of the total colonies and 34% of the colonies greater than 100 cells generated by MoCM. The combination of G-CSF with GM-CSF and G-CSF with IL-3 resulted in a synergistic or additive increase in the number of CFU-L in 5/10 and 7/10 patients, respectively, and a synergistic increase in the size of CFU-L in 5/10. The same combinations resulted in a significant synergistic effect on size of normal CFU-GM derived colonies. There was no evidence of a synergistic increase in the number or size of CFU-L and CFU-GM derived colonies stimulated with GM-CSF in combination with IL-3. In addition, a combination of all three (G-CSF + GM-CSF + IL-3) did not enhance the effect of G-CSF + GM-CSF or G-CSF + IL-3. These results suggest that there is significant heterogeneity among AML patients in the pattern of responsiveness of the leukemic cells to the recombinant growth factors. In addition, their responsiveness does not significantly differ from that of normal progenitors. In view of the current clinical trials with r-CSFs and cytotoxic drugs in AML patients, this issue is important and worthy of further investigation.(ABSTRACT TRUNCATED AT 400 WORDS)

Mathematical model of granulocytopoiesis and chronic myelogenous leukemia.

We present a mathematical model of granulocytopoiesis that depends on certain physiologically meaningful parameters. By choosing different values of these parameters, the model describes both the normal process and that in chronic myelogenous leukemia (CML). The model fits all the available experimental data tested. Furthermore, it shows how the CML cells can ultimately outnumber the normal cells and how this process can be very slow. The model provides a quantitative approach to the relationship between proliferation and maturation and resolves the apparent contradiction between decreased proliferation and increased production, by assuming that a greater fraction of CML cells is produced by division rather than by maturation. The model should be helpful in designing experiments to better define the abnormalities of proliferation and maturation in CML and in seeking to define the specific alterations in the cell regulatory networks resulting from the production of the chimeric p210bcr-abl protein characteristic of CML.

Autologous bone marrow transplantation in acute myelogenous leukemia: in vitro treatment with myeloid-specific monoclonal antibodies and drugs in combination.

We report the results of a preclinical study comparing four different purging protocols using a promyelocytic human cell line HL-60 and myeloid leukemic progenitor cells (colony-forming unit-leukemic [CFU-L]) from acute myelogenous leukemia (AML) patients assayed in semisolid culture. We studied the antileukemic effect of (1) Single-cycle complement-mediated lysis by two different monoclonal antibodies (MoAbs) (M195 [CD33] and F23 [CD13] 40 micrograms/mL), reactive with distinct antigens found on early myeloid cells and monocytes, used alone and in combinations; (2) 4-Hydroperoxycyclophosphamide (4-HC) (80 mumol/L or 100 mumol/L) alone; or (3) combined with VP-16 (5 micrograms/mL) and (4) a cocktail of 1 through 3 as above (combined immunochemotherapy). More than 4 logs of HL-60 tumor cell elimination were observed after 1 hour of incubation with both MoAbs plus 4-HC + VP-16 while the single treatment (immunotherapy or chemotherapy) provided 1.5 and 3.5 logs of colony-forming inhibition, respectively. When the same protocols were tested on cryopreserved leukemic cells from eight patients with AML, we observed a mean value of CFU-L inhibition of 92.3% +/- 2.5% SD, 95.5% +/- 1.4% SD, and 99% +/- 0.8% SD after MoAbs and complement lysis, 4-HC, and 4-HC + VP-16 treatment, respectively. The combined treatment of MoAbs and 4-HC + VP-16 produced more than 3-log reduction of CFU-L colony formation. By comparison, the mean recovery of committed normal bone marrow progenitors after incubation with MoAbs and complement was 12% for CFU-granulocyte-macrophage (CFU-GM), 22.9% for burst-forming unit erythroid (BFU-E), and the recovery following 4-HC + VP-16 treatment was 4.4% for CFU-GM and 5.6% BFU-E. In subsequent experiments, highly purified CD34+ blast cells, enriched by positive selection, and stimulated in liquid culture by cytokines (interleukin-1 [IL-1], IL-3, and combination of both) or MO-conditioned medium (MoCM), demonstrated that immunochemotherapy spares hematopoietic colony-forming cells earlier than day 14 CFU-GM, in vitro.

Small non-cleaved-cell lymphoma (undifferentiated lymphoma, Burkitt's type) in American adults: results with treatment designed for acute lymphoblastic leukemia.

PURPOSE: Small non-cleaved-cell lymphoma (SNCL) "Burkitt's type," a rapidly growing lymphoma, has been rare among adults in the United States, but has greatly increased in incidence with the acquired immunodeficiency syndrome epidemic. This report details the results of treatment of adult SNCL with a series of protocols originally designed for the treatment of acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Between July 1973 and May 1987, 29 adults with newly diagnosed SNCL were treated at Memorial Hospital with intensive chemotherapy originally designed for ALL: the cyclophosphamide L-2, L-10, L-17, and L-20 protocols. Nine patients had positive serologies for human immunodeficiency virus (HIV) infection. One patient with all measurable disease resected was not evaluable for response. RESULTS: Sixteen of 28 evaluable patients (57%) achieved a complete remission with treatment. With follow-up as long as 153 months (median, 47 months), 50% of all patients and 59% of patients with negative or unknown HIV serologies have survived and are probably cured. Patients with an initial serum lactic acid dehydrogenase (LDH) level of greater than 500 U/L had a significantly shortened survival as compared with those with a lower serum LDH. Other pretreatment patient characteristics associated with a shortened survival of borderline statistical significance were high National Cancer Institute stage (C, D) and bone marrow involvement. These results are similar to those for ALL and lymphoblastic lymphoma and are comparable to those for American SNCL in the literature. CONCLUSIONS: Approximately one half of adults with SNCL are curable with intensive chemotherapy. More intensive chemotherapy with hematopoietic growth factor and/or autologous bone marrow or peripheral stem cell support may increase curability.

A phase I trial of monoclonal antibody M195 in acute myelogenous leukemia: specific bone marrow targeting and internalization of radionuclide.

Ten patients with myeloid leukemias were treated in a phase I trial with escalating doses of mouse monoclonal antibody (mAb) M195, reactive with CD33, a glycoprotein found on myeloid leukemia blasts and early hematopoietic progenitor cells but not on normal stem cells. M195 was trace-labeled with iodine-131 (131I) to allow detailed pharmacokinetic and dosimetric studies by serial sampling of blood and bone marrow and whole-body gamma-camera imaging. Total doses up to 76 mg were administered safely without immediate adverse effects. Absorption of M195 onto targets in vivo was demonstrated by biopsy, pharmacology, flow cytometry, and imaging; saturation of available sites occurred at doses greater than or equal to 5 mg/m2. The entire bone marrow was specifically and clearly imaged beginning within hours after injection; optimal imaging occurred at the lowest dose. Bone marrow biopsies demonstrated significant dose-related uptake of M195 as early as 1 hour after infusion in all patients, with the majority of the dose found in the marrow. Tumor regressions were not observed. An estimated 0.33 to 1.0 rad/mCi 131I was delivered to the whole body, 1.1 to 6.1 rad/mCi was delivered to the plasma, and up to 34 rad/mCi was delivered to the red marrow compartment. 131I-M195 was rapidly modulated, with a majority of the bound immunoglobulin G (IgG) being internalized into target cells in vivo. These data indicate that whole bone marrow ablative doses of 131I-M195 can be expected. The rapid, specific, and quantitative delivery to the bone marrow and the efficient internalization of M195 into target cells in vivo also suggest that the delivery of other isotopes such as auger or alpha emitters, toxins, or other biologically important molecules into either leukemia cells or normal hematopoietic progenitor cells may be feasible.

Factors affecting the outcome of autologous bone marrow transplantation.

Various protocols have been used at Memorial Sloan-Kettering Cancer Center to improve the results of autologous bone marrow transplantation (ABMT) for hematopoietic malignancies. Results suggest that patients who undergo ABMT while in complete remission (after induction or reinduction treatment) do better than those who undergo ABMT in incomplete remission. In patients with relapsed or refractory lymphoma, the addition of etoposide to the total body irradiation/cyclophosphamide conditioning regimen has decreased the relapse rate from 53% to 7%. For patients with refractory or relapsed Hodgkin's disease, the dosages of different drugs can be altered to improve the overall success. Dose escalation of etoposide shows significant promise. Relapse after ABMT and/or toxic complications are the main factors that need to be addressed in the future. Pulmonary toxicity occurs mainly in patients with mediastinal disease. Factors that can decrease relapse rate and toxicity are discussed.

Prognostic factors among 185 adults with newly diagnosed advanced Hodgkin's disease treated with alternating potentially noncross-resistant chemotherapy and intermediate-dose radiation therapy.

The initial promising results with alternating chemotherapy regimens (mechlorethamine, vincristine, procarbazine, and prednisone/doxorubicin, bleomycin, vinblastine, and dacarbazine [MOPP/ABVD]; lomustine, melphalan, and vindesine [CAD] plus MOPP plus ABV) combined with intermediate-dose radiation therapy (RT) have been sustained with further follow-up; 82.2% of patients (152 of 185) achieved a complete remission (CR), and overall survival is 71.7% +/- 4.4% at 8 years (median follow-up is 55 months among the survivors). No statistically significant differences were found in CR percentage, CR duration, or survival between stages IIB, IIIB, and IV patients. For that reason, stepwise Cox regression analyses to identify the important prognostic factors were performed on overall survival, tumor mortality, freedom from disease progression, and survival following disease progression. Pretreatment characteristics were also tested for association with the probability of achieving CR, CR duration, and death due to other causes. Characteristics that were consistently associated with an independently unfavorable prognosis were low hematocrit, high serum lactic acid dehydrogenase (LDH), age more than 45 years, inguinal node involvement, mediastinal mass greater than .45 of the thoracic diameter, and bone marrow involvement. Patients with two or more unfavorable characteristics were much more likely to fail treatment (median survival, 62.4 months) than those with none or only one unfavorable factor (greater than 95% survival). This striking difference between the low- and high-risk groups remained even if the comparison was restricted to patients less than or equal to 45 years of age. These results provide a basis for selecting the young patients at high risk of failure for more intensive initial treatment with either autologous bone marrow rescue or hematopoietic growth factors.