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Biomedical subjects

D Colomer

Publications and source records attributed to D Colomer.

At least 19 recordsLinked to original sources

Outcome of patients with acute promyelocytic leukemia failing to front-line treatment with all-trans retinoic acid and anthracycline-based chemotherapy (PETHEMA protocols LPA96 and LPA99): benefit of an early intervention.

To determine prognosis of acute promyelocytic leukemia (APL) failing to front-line therapy with all-trans retinoic acid (ATRA) and anthracyclines, outcome of 52 patients (32 M/20 F; age: 37, 3-72) included in PETHEMA trials LPA96 and LPA99 who presented with either molecular failure (MOLrel, n=16) or hematological relapse (HEMrel, n=36) was analyzed. Salvage therapy consisted of ATRA and high-dose ara-C-based chemotherapy (HDAC) in most cases (83%), followed by stem-cell transplantation (autologous, 18; allogeneic, 10; syngeneic, 1). Fourteen patients with MOLrel (88%) achieved second molecular complete response (molCR), whereas 81% HEMrel patients responded to second-line treatment, with 58% molCR. After median follow-up of 45 months, four MOLrel and 18 HEMrel patients, respectively, experienced a second relapse. Outcome after MOLrel compared favorably to HEMrel, with longer survival (5-year survival: 64+/-14 vs 24+/-8%, P=0.01) and lower relapse risk (5-year relapse risk: 30+/-13 vs 64+/-9%; P=0.044). Additionally, age <or=40 and male gender were favorable variables for survival, whereas molecular response predicted longer leukemia-free survival. In conclusion, early institution of salvage therapy at molecular failure, before onset of hematological relapse, is beneficial in APL. Moreover, given the poor outcome of HEMrel managed with ATRA and HDAC, use of alternative therapeutic strategies in this setting is warranted.

Adolescent↗

Coding sequence and intron-exon junctions of the c-myb gene are intact in the chronic phase and blast crisis stages of chronic myeloid leukemia patients.

The c-myb gene encodes a transcription factor required for proliferation, differentiation and survival of normal and leukemic hematopoietic cells. c-Myb has a longer half-life in BCR/ABL-expressing than in normal cells, a feature which depends, in part, on PI-3K/Akt-dependent regulation of proteins interacting with the leucine zipper/negative regulatory region of c-Myb. Thus, we asked whether the stability of c-Myb in leukemic cells might be enhanced by mutations interfering with its degradation. We analyzed the c-myb gene in 133 chronic myeloid leukemia (CML) patients in chronic phase and/or blast crisis by denaturing-high performance liquid chromatography (D-HPLC) and sequence analysis of PCR products corresponding to the entire coding sequence and each exon-intron boundary. No mutations were found. We found four single nucleotide polymorphisms (SNPs) and identified an alternatively spliced transcript lacking exon 5, but SNPs frequency and expression of the alternatively spliced transcript were identical in normal and CML cells. Thus, the enhanced stability of c-Myb in CML blast crisis cells and perhaps in other types of leukemia is not caused by a genetic mechanism.

Base Sequence↗

Equilibrative nucleoside transporter-2 (hENT2) protein expression correlates with ex vivo sensitivity to fludarabine in chronic lymphocytic leukemia (CLL) cells.

Fludarabine is considered the treatment of choice for most patients with chronic lymphocytic leukemia (CLL). We have analyzed the role of plasma membrane transporters in nucleoside-derived drug bioavailability and action in CLL cells. Among the known plasma membrane transporters, we have previously observed a significant correlation between fludarabine uptake via ENT carriers and ex vivo sensitivity of CLL cells to fludarabine, although mRNA amounts of the equilibrative nucleoside transporters hENT1 and hENT2 do not show any predictive response to treatment. In this study, using polyclonal monospecific antibodies we have observed a significant correlation between the expression of hENT2 by Western blot and fludarabine uptake via hENT carriers and also with ex vivo sensitivity of CLL cells to fludarabine. These results suggest that the equilibrative nucleoside transporter hENT2 plays a role in fludarabine responsiveness in CLL patients.

Antineoplastic Agents↗

Nucleoside transporters in chronic lymphocytic leukaemia.

Nucleoside derivatives have important therapeutic activity in chronic lymphocytic leukaemia (CLL). Experimental evidence indicates that in CLL cells most of these drugs induce apoptosis ex vivo, suggesting that programmed cell death is the mechanism of their therapeutic action, relying upon previous uptake and metabolic activation. Although defective apoptosis and poor metabolism often cause resistance to treatment, differential uptake and/or export of nucleosides and nucleotides may significantly modulate intracellular drug bioavailability and, consequently, responsiveness to therapy. Two gene families, SLC28 and SLC29, encode transporter proteins responsible for concentrative and equilibrative nucleoside uptake (CNT and ENT, respectively). Furthermore, selected members of the expanding ATP-binding cassette (ABC) protein family have recently been identified as putative efflux pumps for the phosphorylated forms of these nucleoside-derived drugs, ABCC11 (MRP8) being a good candidate to modulate cell sensitivity to fluoropyrimidines. Sensitivity of CLL cells to fludarabine has also been recently correlated with ENT-type transport function, suggesting that, besides the integrity of apoptotic pathways and appropriate intracellular metabolism, transport across the plasma membrane is also a relevant event during CLL treatment. As long as nucleoside transporter expression in leukaemia cells is not constitutive, the possibility of regulating nucleoside transporter function by pharmacological means may also contribute to improve therapy.

Animals↗

Tissue production of pro-inflammatory cytokines (IL-1beta, TNFalpha and IL-6) correlates with the intensity of the systemic inflammatory response and with corticosteroid requirements in giant-cell arteritis.

OBJECTIVES: To investigate proinflammatory cytokine expression in temporal arteries from patients with giant-cell arteritis (GCA) and to analyse its relationship with the intensity of the initial systemic inflammatory reaction and response to corticosteroid therapy. METHODS: Quantification of interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6) mRNA by real-time quantitative PCR in temporal artery samples from 36 patients with biopsy-proven GCA and 11 controls. Immunohistochemical detection of IL-1beta, TNFalpha, and IL-6 in temporal artery sections from 74 patients with GCA and 15 controls. Clinical and biochemical parameters of inflammation as well as the time (weeks) required to reach a maintenance prednisone dose <10 mg/day were recorded. RESULTS: IL-1beta (13.8 +/- 2.5 vs 5.4 +/- 1.3 relative units, P = 0.012) and IL-6 transcripts (34 +/- 13.7 vs 7.8 +/- 4.5 relative units, P = 0.034) were significantly more abundant in patients with a strong systemic inflammatory response compared with those with no inflammatory parameters. Immunohistochemical scores for IL-1beta (2.7 +/- 0.3 vs 1.9 +/- 0.2, P = 0.018), TNFalpha (3.2 +/- 0.2 vs 2.4 +/- 0.3, P = 0.028) and IL-6 (3 +/- 0.2 vs 2.1 +/- 0.3, P = 0.023) were also significantly higher in patients with strong systemic inflammatory reaction. A significant correlation was found between the amount of tissue TNFalpha mRNA and the time required to reach a maintenance dose of prednisone <10 mg/day (r = 0.586, P = 0.001). CONCLUSION: GCA patients with a strong systemic inflammatory response, who have been previously shown to be more resistant to corticosteroid therapy, have elevated tissue expression of proinflammatory cytokines IL-1beta, TNFalpha and IL-6. High production of TNFalpha is associated with longer corticosteroid requirements.

Acute-Phase Reaction↗

Diffuse large B-cell lymphoma arising from donor lymphoid cells after renal and pancreatic transplantation.

A patient with both a renal and pancreatic transplantation developed a diffuse large B-cell lymphoma, Epstein-Barr virus-related, 14 months after the surgical procedure. Tumor was confined to the transplanted organs: head of the pancreas and hilar lymph node of the transplanted kidney. Chimerism analysis demonstrated the tumor origin from donor lymphoid cells. Immunosuppression was discontinued and chemotherapy with cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone (CHOP) was started. However, no response was observed after three courses of this regimen. Finally, a transplantectomy was carried out, followed by rituximab (anti-CD20 antibody), with the patient achieving a complete response (CR). Two years later the patient remains in CR.

Adult↗

Acute myeloid leukemia with MLL rearrangements: clinicobiological features, prognostic impact and value of flow cytometry in the detection of residual leukemic cells.

The MLL gene, located at 11q23 band, is frequently disrupted by different chromosomal rearrangements that occur in a variety of hematological malignancies. MLL rearrangements are associated with distinct clinical features and a poor prognosis. The aim of this study was to analyze the incidence and the prognostic significance of MLL rearrangements in a consecutive series of adult AML patients and to determine the immunophenotypic features of these cases. The identification of abnormal immunophenotypes could be used for the detection of minimal residual disease (MRD). Ninety-three adult patients with de novo acute myeloid leukemia (AML) were analyzed by Southern blot in order to detect MLL rearrangements (MLL+). RT-PCR and genomic long-range PCR were performed to further characterize MLL partial tandem duplication (PTD) in those patients in whom conventional karyotype did not show 11q23 chromosomal translocations. All the patients were homogeneously immunophenotyped at diagnosis. MLL rearrangements were detected in 13 (14%) patients. Four patients (5%) showed 11q23 translocations by karyotypic conventional analysis. Nine patients (10%) revealed PTD of MLL and one patient showed a MLL cleavage pattern. The MLL+ patients usually expressed myeloid and monocytic antigens CD33 (12/13 cases), CD13 (9/13), CD117 (9/13), CD64 (11/13) and in some cases CD14 (4/11). HLA-DR was also positive in (12/13). Eight out of 13 cases expressed the stem cell marker CD34. Only one patient revealed lymphoid marker reactivity (CD7) and CD56 was expressed in 5/13 cases. All the MLL+ patients showed at least one aberrant phenotype at diagnosis, which allowed us to set out a simple panel for the MRD studies. Twenty-seven samples from eight patients in morphologic complete remission (CR) were analyzed using the aberrant immunologic combinations detected at diagnosis. Phenotypically abnormal cells were detected in all the patients who subsequently relapsed, whereas only one patient with MRD+ remained in CR. Owing to the high level of residual leukemic cells, the MLL+ patients showed a short CR duration and a poor survival. In conclusion, immunophenotyping may be a suitable approach to investigating MRD status in AML patients with PTD of the MLL gene.

Acute Disease↗

Serial quantification of lymphoid and myeloid mixed chimerism using multiplex PCR amplification of short tandem repeat-markers predicts graft rejection and relapse, respectively, after allogeneic transplantation of CD34+ selected cells from peripheral blood.

We used multiplex amplification of nine microsatellite sequences (PCR-STR) to analyse chimerism in pure populations of T cells and neutrophils from peripheral blood from 40 patients submitted to an allogeneic transplant, 22 having received a T-cell depleted (TCD) peripheral blood graft by means of CD34(+) selection (allo-PBT/CD34(+)), and 18, an unmodified graft (allo-SCT; 13 allogeneic bone marrow transplants and five allo-PBT). T-cell mixed chimerism (TcMC) was observed in 16 of the 22 (72.3%) patients receiving an allo-PBT/CD34(+), but in only one of the 18 (5.5%) patients receiving an allo-SCT (P=0.0001). TcMC was transient (n=6), stable (n=7), and associated with poor haematopoietic engraftment (n=4). All patients with TcMC who developed graft failure had more than 30% of host T cells. Myeloid MC (MyMC) was observed in four (19%) allo-PBT/CD34(+) patients and in three (17%) allo-SCT patients (P=NS). Five out of seven (71%) patients with MyMC relapsed, all of them diagnosed with myeloid malignancies, as compared with two of the 20 (10%) patients with complete donor chimerism (P&<0.0001). In conclusion, TcMC appears in a significant number of allo-PBT/CD34(+) patients and may be associated with poor engraftment when the percentage of host T cells is >30%; likewise, MyMC appears in a small percentage of recipients of both allo-PBT/CD34(+) and allo-SCT patients, and is associated with leukaemia relapse in myeloid malignancies.

Adult↗

Prodigiosin induces apoptosis of B and T cells from B-cell chronic lymphocytic leukemia.

We have previously reported that prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosene) induces apoptosis in human hematopoietic cancer cell lines with no marked toxicity in nonmalignant cell lines. In this study, we demonstrate that prodigiosin induces apoptosis of B-cell chronic lymphocytic leukemia (B-CLL) cells (n=32 patients). The dose-response for the cytotoxic effect of prodigiosin was analyzed in cells from 12 patients showing an IC(50) of 116+/-25 nM. Prodigiosin induced apoptosis of B-CLL cells through caspase activation. We also analyzed the cytotoxic effect of prodigiosin in T cells from B-CLL samples and no differences were observed with respect to leukemia cells. This is the first report showing that prodigiosin induces apoptosis in human primary cancer cells.

Antiporters↗

Simultaneous diagnosis of hairy cell leukemia and chronic lymphocytic leukemia/small lymphocytic lymphoma: a frequent association?

The association of hairy cell leukemia (HCL) with other neoplasms, mainly non-Hodgkin's lymphomas, is well known. However, the simultaneous diagnosis of HCL and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is rare, with only few cases of such an association having been reported. We describe three patients with a well-characterized HCL in whom a CLL/SLL population was detected. Of note, these cases represent a significant proportion (11.5%; 95% CI: 0% to 24%) of the total number of HCL cases diagnosed in our institution during the same period of time. All three patients were treated with deoxycoformycin. They achieved a complete response of the HCL, whereas the CLL/SLL population persisted in all cases. The immunoglobulin gene rearrangement analysis, in two informative cases, suggested that the HCL and CLL/SLL populations arose from different B cell clones. This study indicates that the association of HCL and CLL/SLL might be much more frequent than previously recognized. Therefore, a large panel of monoclonal antibodies, including those necessary to detect CLL/SLL, should be employed when studying patients with HCL.

Antimetabolites, Antineoplastic↗

Survival after progression in patients with follicular lymphoma: analysis of prognostic factors.

BACKGROUND: The purpose of this study was to identify prognostic parameters for patients with follicular lymphoma (FL) in first progression/relapse. These would be useful for selection of high-risk patients for inclusion in trials aimed at determining the effect of new treatment approaches in such patients. PATIENTS AND METHODS: Ninety patients (48 male, 42 female, median age 56 years) diagnosed with FL, in a single institution during a 20 year period and relapsing/progressing after an initial response to therapy, were recruited. The main end-point of the study was survival from progression (SFP). Univariate and multivariate analyses were performed, including among the predictive variables the response duration (RD) after the initial treatment and the main features of the patients at the first progression or relapse. RESULTS: Five-year SFP was 47% (95% confidence interval 35% to 58%). Patients with RD following initial therapy >2 years had a longer SFP (5-year SFP 63 versus 33%, P = 0.012). Other variables with prognostic interest for SFP were stage at diagnosis and the following variables at relapse: age, bulky disease, performance status, serum lactate dehydrogenase level, serum beta2-microglobulin level, bone marrow involvement, stage and International Prognostic Index rating. In the multivariate analysis, poor performance status at progression and a RD <2 years were the most important unfavorable variables to predict SFP. CONCLUSION: In patients with FL, RD along with performance status at progression are features that predict SFP. These variables could thus be useful to select candidates for experimental treatments.

Age Factors↗

Complement-mediated cell death induced by rituximab in B-cell lymphoproliferative disorders is mediated in vitro by a caspase-independent mechanism involving the generation of reactive oxygen species.

Mechanisms involving the in vitro effect of rituximab in cells from 55 patients with B-cell lymphoproliferative disorders were investigated. No cytotoxic effect was observed when cells were incubated with rituximab alone, but in the presence of human AB serum rituximab induced complement-dependent cell death (R-CDC). A cytotoxic effect was observed in cells from 9 of 33 patients with B-cell chronic lymphocytic leukemia, 16 of 16 patients with mantle-cell lymphoma, 4 of 4 patients with follicular lymphoma, and 2 of 2 patients with hairy-cell leukemia. R-CDC was observed in cells from patients expressing more than 50 x 10(3) CD20 molecules per cell, and directly correlated with the number of CD20 molecules per cell. Preincubation with anti-CD59 increased the cytotoxic effect of rituximab and sensitized cells from nonsensitive cases. Neither cleavage of poly-ADP ribose polymerase (PARP) nor activation of caspase-3 was observed in R-CDC. In addition, no cells with a hypodiploid DNA content were detected and R-CDC was not prevented by a broad-spectrum caspase inhibitor, suggesting a caspase-independent mechanism. Incubation with rituximab in the presence of AB serum induced a rapid and intense production of reactive oxygen species (ROS). R-CDC was blocked by the incubation of cells with N-acetyl-L-cysteine (NAC) or Tiron, 2 ROS scavengers, indicating that the cytotoxic effect was due to the generation of superoxide (O) radicals. In conclusion, the results of the present study suggest that CD20, CD59, and complement have a role in the in vitro cytotoxic effect of rituximab, which is mediated by a caspase-independent process that involves ROS generation.

Adult↗

BMI-1 gene amplification and overexpression in hematological malignancies occur mainly in mantle cell lymphomas.

The BMI-1 gene is a putative oncogene belonging to the Polycomb group family that cooperates with c-myc in the generation of mouse lymphomas and seems to participate in cell cycle regulation and senescence by acting as a transcriptional repressor of the INK4a/ARF locus. The BMI-1 gene has been located on chromosome 10p13, a region involved in chromosomal translocations in infant leukemias, and amplified in occasional non-Hodgkin's lymphomas (NHLs) and solid tumors. To determine the possible alterations of this gene in human malignancies, we have examined 160 lymphoproliferative disorders, 13 myeloid leukemias, and 89 carcinomas by Southern blot analysis and detected BMI-1 gene amplification (3- to 7-fold) in 4 of 36 (11%) mantle cell lymphomas (MCLs) with no alterations in the INK4a/ARF locus. BMI-1 and p16INK4a mRNA and protein expression were also studied by real-time quantitative reverse transcription-PCR and Western blot, respectively, in a subset of NHLs. BMI-1 expression was significantly higher in chronic lymphocytic leukemia and MCL than in follicular lymphoma and large B cell lymphoma. The four tumors with gene amplification showed significantly higher mRNA levels than other MCLs and NHLs with the BMI-1 gene in germline configuration. Five additional MCLs also showed very high mRNA levels without gene amplification. A good correlation between BMI-1 mRNA levels and protein expression was observed in all types of lymphomas. No relationship was detected between BMI-1 and p16INK4a mRNA levels. These findings suggest that BMI-1 gene alterations in human neoplasms are uncommon, but they may contribute to the pathogenesis in a subset of malignant lymphomas, particularly of mantle cell type.

Cyclin-Dependent Kinase Inhibitor p16↗

Stem cell transplantation for chronic lymphocytic leukemia: different outcome after autologous and allogeneic transplantation and correlation with minimal residual disease status.

The clinical outcome and its correlation with the status of minimal residual disease (MRD) was analyzed in 26 patients with chronic lymphocytic leukemia (CLL) undergoing stem cell transplantation. All patients having received autotransplant (n = 14) achieved CR which was MRD(-) in nine patients (64%) and MRD(+) in five. With a median follow-up of 26.5 months (range, 12-52), four of the five MRD(+) patients relapsed at 9, 15, 17 and 18 months after transplant, respectively. In contrast, only two patients of the nine MRD(-) patients have relapsed at 15 and 38 months (P = 0.02), and four became MRD(+) at 6, 12, 30, and 42 months after transplantation, respectively. Of the 12 patients that were allografted, three (25%) died in the early post-transplant period, one had resistant disease, and eight (67%) achieved CR. Among the latter, no evidence of MRD post-transplantation was observed in five cases, while a delayed clearance of MRD (up to 22 months after transplantation) was seen in two, and a persistent positivity of MRD after transplant was detectable in another patient until last follow-up (12 months). After a median follow-up of 43 months (range, 15-106), none of the responding patients had clinical or MRD relapse. These results show that in CLL the probability of achieving sustained MRD(-) CR is higher with allogeneic than with autologous transplants, and confirm the value of MRD assessment in the follow-up of patients transplanted for CLL.

Graft vs Host Disease↗

Pretreatment characteristics and clinical outcome of acute promyelocytic leukaemia patients according to the PML-RAR alpha isoforms: a study of the PETHEMA group.

Of 167 newly diagnosed acute promyelocytic leukaemia patients, 83 patients were long (L)-form (50%), eight variable (V)-form (5%) and 76 short (S)-form (45%). The V-form and S-form groups presented a significantly higher percentage of patients with white blood cell counts > 10 x 10(9)/l (P < 0.05). The S-form cases displayed a significantly higher number of cases with M3v microgranular features (P = 0.005) and CD34 expression (P < 0.0001). There were no differences between the three isoforms in complete remission (CR) rate (overall CR 90%), but the 3-year disease-free survival was lower for V-form cases than it was for L- and S-form cases (62% vs. 94% and 89%, P = 0.056). We conclude that the V-form and S-form types are associated with some negative prognostic features at diagnosis. However, our data were only able to demonstrate an association with adverse prognosis in the V-form type and, moreover, as the number of cases was limited, needs to be confirmed in large, uniformly treated series.

Adolescent↗

Microsatellite instability analysis in typical and progressed mantle cell lymphoma and B-cell chronic lymphocytic leukemia.

BACKGROUND AND OBJECTIVES: Microsatellite instability (MSI) is characterized by tumor-associated alterations in the germline size of microsatellite repeats caused by a reduced efficacy of the DNA mismatch repair machinery. The aim of this study was to investigate the presence of MSI in a number of cases of indolent and aggressive mantle cell lymphoma (MCL) and B-cell chronic lymphocytic leukemia (B-CLL) to determine its possible role in the initial development and progression of these disorders. DESIGN AND METHODS: We examined the presence of MSI in 28 B-CLL, 24 typical and 4 transformed B-CLL (Richter's syndrome) and 29 MCL, 19 typical and 10 blastoid variants by using a panel of 10 microsatellite markers and analyzed them using an AbiPrism 310 DNA sequencer. Fisher's exact test was used to compare categorical variables and Mann-Whitney's U-test for continuous variables. RESULTS: MSI alterations were not observed in any case of MCL or Richter's syndrome and in only three (13%) patients with typical B-CLL. Two of these patients also had loss of heterozygosity in one of the 10 sites examined. These patients presented with a more advanced stage, diffuse bone marrow involvement, and poorer performance status than patients without these alterations. INTERPRETATION AND CONCLUSIONS: These findings indicate that MSI is not involved in the pathogenesis or progression of B-CLL and MCL but may appear in a small subset of patients with advanced B-CLL.

Adult↗

Variability in the levels of PML-RAR alpha fusion transcripts detected by the laboratories participating in an external quality control program using several reverse transcription polymerase chain reaction protocols.

BACKGROUND AND OBJECTIVES: The detection of PML-RAR by reverse transcription (RT) polymerase chain reaction (PCR) in acute promyelocytic leukemia (APL) patients who are in hematologic remission influences therapeutic decision making in several trials. In the light of this, the Spanish group has recently designed an external quality assessment program (EQAP) of RT-PCR detection of PML-RAR, which includes a study of sensitivity of the participating laboratories. DESIGN AND METHODS: Eighteen laboratories were involved in the program. Ten laboratories followed the method of Biondi et al., 5 employed that of Borrow et al. and the 3 remaining used other protocols. The sensitivity was studied in five rounds of quality control. The first two shipments consisted of dilutions of NB4 RNA into non-APL RNA. The third round consisted of serial dilutions of the NB4 cell line into HL60 cells. The fourth and five rounds consisted of plasmid dilutions containing the bcr1 and bcr3 PML-RAR isoforms. RESULTS: The results showed that the distinct methods allow detection of the PML-RAR hybrid up to a dilution of 10(-4), and exceptionally, up to 10(-5). The laboratories following the method of Biondi et al. usually detected the 10(-3) dilution and less frequently the 10(-4) one, whereas those using other methods usually detected PML-RAR transcript in the 10(-4) dilution, and less commonly in the 10(-5) dilution. However, each of the PCR methods used by EQAP participating laboratories successfully detected at least 50 copies of PML-RAR alpha fusion transcript in plasmid dilution controls. INTERPRETATION AND CONCLUSIONS: The results point to heterogeneous sensitivity amongst participating laboratories. This may reflect differences in methodology, although variations in sample quality may also account for discrepant findings.

Humans↗

Definition of relapse risk and role of nonanthracycline drugs for consolidation in patients with acute promyelocytic leukemia: a joint study of the PETHEMA and GIMEMA cooperative groups.

Preliminary independent reports of the Italian GIMEMA and the Spanish PETHEMA trials for newly diagnosed acute promyelocytic leukemia (APL) indicated a similarly high antileukemic efficacy in terms of complete remission and disease-free survival rates. To better investigate these studies and the prognostic factors influencing relapse risk, this study analyzed the updated results of 217 patients with PML/RAR alpha-positive APL enrolled in GIMEMA (n = 108) and PETHEMA (n = 109). All patients received identical induction (AIDA schedule) and maintenance. For consolidation, GIMEMA patients received 3 courses including idarubicin/cytarabine, mitoxantrone/etoposide, and idarubicin/cytarabine/thioguanine, whereas PETHEMA patients received the same drugs and dose schedule of idarubicin and mitoxantrone with the omission of nonintercalating agents. Depending on whether molecular relapses were classified as censored or uncensored events, the 3-year Kaplan-Meier estimates of relapse-free survival (RFS) for the combined series were 90 +/- 2% and 86 +/- 2%, respectively. Minor differences observed between the 2 patient cohorts were negligible. Multivariate regression analysis of RFS showed that initial leukocyte (WBC) and platelet counts were the only variables with independent prognostic value. The resulting predictive model for RFS demonstrated its capability of segregating patients into low-risk (WBC count </= 10 x 10(9)/L, platelet count > 40 x 10(9)/L), intermediate-risk (WBC count </= 10 x 10(9)/L, platelets </= 40 x 10(9)/L), and high-risk (WBC count > 10 x 10(9)/L) groups, with distinctive RFS curves (P <.0001). The conclusions are that omission of nonanthracycline drugs from the AIDA regimen is not associated with reduced antileukemic efficacy and a simple predictive model may be used for risk-adapted therapy in this disease. (Blood. 2000;96:1247-1253)

Adolescent↗