Adult acute lymphoblastic leukemia: a multicentric randomized trial testing bone marrow transplantation as postremission therapy. The French Group on Therapy for Adult Acute Lymphoblastic Leukemia.

PURPOSE: In a prospective multicenter study, we analyzed the benefits of allogeneic bone marrow transplantation (BMT) in a nonselected group of adult patients with acute lymphoblastic leukemia (ALL) and, by a randomized trial, evaluated the effectiveness of autologous BMT over chemotherapy as postremission therapy in patients younger than 50 years who were not candidates for allogeneic BMT. PATIENTS AND METHODS: After induction therapy that randomized patients to receive one of two anthracycline-containing regimens, either daunorubicin (DNR) or zorubicin (ZRB), patients were assigned to postremission treatment according to age and results of HLA typing. Patients younger than 40 years with an HLA-identical sibling (group 1) were scheduled to receive cyclophosphamide 60 mg/kg on days 1 and 2, total-body irradiation (TBI), and allogeneic BMT. Patients older than 50 years (group 2) received the chemotherapy arm composed of three monthly consolidation courses (DNR or ZRB, cytarabine, and asparaginase) followed by maintenance chemotherapy (modified L10 regimen). The remaining population (group 3) was randomly assigned to receive, after the three 1-month consolidation courses, either the chemotherapy arm or autologous BMT following a conditioning regimen similar to that of group 1. RESULTS: Of the 572 assessable patients, 436 achieved complete remission (78% +/- 2% for DNR v 74% +/- 3% for ZRB; P = .3). The estimated 3-year disease-free survival (DFS) rate for the 116 patients included in group 1 was 43% +/- 5%. Both autologous BMT (95 patients) and chemotherapy (96 patients) produced comparable 3-year DFS rates (39% +/- 5% v 32% +/- 5%) and survival durations (49% +/- 5% v 42% +/- 5%). However, late relapses after 36 months were mainly observed in the chemotherapy arm. CONCLUSION: This first interim analysis did not demonstrate a benefit of this autologous BMT procedure over classical maintenance chemotherapy in patients with ALL who received consolidation chemotherapy.

Autologous peripheral-blood progenitor-cell support following high-dosechemotherapy or chemoradiotherapy in patients with high-risk multiple myeloma.

PURPOSE: The aims of the current study were to evaluate in patients with high-risk multiple myeloma (MM) the feasibility and usefulness of high-dose chemotherapy or chemoradiotherapy followed by hematopoietic stem-cell support with autologous peripheral-blood progenitor cells (PBPC) harvested after high-dose cyclophosphamide (HDCYC). PATIENTS AND METHODS: Seventy-three patients with high-risk MM were entered onto the study. Before the procedure, all patients had received HDCYC to collect PBPC by leukapheresis. One patient died of infection after HDCYC. All other patients subsequently received high-dose melphalan (HDM) (140 mg/m2) either alone (n = 1) or associated with either busulfan (16 mg/kg; n = 4) or total-body irradiation (TBI) (8 to 15 Gy; n= 67). In addition, three of the latter patients received cyclophosphamide (120 mg/kg). Thereafter, PBPC were reinfused either alone in 61 patients or together with back-up bone marrow cells in 11 patients in whom the granulocyte-macrophage colony-forming unit (CFU-GM) cell content of the leukapheresis was low. RESULTS: One patient died of acute cardiac failure after reinfusion of PBPC; three patients did not respond after autologous blood progenitor cell transplantation (ABPCT), while the other 68 patients achieved either a complete response (CR; n = 32) or partial response (PR; n = 36). Thirty-six patients relapsed or progressed after a median response duration of 14.5 months (range, 3 to 43) and 19 of these subsequently died. Four other patients died while still responsive of lung cancer (n = 1) or infection (n = 3). The remaining 28 patients are currently alive and still responding with a median follow-up duration of 27 months (range, 6 to 66). The 3-year probability of survival was 66% +/- 12% (95% confidence interval [CI] after ABPCT and 77% +/- 51% (95% CI) from diagnosis. CONCLUSION: High-dose chemotherapy or chemoradiotherapy followed by autologous PBPC support in MM is feasible and efficient. Further studies are needed to confirm these encouraging, although preliminary, results and to compare this technique with other therapeutic strategies.

Peripheral neuropathy after autologous blood stem cell transplantation for multiple myeloma.

We report a case of peripheral neuropathy occurring after autologous blood stem cell transplantation (ABSCT) for multiple myeloma. The patient, free of neurological symptoms, was transplanted in partial remission, and achieved a complete remission after transplantation. A severe peripheral, symmetric, distal sensori-motor polyneuropathy appeared at day 25 and worsened progressively until commencement of corticosteroid therapy. A peripheral nerve biopsy showed endoneurial cellular infiltrates which were predominantly composed of T cells identified by immunocytochemistry. Ultrastructural examination showed acute axonal damage. Electrophysiologic studies performed before and during the treatment were consistent with a severe axonal degeneration and showed a marked improvement, concomitant with the favorable clinical outcome. This is the first report of peripheral neuropathy after ABSCT.

Complete cytogenetic conversion in chronic myelocytic leukemia patients undergoing interferon alpha therapy: follow-up with reverse polymerase chain reaction.

Fifteen chronic myelocytic leukemia patients in durable complete cytogenetic conversion (CCC) under interferon therapy, were monitored every three to six months by bone marrow (BM) karyotypes and/or reverse-transcription polymerase chain reaction (RT-PCR) on peripheral blood (PB) leukocytes (by a nested primer approach using two rounds of amplification, 30 cycles each). Special care was taken to minimize the risk of contamination. The median time of follow-up after first CCC was 12 months (range, 6-30). Thirty five BM karyotypes were performed. Only three patients demonstrated the transient reappearance of a few Philadelphia-positive metaphases, while other patients remained in CCC. Forty five PB samples were studied by RT-PCR. In two patients, no BCR/ABL transcript could be detected in three consecutive samples. In the 13 other cases, RT-PCR was intermittently negative, indicating a level of residual leukemic cells close to the threshold of sensitivity of the technique.

Acute nonlymphocytic leukemia with marrow eosinophilia and chromosome 16 abnormality: a report of 18 cases.

This article reports 18 cases of acute nonlymphocytic leukemia (ANLL) and abnormal chromosome 16. Thirteen had the same hematological pattern at diagnosis, i.e., peripheral blood hyperleukocytosis with high percentage of monocytes and blast cells, and bone marrow showing three different cell populations: (a) myeloblasts, (b) monocytes and promonocytes, and (c) abnormal eosinophils. In these cases the diagnosis was acute myelomonocytic leukemia with bone marrow eosinophilia, as described. However three other cases were of the M5 type and two others of the M2 type, all showing an abnormal eosinophilia in their bone marrow. All cases showed an abnormal chromosome 16 in the bone marrow cells: inv (16) in 13 cases, t (16;16) in two, del (16) in one of poor quality, and in two other translocations involving band 16q22. In one case the inv (16) was found in a subclone, indicating that it could be a secondary cytogenetic defect. Five patients died soon after diagnosis; the other 13 had a median complete remission duration of 8 months. The central nervous system was frequently involved upon relapse. We do not support the hypothesis that patients with M4-Eo ANLL and chromosome 16 abnormality have a favorable prognosis.

Chronic myelocytic leukemia patients achieving complete cytogenetic conversion under interferon alpha therapy: minimal residual disease follow-up.

We report minimal residual disease evaluation in 18 chronic myelocytic leukemia patients who achieved a durable complete cytogenetic conversion (CCC) under interferon alpha (IFN) therapy. Monitoring was performed every 3-6 months using bone marrow (BM) karyotypes and/or two-step reverse transcription polymerase chain reaction (RT-PCR) on peripheral blood samples. Median follow-up after first CCC was 47 months (range 15-69). All patients maintained complete hematological remission during follow-up. A median of five BM karyotypes were performed per patient (range: 3-11). The estimated chances of maintaining a major cytogenetic response (either CCC or less than 35% Ph positive metaphases were 93 +/- 13% (95% CI) at 36 months. One patient lost his cytogenetic response. A median of seven RT-PCR reactions were performed per patient (range: 1-11). A residual disease was detectable even in cases with long periods of CCC. However, in two patients, RT-PCRs were often negative; one, who had four successive negative RT-PCR was taken off IFN therapy and did not receive any other treatment; later in this case, RT-PCRs were again positive, but CCC was maintained for 39 months. Of the three who were taken off IFN and no longer treated, two maintained CCC (39+ and 33+ months); the third had a recurrence of 7% Ph-positive metaphases, and later returned to CCC. These results confirm that in most well-responding patients, the disease is not eradicated. However, it seems that the clonogenic potential of the residual leukemic clone is low. In patients taken off IFN therapy, IFN may have a particular remnant effect.

Autografting in chronic myeloid leukemia: an overview.

Autografting could become a promising treatment for patients with chronic myeloid leukemia (CML) who cannot undergo allogeneic bone marrow transplantation or failed to respond to recombinant alpha-interferon (IFN). In this review, we analyze the results which have been published for patients transplanted in chronic phase and which suggest that autografting could prolong survival, at least in some patients. We also discuss the different methods of purging whose clinical efficacy remains to be assessed.

Age-adapted induction treatment of acute lymphoblastic leukemia in the elderly and assessment of maintenance with interferon combined with chemotherapy. A multicentric prospective study in forty patients. French Group for Treatment of Adult Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) in the elderly is characterized by its poor prognosis. Forty patients with ALL, aged 55 years or older, and with good performance status (ECOG <3) were prospectively treated according to an age-adapted regimen: induction therapy was derived from the LALA87 protocol while the feasibility of treatment with interferon combined with chemotherapy was assessed during maintenance. Compared with younger adults treated according to the LALA87 protocol, elderly patients did not present with more adverse prognostic features, except for a lower incidence of T cell ALL (9 vs 31%, P=0.005). There were even less patients with a high leukocyte count (15 vs 38%, P=0.003), a characteristic associated with adverse prognosis while the incidence of Philadelphia-positive (Ph-positive) ALL was not significantly increased compared to younger adults (31 vs 20%, P=0.2). After completion of induction therapy, with or without salvage treatment, 85% (CI: 70-94%) obtained a complete response (CR) while treatment-related mortality during induction was 7.5% (CI: 2-20%). Median overall survival and disease-free survival were 14.3 months and 14 months, respectively, which, although inferior to results achieved in younger adults, compares favorably with available data in the elderly. Treatment with IFN proved feasible in most patients but had to be discontinued in eight patients because of toxicity. Age-adapted treatment improves the prognosis of ALL in the elderly even if, in most cases, a cure cannot be achieved.

Factors affecting both peripheral blood progenitor cell mobilization and hematopoietic recovery following autologous blood progenitor cell transplantation in multiple myeloma patients: a monocentric study.

The aim of the study was to analyze the factors influencing peripheral blood progenitor cell (PBPC) collection after high-dose cyclophosphamide (HDCYC) (7 g/m2) and hematopoietic recovery after autologous transplantation of HDCYC-mobilized PBPC (ABPCT) in 116 patients with aggressive multiple myeloma (MM). Following HDCYC 74 patients received hematopoietic growth factors (HGF), either G-CSF (n = 19) or GM-CSF (n = 55). All the patients were subsequently planned to undergo ABPCT. PBPC collection was possible for 106 patients. The most important prognostic factor for collection of more than 25 x 10(4) CFU-GM cells/kg and 2 x 10(6) CD34+ cells/kg was the use of HGF (P = 0.002 and 0.009, respectively). Previous use of an alkylating agent, response to treatment before HDCYC, and interval between diagnosis and HDCYC were also significant factors (P = 0.004, 0.025 and 0.001, respectively). The number of CFU-GM cells infused was the most important parameter for rapid and complete hematological recovery after ABPCT (P < 0.0001). Thus the use of HGF post-HDCYC is the major factor which, associated with reduced time between diagnosis and HDCYC and the use of an alkylating agent, could increase the numbers of hematopoietic progenitors collected, and subsequently improve hematopoietic recovery following ABPCT in MM patients.

Allogeneic vs autologous stem cell transplantation vs chemotherapy in patients with acute myeloid leukemia in first remission: the BGMT 87 study.

In 204 adult patients with de novo acute myeloid leukemia (AML), we prospectively compared allogeneic bone marrow transplantation (alloBMT), autologous stem cell transplantation (ASCT) and chemotherapy (Chemo). 162 patients (79.4%) achieved a complete remission (CR). Of the 135 patients who were still in CR after consolidation, 96 patients were less than 46 years of age: 36 patients had an HLA-identical sibling donor and were allocated for alloBMT (group I); they were compared to the 60 other patients who did not have an HLA-identical sibling donor and were treated with either ASCT or chemotherapy (group II). The 3-year disease-free survival was higher for group I patients (66.5 +/- 16%) than for the 60 group II patients (42.4 +/- 13%) (P < 0.05). The actuarial risk of relapse at 3 years was significantly lower for group I patients (24 +/- 15%) than for the other 60 group II patients (56 +/- 13%; P < 0.009). By multivariate analysis, the disease-free survival and risk of relapse were influenced by the initial WBC count (P < 0.02 and P < 0.006), the number of chemotherapy courses for CR (P < 0.001 and P < 0.01) and the type of post-induction treatment (alloBMT vs no alloBMT; P < 0.1 and P < 0.02). The 99 patients who did not fulfill the inclusion criteria for alloBMT were given intensive chemotherapy including high-dose aracytine. When they were still in CR (n = 77), these patients were then randomized for either ASCT (n = 39) or Chemo (n = 38). We were unable to detect any statistical difference between ASCT and Chemo for either disease-free survival, risk of relapse or survival. These results indicate that alloBMT seems to produce results which are at least superior to those of other therapeutic modalities. The results of either ASCT or Chemo look similar.

A prospective randomized trial of idarubicin vs daunorubicin in combination chemotherapy for acute myelogenous leukemia of the age group 55 to 75.

A prospective randomized study was conducted comparing the efficacy and toxicity of two anthracyclines for the treatment of patients with acute myeloid leukemia (AML) between 55 and 75 years. A total of 220 patients were randomized to receive as induction chemotherapy cytosine arabinoside (Ara-C: 100 mg/m2/day; continuous infusion for 7 days) combined with either daunorubicin (DNR: 50 mg/m2/day, i.v. bolus for 3 days) (n=108) or idarubicin (IDA: 8 mg/m2/day, i.v. bolus for 5 days) (n=112). The complete remission (CR) rate was similar (P=0.296) after IDA (76/112; 68%) and DNR (66/108; 61%) (P=0.3). For patients aged 55-65, the CR rate was significantly higher after IDA (39/47; 83%) than after DNR (29/50; 58%) (P=0.007). Persistent leukemia was more frequent after DNR (26/108) than after IDA (13/112; P=0.015). Hematological and extra-hematological toxicities were similar. The CR patients were given a consolidation course of chemotherapy with Ara-C: 50 mg/m2/12 h, subcutaneously for 5 days, combined with either DNR:30 mg m2/day, i.v. bolus for 3 days or IDA:8 mg/m2/day i.v. bolus for 3 days according to the initial randomization, and then received a continuous maintenance treatment for 2 years. The survival and disease-free survival (DFS) were similar in both groups; there was no difference in the risk of relapse. However, there was a trend for a longer event-free survival (EFS) in the IDA group than for the DNR patients (P=0.07). Our results seem to indicate that IDA is probably more efficient than DNR for AML patients between 55 and 75 years, and confirm the data published in other studies comparing prospectively IDA and DNR in adults.

Successful autologous transplantation with peripheral blood hemopoietic cells in a patient with acute leukemia.

One patient with acute nonlymphocytic leukemia (ANLL) in remission was given intensive chemotherapy (DAT regimen) as late intensification treatment. Seven leukaphereses were performed during the period of marrow recovery following aplasia induced by the DAT regimen. High numbers of nucleated cells (7.8 X 10(8)/kg) and granulocyte-macrophage precursors (9.5 X 10(4)/kg) were collected and then cryopreserved and stored in liquid nitrogen. When he relapsed, the patient was treated with etoposide (600 mg/m2), cyclophosphamide (120 mg/kg), and total body irradiation (1000 rad), followed by the transfusion of thawed autologous leukocytes. The time to reach 0.5 X 10(9) granulocytes/liter and 50 X 10(9) platelets/liter was 16 and 35 days, respectively. This observation demonstrates that circulating hemopoietic stem cells are capable of complete hemopoietic reconstitution after marrow-ablative therapy with supralethal doses of chemoradiotherapy.

Hydroxyurea versus interferon alfa-2b in chronic myelogenous leukaemia: preliminary results of an open French multicentre randomized study.

In order to compare the effects of interferon versus hydroxyurea for the treatment of chronic myelogenous leukaemia (CML), 58 CML patients, having received no previous treatment, were randomized into two treatment groups (hydroxyurea or interferon) for an open multicentre study from 1 May 1987 until 1 July 1990. Fifty patients were evaluable: 24 in the interferon group and 26 in the hydroxyurea group. Haematological response was obtained in 16/24 interferon-treated patients and 23/26 hydroxyurea patients. Failure to obtain haematological remissions occurred in eight of 24 interferon-treated patients and in three of 26 hydroxyurea patients. Four interferon-treated patient failures and one hydroxyurea-treated failure were due to drug intolerance. Progression occurred in one interferon-treated patient and in three patients given hydroxyurea. Fourteen of 16 patients in the interferon group and 17/23 in the hydroxyurea group continue on study and show no progression.

Place of low-dose total body irradiation in the treatment of localized follicular non-Hodgkin's lymphoma: results of a pilot study.

PURPOSE: In a first prospective nonrandomized trial, 107 patients with Stage III and IV "low-grade" lymphomas have been treated with a combination of chemotherapy and low-dose total body irradiation (LD-TBI). This study shows that this scheme of LD-TBI was very well tolerated, gave a high response rate (83%), and extended RFS. It incited us to start a pilot study on localized follicular lymphomas. METHODS AND MATERIALS: From January 1986 through October 1994, 34 patients with previously untreated localized low-grade non-Hodgkin's lymphomas have been included in a prospective trial with LD-TBI followed by radical involved field radiotherapy (IF-RT). Patients received two courses of whole body irradiation of 0.75 Gy in 5 fractions and 1 week separated by a rest period of 2 weeks. After 1 month, patients were reevaluated, and received 40 Gy in 20 fractions, and 4 weeks on initially pathological lymph node areas. Eight patients have been excluded from the study: 4 after histologic review (2 centrocytic, 1 lymphocytic, 1 centroblastic) and 4 patients with Stage IV because of bone-marrow involvement. The remaining 26 patients were 11 men and 15 women, 50 years old median age (mean: 50.2; range: 35-73.5) with clinical Stage I (10 pts), II1 (8 pts), and II2 (8 pts). All patients received the planned treatment. RESULTS: Clinical tolerance was excellent, and the hematological follow-up shows a mean nadir value of 3.9.10(9)/l (2.1-8.1) for leucocytes, 13.4 g/l (10.8-15.4) for hemoglobin, and 124.10(9)/l (46-216) for platelets, with a median delay of 3.2 months. Of 26 patients, 24 achieved complete remission (CR) after the LD-TBI that was before the IF-RT. All patients, except one, were in complete remission after IF-RT. Nineteen patients remain alive without any evidence of disease, with a median follow-up of 56.2 months. Five patients relapsed; 3 of them died. CONCLUSION: As delivered, this schedule of LD-TBI give a very high rate of CR in localized follicular non-Hodgkin's lymphoma, with a very good tolerance. It remains to prove that this immediate efficacy has an impact on long-term disease-free survival in such patients, and to understand how the LD-TBI works (direct and/or indirect induction of apoptosis; relationship with t(14;18) translocation and overexpression of bcl-2). These will be the two aims of a new EORTC prospective randomized trial comparing LD-TBI followed by IF-RT vs. IF-RT alone.

Platelet dense bodies loaded with mepacrine. Study in chronic idiopathic thrombocytopenic purpura (ITP).

In 22 cases of chronic ITP, the platelet 5-HT storage organelles were counted by examination of platelets loaded with mepacrine and correlated with the size and volume of the platelets. Statistical analysis showed that the mean volume and the number of granules increased in ITP without increase in the mean number of granules per unit volume. A strong correlation was found between platelet long diameter and number of dense bodies in controls (44 healthy subjects) (r = 0.94; y = 2.826 x - 0.699) and in ITP (r = 0.92; y = 2.587 x + 0.06). This study demonstrated in chronic ITP the presence both of platelets without granules and others rich in granules. The anomalies were present no matter what the count of platelets and did not change the mean values for granules and for ADP in most cases. Most platelets remain morphologically normal.

Acute promyelocytic leukemia with (15;17) translocation and chromosome no. 11 deletion (q23).

The patient, a 76-year-old man, was referred with fever, large ecchymotic lesions and ulcerative laryngitis. Blood counts showed a hemoglobin of 11 g/100 ml, hematocrit of 31%, red blood cell count of 3.5 X 10(12)/1, white blood cell count of 6.8 X 10(9)/1 and platelet count of 16.0 X 10(9)/1. The differential count showed 17% neutrophils, 4% lymphocytes, 40% promyelocytes and 39% myeloblasts. The sternal marrow sample showed a marked hypercellularity. Of the cells, 80-85% were hypergranular promyelocytes, some of them showing bundles of Auer rods. No granulocytic maturation was observed. A few erythroblasts were present. A disseminated intravascular coagulation was observed (fibrinogen 0.85 g/l, factor V 18%, fibrin degradation products 640 mg/l). The serum creatinin was at 217 micromol/1 and the urea at 16.8 mmol/1. The treatment (daunorubicin, heparin, platelet transfusion) was unsuccessful and the patient died three days after entering hospital. The bone marrow karyotype by direct examination showed only normal metaphases (32 photographed). All the metaphases from the unstimulated blood 48-h culture (25 photographed) were clonal, showing the pattern 47,XY,del(11) (q23),t(15;17) (q24? q22?), +mar. The marker was '16 like' in size but its origin could not be determined (Figs. 1 and 2).

Acute erythroblastic leukemia presenting as acute undifferentiated leukemia: a report of two cases with ultrastructural features.

This report describes two elderly patients with acute leukemia in which blast cells were undifferentiated with conventional light microscopy (L.M.) and cytochemistry. Blast cells were identified as belonging to the erythroblastic line by their ultrastructural features: glycogen deposits, lipidic vacuoles, cytoplasmic ferritin molecules and rhopheocytotic invagination. Moreover, blast cells were surrounding a central macrophage. Thus, these two patients had acute erythroblastic leukemia which differs from erythroleukemia (M6 of FAB classification) in which blast cells present myeloblastic characteristics.

Serial cytogenetic studies in allografted patients with chronic myeloid leukemia.

Serial marrow karyotyping was performed in 31 chronic myeloid leukemia (CML) patients treated with allogeneic bone marrow transplantation (BMT). Of 11 hematological relapses, seven were heralded for up to 20 months by a cytogenetic relapse (characterized by increasing percentages of Philadelphia (Ph)-positive metaphases, seen on serial karyotypes). Chromosomal abnormalities additional to the Ph, seen before BMT, were not found again at relapse. Relapses were characterized by clonal evolutions of the Ph-positive cells, likely corresponding to cytogenetic patterns of treatment-induced leukemia [del(5q), del(7q), complex karyotypes] and were different from those generally found in CML evolution. Involvement of chromosome 1 was also frequent. Sporadic Ph-positive metaphases (not seen in repeated karyotypes) were seen only during the first 8 months after BMT.

Mixed chimerism after sex-mismatched allogeneic BMT: evaluation of two molecular techniques.

Two different molecular techniques were used to monitor chimerism following 17 non-T cell-depleted BMTs from female donors to male recipients: pHY10, a Y chromosome-specific probe (Southern or slot blots), and a set of primers for Y chromosome sequence-specific amplification by the polymerase chain reaction (PCR). On Southern blots, male DNA was detectable at a level less than 1% of 10 micrograms DNA while cross-reactivity with autosomal sequences was avoided. On slot blots, male DNA was reliably detectable at levels less than 0.5%, even in small sample (0.5 microgram DNA). With the PCR technique, male DNA was detectable at levels of 1:10(6) to 1:10(7) of 0.5 microgram DNA. Slot blot and PCR results were concordant in 19 of 23 samples. Both techniques demonstrated a constant small mixed chimerism during the first year after BMT and in four of nine patients, this chimerism persisted even longer (up to 29 months after BMT).

High response rate using recombinant interferon-alpha in patients with newly diagnosed chronic myeloid leukemia.

To improve the management of chronic myeloid leukemia (CML) in a single center, we have used interferon-alpha (IFN-alpha) to treat newly diagnosed Ph-positive CML patients and investigated the factors predictive of a major cytogenetic response. Eighty-one patients with a median age of 50.5 y (17-70) were given IFN-alpha (5 x 10(6)/sqm/day, s.c.). The median interval between diagnosis and IFN-alpha was 45 days (0-160). IFN-alpha doses were adjusted to maintain the white blood cell (WBC) count between 1.5 and 5 x 10(9)/l and the platelet count between 50 and 100 x 10(9)/l. At diagnosis, Sokal's criteria were used to classify patients into three groups: low (n = 39), intermediate (n = 32) and high risk (n = 10). A complete hematological response (CHR) was achieved in 66 cases (81.5%). Cytogenetic response was evaluated in these 66 responders. Thirty-six patients (44.4%) achieved a major cytogenetic response (MCR) (> or = 65% Ph-negative cells), 31 of them having a complete cytogenetic response. The 5-y transformation-free survival (TFS) of the 81 patients was 77 +/- 14% (95% CI) and was statistically influenced by the CHR rate at three months (p = 0.008) and the achievement of MCR or CCR (p < 0.0009 and p < 0.0005, respectively). Moreover, we found that the MCR or CCR were significantly influenced by the obtaining of CHR at three months (p < 0.001 and p < 0.0001, respectively). These results show that IFN-alpha can induce high rates of hematological and cytogenetic responses when administered in doses leading to myelosuppression. The achievement of CHR within three months could be useful to identify early those patients who will not respond to IFN-alpha and who need alternative treatments such as allogeneic or autologous stem cell transplantation.