Progress in haematopoietic stem cell transplantation for multiple myeloma

High-dose myeloablative treatment followed by autologous haematopoietic stem cell transplantation has significantly improved survival of patients younger than 65 years of age with multiple myeloma as compared with conventional chemotherapy. However, all patients seem to relapse and molecular remissions are rare. Results of allogeneic transplantation, still hampered by high transplant-related mortality, have improved dramatically over the last 5-6 years and this is an option for patients younger than 50-55 years old. The relapse rate is lower than with autologous transplantation and molecular remissions are frequent. Some patients are still in complete haematological remission more the 10 years following transplantation. Autologous transplantation followed by nonmyeloablative allogeneic transplantation is on trial and may be a way to eventually cure a fraction of younger patients with multiple myeloma.     

Comparison of allogeneic or autologous bone marrow transplantation and chemotherapy in patients with acute myeloid leukaemia in first remission: a prospective controlled trial

Eighty-five adult patients under the age of 50 years with acute myeloid leukaemia (AML) were entered into a prospective controlled study conducted to compare the effectiveness of allogeneic or autologous bone marrow transplantation and intensive chemotherapy for patients in first complete remission. Sixty-one patients (72%) achieved complete remission then received a consolidation treatment. After consolidation, 58 patients who were still in remission were assigned to three different therapeutic modalities. Fifty-two patients were evaluable: 20 patients who had an HLA-identical sibling donor underwent allogeneic bone marrow transplantation within 3 months after achievement of complete remission; the other 32 patients were randomized to receive autologous bone marrow transplantation or intensive sequential chemotherapy. The actuarial risk of relapse at 3 years was 18% for the allogeneic patients, 50% for the autologous patients and 83% in the chemotherapy group. The difference was highly significant (P less than 0.0002). The disease-free survival was respectively 66% (95% confidence interval 41-85%), 41% (95% confidence interval 16-66%) and 16% (95% confidence interval 0-31%) (P less than 0.004). We conclude that allogeneic bone marrow transplantation is presently the best therapeutic approach for patients with AML in first complete remission.     

Allogeneic bone marrow transplantation versus autologous stem cell transplantation in multiple myeloma: a retrospective case-matched study from the European Group for Blood and Marrow Transplantation

A retrospective case-matched analysis was performed comparing 189 myeloma patients treated with allogeneic bone marrow transplantation (allo-BMT) with an equal number of patients who received autologous stem cell transplantation (ASCT). Matching was performed with respect to gender and number of treatment lines before transplantation. The groups were comparable with the exception of median age (43 years for allo-BMT v 49 years for ASCT, P = .0001) and median posttransplant follow-up (46 months for allo-BMT v 30 months for ASCT, P = .0003). The overall survival was significantly better for ASCT than for allo-BMT, with a median survival of 34 months and 18 months, respectively (P = .001). However, this survival advantage was only observed in men, but not in women. The statistically significant survival advantage for ASCT was seen in most subgroups, ie, chemotherapy-responsive patients, patients who had received two or more treatment lines before transplantation, patients in partial remission, patients with an IgG- subtype, patients older than 46 years of age, patients with stage II disease, and patients with a low or high serum-beta-2-microglobulin at diagnosis. The main reason for the poorer survival in allo-BMT patients was higher transplant-related mortality (41% v 13% for ASCT, P = .0001), which was not compensated for by a lower rate of relapse and progression. However, in patients alive at 1 year posttransplant, there was a trend for better long-term survival (P = .09) and significantly better progression-free survival (P = .02) for allo-BMT as compared with ASCT. We conclude that the median survival is superior for ASCT. However, allo-BMT has a lower relapse rate, which results in a similar long-term outcome for both approaches, but a longer follow-up is needed to assess the final outcome.     

Recent Developments in Hematopoietic Stem Cell Transplantation for Multiple Myeloma

Multiple myeloma (MM) is often successfully controlled with conventional chemotherapy; however, complete remissions are uncommon, and cure is rare. High-dose therapy followed by administration of autologous or allogeneic stem cells, used for the treatment of MM in the past 15 years, is promising as a means of increasing remission rates and improving survival. Autologous transplantation has not always demonstrated survival benefits in randomized studies because most of the patients receiving transplants have relapses, whereas patients given conventional therapy can receive salvage transplants when relapse occurs. Efforts to improve the results of autologous transplantation include targeted radiation, tandem transplantation, and posttransplantation immunotherapy. Only allogeneic hematopoietic stem cell transplantation is potentially curative, owing to a graft-versus-myeloma effect. Although patients who receive either allogeneic or autologous stem cell transplants for MM have similar 3- to 5-year survival rates, only allograft recipients appear to enjoy long-term disease-free survival. High transplantation-related mortality associated with allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative modality. Strategies designed to improve the therapeutic index of allografts include the use of nonablative conditioning regimens, peripheral blood cells rather than bone marrow, graft engineering, and targeted conditioning therapies, such as bone-seeking radioisotopes.     

Bone marrow transplantation for acute leukemia: recent advances and comparison with alternative therapies

Bone marrow transplantation is an effective therapy in patients with acute leukemia. High-dose chemotherapy with or without total body irradiation and allogeneic bone marrow transplantation is a more effective antileukemic treatment than chemotherapy. This approach is limited, however, by a relatively high risk of transplant-related complications, particularly graft rejection, GVHD, and interstitial pneumonitis. Autologous bone marrow transplantation avoids the problems of graft rejection and GVHD. It does, however, introduce a risk of reinfusing residual leukemia cells with the autologous bone marrow and absence of a possible graft-versus-leukemia effect associated with allogeneic transplants. Bone marrow transplantation is useful in AML. Syngeneic or allogeneic HLA-identical bone marrow transplantation is the preferred treatment for patients under age 45 to 50 who fail chemotherapy. Transplantation is also likely to be superior or comparable to chemotherapy for patients less than 20 to 30 years of age in first remission. Transplantation in older individuals in first remission is controversial; results are comparable to those achieved with postremission chemotherapy. Transplants from donors other than HLA-identical siblings must be considered investigational but may be a reasonable alternative in young individuals in first relapse or second remission. Autotransplants are difficult to evaluate critically but may be considered as investigational therapy for individuals in second or later remission for whom a suitable allogeneic donor is unavailable. Autotransplants in first remission should be restricted to controlled clinical trials because it is otherwise impossible to determine their efficacy. It is uncertain whether ex vivo treatment of the bone marrow to remove leukemia cells is necessary in the context of autotransplantation; again, controlled trials are required. Bone marrow transplantation from an HLA-identical sibling is effective in individuals with ALL who relapse despite chemotherapy. Patients undergoing transplantation while in second or later remission or in relapse have a survival rate superior to those treated with chemotherapy. One important and unresolved issue is whether patients with high-risk ALL should receive bone marrow transplants or intensive postremission chemotherapy while in first remission; controlled clinical trials are needed. Bone marrow transplants from donors other than HLA-identical siblings and autologous bone marrow transplants are investigational approaches that should be considered in selected young patients who fail despite chemotherapy.(ABSTRACT TRUNCATED AT 400 WORDS)     

Aggressive chemotherapy for acute leukemia relapsed after bone marrow transplantation: a second chance?

Eight patients, 5 with acute non lymphoid leukemia and 3 with lymphoid leukemia, were treated at relapse after bone marrow transplantation (BMT; 4 autologous BMT and 4 allogeneic BMT). Of these, 2 relapsed within 3 months after BMT (2 allogeneic BMT) and 6 (2 allogeneic and 4 autologous BMT) after more than 9 months after BMT. The 2 patients relapsing early showed no response to treatment and died. Five out of 6 patients relapsing late achieved complete remission (4 of them with intensive chemotherapy). Four patients are currently alive. Aggressive combination chemotherapy can produce long-term survival in selected patients relapsed after BMT.     

Hematopoietic stem cell transplantation for de novo acute megakaryocytic leukemia in first complete remission: a retrospective study of the European Group for Blood and Marrow Transplantation (EBMT)

Acute megakaryoblastic leukemia (M7 AML) is a highly aggressive disease. We evaluated outcomes in 57 children (11 with Down syndrome) and 69 adults with M7 AML after first complete remission (CR1) following autologous or HLA-identical allogeneic transplantation. Characteristics of the recipients of autologous transplants (38 children, 37 adults) were, respectively: median age, 1.7 and 46 years; non-total body irradiation (non-TBI) conditioning regimen, 97% and 70%; bone marrow as stem cell source, 74% and 43%. Characteristics of the recipients of allogeneic transplants (19 children, 32 adults) were, respectively: median age, 2.8 and 37 years; non-TBI regimen, 63% and 42%; bone marrow as stem cell source, 95% and 69%. Autologous transplantation benefited children more; the relapse rate was high in adults. Results for autologous transplantation were (children and adults, respectively): engraftment, 90% and 100%; 3-year treatment-related mortality (TRM) rate, 3% and 8%; relapse rate, 45% and 64%; leukemia-free survival (LFS) rate, 52% and 27%; overall survival (OS) rate, 61% and 30%. After allogeneic transplantation, TRM was fairly low in children and adults, and relapse rates were lower than after autologous transplantation. Results for allogeneic transplantation were, respectively: engraftment, 95% and 90%; TRM, 0% and 26%; relapse rate, 34% and 28%; LFS, 66% and 46%; OS, 82% and 43%). We conclude that M7 AML patients in CR1 (except children with Down syndrome, who already have better outcomes) can benefit from transplantation.     

European Group for Blood and Marrow Transplantation Registry studies in multiple myeloma

The European Group for Blood and Marrow Transplantation (EBMT) Myeloma Registry, established in 1987, contains data on 1,368 allogeneic and more than 8,000 autologous stem cell transplants performed since 1983. Among autologous transplant patients, the median survival after transplantation is 50 months, and the actuarial survival at 10 years is 30%, with a plateau appearing at about 8 years. Factors of importance for a more favorable prognosis are lower age, response to chemotherapy, only one course of primary chemotherapy, stage I or II disease, and low beta(2)-microglobulin at diagnosis. Beneficial procedural factors associated with better outcome are a preparative regimen without total body irradiation (TBI), posttransplant interferon alfa maintenance treatment, and possibly tandem transplantation. In vitro graft purging, using CD34(+) selection, does not have any impact on survival. A case-matched analysis comparing autologous and allogeneic transplantation demonstrated significantly better survival in the former group, with median posttransplant survival times of 36 months and 18 months in the autologous and allogeneic groups, respectively. This result was in turn due to a markedly lower incidence of transplant-related death among the autotransplant patients: 13%, versus 41% for the allogeneic group. However, recent data on allogeneic transplants performed from 1994 to 1998 has demonstrated a decrease in treatment-mortality to 30%, and this has resulted in a prolongation of survival; in this analysis, the results are similar irrespective of the type of graft used, allogeneic bone marrow or blood stem cells. In a small case-matched analysis, transplantation with an identical twin donor was superior to both allogeneic and autologous transplantation with respect to survival and freedom from progression.     

Intensive cytotoxic therapy followed by autologous bone marrow transplantation for non-Hodgkin's lymphoma of high-grade malignancy

Fourteen patients with non-Hodgkin's lymphoma (NHL) of high-grade malignancy were treated with cyclophosphamide and total body irradiation followed by autologous bone marrow transplantation (ABMT). All patients were pretreated with conventional chemotherapy. Three of four patients with drug-resistant disease achieved complete remission (CR), but relapse occurred within six months. Four patients in partial remission (PR) achieved CR; one died because of sepsis, two relapsed within six months, and one is still in CR 28+ months later. Six were treated in CR, five in first CR, and one in second CR. From these six patients (who received this treatment as consolidation therapy), five are in unmaintained CR seven to 31+ months after ABMT (one patient died of a secondary illness). There were two therapy-related deaths, both in patients with a poor clinical condition. Toxicity of this treatment was mild for those receiving transplants who were in better condition. These preliminary results suggest that intensive cytoreductive therapy followed by ABMT may improve disease-free survival in patients in NHL of high-grade malignancy in CR.     

Treatment of peripheral T-cell lymphomas (PTCL) with high-dose chemotherapy and autologous or allogeneic hematopoietic transplantation

Peripheral T-cell lymphomas (PTCL) are a rare entity of non-Hodgkin's lymphomas (NHL). Despite the poor outcome after conventional chemotherapy, the impact of high-dose chemotherapy (HDCT) and autologous or allogeneic stem cell transplantation is not well defined in these patients. In a retrospective study, we evaluated the outcome of 15 patients (9 male, 6 female) with PTCL after HDCT with autologous (10 patients) and allogeneic (5 patients) stem cell transplantation between 1996 and 2001 at our department. At the time of transplantation three patients were in second remission, seven patients were in partial remission (PR), and three patients had refractory disease. Two patients were treated with sequential HDCT (cyclophosphamide, adriamycin, vincristine, etoposide, prednisolone, m-CHOEP). The conditioning regimes were heterogeneous. After HDCT ten patients (67%, autologous 7, allogeneic 3) achieved CR, two patients (13%, autologous 2, allogeneic 0) had refractory disease, and three patients (20%, autologous 1, allogeneic 2) died because of toxic side effects before evaluation of response was performed. The median overall survival (OS) was 12 months. The 1-year probability of survival for the autologous and allogeneic groups was 58% and 40%, respectively. At the time of evaluation, six patients are alive and nine patients have died (four severe infection, one late toxicity, two disease progression, and two relapse). Despite the small number of patients in this study, HDCT with autologous or allogeneic hematopoietic transplantation seems to be an effective treatment option that can achieve CR for patients with PTCL. Because of the poor outcome of these patients after conventional chemotherapy, HDCT seems to be a rational option in first-line therapy. Whether it improves survival in these patients should be further investigated.     

Bortezomib plus dexamethasone treatment followed by reduced-intensity allogeneic stem cell transplantation for multiple myeloma refractory to high-dose chemotherapy with autologous transplantation

We present two long-term survivors after allogeneic transplantation with reduced-intensity conditioning regimen following relapse after autologous stem cell transplantation (ASCT) for multiple myeloma (MM). The first case was a 47-year-old male with IgG MM treated with 2 courses of high-dose melphalan along with ASCT and thalidomide, resulting in a minimal response. He then received 2 courses of bortezomib plus dexamethasone (BD) regimen, which was discontinued due to peripheral neuropathy. Allogeneic peripheral stem cell transplantation (PBSCT) from a sibling donor was performed after pretreatment with fludarabin (125 mg/m(2)) and melphalan (100 mg/m(2)). Engraftment was observed on day 11 and monoclonal IgG had disappeared 5 months after transplantation. The patient has been in complete remission for more than two and a half years with moderate chronic graft-versus-host disease (GVHD). The second case was a 51-year-old male who relapsed after ASCT for IgA MM. After 3 courses of BD treatment, irradiation to lumbar plasmacytoma, and thalidomide therapy, he received allogeneic PBSCT from a related donor after the same reduced intensity conditioning as performed in case 1. A complete response was observed 6 months after PBSCT. The patient has remained relapse-free for two years without GVHD. BD treatment followed by allogeneic stem cell transplantation with reduced intensity conditioning is supposed to be one of the most powerful strategies for patients showing relapse after ASCT.     

Outcome after autologous and allogeneic stem cell transplantation for patients with multiple myeloma: impact of graft-versus-myeloma effect

A total of 228 patients with multiple myeloma (MM), 166 patients receiving autologous transplantation (124 PBSC and 38 BM) and 66 patients receiving T-cell-depleted allogeneic transplantation were analyzed to compare overall survival (OS), progression-free survival (PFS) and risk of relapse. Patients receiving autologous transplantation had a significantly improved OS (P=0.006) and PFS (P=0.002) at 2 years with OS and PFS for autologous transplant 74% and 48%, respectively, compared with 51% and 28% for allogeneic transplantation. By 4 years after transplantation, outcome was similar with OS and PFS for autologous transplantation 41% and 23%, respectively, compared with 39% and 18% for allogeneic transplantation. The 4-year cumulative incidence of nonrelapse mortality was significantly higher in patients receiving allogeneic transplantation (24% vs 13%) (P=0.004). Relapse was the principle cause of treatment failure for both groups; however, there was a significantly reduced risk of relapse associated with allogeneic transplantation at 4 years: 46% for allograft vs 56% for autograft (P=0.02). Despite a lower risk of relapse after allogeneic transplantation, autologous transplantation is associated with improved OS and PFS compared with allogeneic transplantation in patients with MM. Strategies focused on reducing nonrelapse mortality in allogeneic transplantation may translate into an improved outcome for patients receiving allogeneic transplantation.     

Allogeneic bone marrow transplantation for patients with acute nonlymphocytic leukemia

Seventy patients with acute nonlymphocytic leukemia (ANLL) underwent allogeneic bone marrow transplantation following cytoreduction with total body irradiation and cyclophosphamide. Thirty patients underwent transplantation in first remission, 11 in second remission, 3 in third remission, and 26 in relapse. At a median follow-up of 30 mo, 17 of those in first remission and 7 of those in second remission survive in continuous remission, compared to 1 in third remission and 3 in relapse. The 3-yr Kaplan-Meier probability of disease-free survival among the various groups was 55% (+/- 9.2%) for the first remission transplants, 64% (+/- 14.5%) for second remission, 33% (+/- 20%) in third remission, and 10.3% (+/- 6.3%) in the relapse group. Statistical analysis showed a similar survival in the first and second remission groups that was significantly better than that seen in the third remission and relapse groups (p less than 0.01). The improved survival seen in the early remission groups was due to a significant decrease in the incidence of relapse posttransplant (p less than 0.01). These results confirm observations that a significant number of patients transplanted in first remission may achieve extended disease-free survival and document similar results for patients transplanted in second remission.     

Single-centre experience with nonmyeloablative allogeneic stem cell transplantation in patients with multiple myeloma: prolonged remissions induced

BACKGROUND: The role of allogeneic stem cell transplantation in multiple myeloma is not yet established. METHODS: We retrospectively evaluated the outcome of nonmyeloablative allogeneic stem cell transplantation (NMA) in patients with multiple myeloma treated at the Department of Haematology of the University Medical Centre Utrecht. Thirty-six patients received NMA as part of the first-line treatment; 23 patients as part of salvage therapy. Conditioning regimen was low-dose total body irradiation (TBI, 2 Grays) only; fludarabine was added in patients without previous autologous stem cell transplantation and patients with matched unrelated donors received antithymocyte globulin in addition to fludarabine and TBI. RESULTS: Following NMA overall response increased from 84 to 90%, complete remission rate from 15 to 32%. As part of first-line treatment NMA induced complete remission in 50% of patients vs one patient (4%) treated for relapsed multiple myeloma. Median progression-free survival was 26 months (13 months for the salvage group, 38 months for the 'upfront' patients). Median overall survival has not been reached yet. The achievement of complete remission following NMA as part of first-line treatment was associated with prolonged progression-free and overall survival. Major toxicities were acute and chronic graft-vs-host disease occurring in 64% (23% grade 3-4) and in 54% (49% extensive) patients, respectively. Seven patients (12%) died from nonrelapse mortality, five patients (9%) directly related to toxicity of NMA. CONCLUSION: NMA in multiple myeloma is feasible, is associated with acceptable nonrelapse mortality and may induce prolonged complete remission. In pretreated patients the result of NMA is disappointing which urges new strategies.     

Allogeneic hematopoietic stem cell transplantation in patients with diffuse large B cell lymphoma relapsed after autologous stem cell transplantation: A GITMO study

Patients who relapse after an autologous hematopoietic stem cell transplantation (SCT) have a very poor prognosis. We have retrospectively analyzed diffuse large B cell lymphoma patients who underwent an allo-SCT after an auto-SCT relapse reported in the Gruppo Italiano Trapianto di Midollo Osseo (GITMO) database. From 1995 to 2008, 3449 autologous transplants were reported in the GITMO database. Eight hundred eighty-four patients relapsed or progressed after transplant; 165 patients, 19% of the relapsed patients, were treated with allo-transplant. The stem cell donor was related to the patient in 108 cases. A reduced intensity conditioning regimen was used in 116. After allo-SCT, 72 patients (43%) obtained a complete response and 9 obtained a partial response with an overall response rate of 49%; 84 patients (51%) experienced rapid progression of disease. Ninety-one patients died, 45 due to disease and 46 due to treatment-related mortality. Acute graft-versus-host disease was recorded in 57 patients and a chronic GvHD in 38 patients. With a median follow-up of 24 months (2-144) after allo, overall survival (OS) was 39%, and after a median of 21 months (2-138) after allo, progression-free survival (PFS) was 32%. Multivariate analysis indicated that the only factors affecting OS were status at allo-SCT, and those affecting PFS were status at allo-SCT and stem cell donor. This retrospective analysis shows that about one-fifth of patients with diffuse large B cell lymphoma who experience relapse after autologous transplantation may be treated with allogeneic transplantation. Moreover, the only parameter affecting either OS or PFS was the response status at the time of allo-SCT.     

Allogeneic hematopoietic cell transplantation for multiple myeloma

Some patients with multiple myeloma (MM) who have undergone allogeneic hematopoietic stem cell transplants remain free of disease 5 to 13 years later-a major accomplishment for a malignancy that had been resistant to all investigational therapies. Although it will require longer follow-up to determine how many are truly cured, results for patients with MM transplanted from identical twins suggest that long-term progression-free survival is possible. While 3- to 5-year survival is similar after allogeneic or autologous stem cell transplant for MM, only allograft recipients appear to enjoy long-term disease-free survival, most likely due to an allogeneic graft-versus-myeloma (GVM) effect. The very high transplant-related mortality associated with standard allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative treatment. The challenge for clinical investigators will be to reduce the incidence of posttransplant complications. Strategies include the use of nonablative conditioning for allografts, the administration of peripheral blood stem cells (PBSC) rather than bone marrow, and the application of more focused, targeted conditioning therapies such as bone-seeking radioisotopes.     

Early recurrence of rheumatoid arthritis after nonmyeloablative allogeneic blood stem cell transplantation in a patient with multiple myeloma

Allogeneic blood stem cell transplantation with reduced conditioning has been proposed as a new, potentially curative treatment option for patients with rheumatoid arthritis (RA). We report a 60-year-old woman with RA and coexisting multiple myeloma who was treated with high-dose melphalan and autologous blood stem cell transplantation (BSCT) followed by a nonmyeloablative allogeneic BSCT from her healthy dizygotic twin brother. She achieved a complete remission of her RA after autologous BSCT, but relapsed early despite complete donor chimerism following successful allogeneic transplantation with reduced intensity conditioning. This case illustrates that allogeneic BSCT following nonmyeloablative conditioning may be an uncertain option for curing patients with RA.     

High-dose cytosine arabinoside and fractionated total-body irradiation: an improved preparative regimen for bone marrow transplantation of children with acute lymphoblastic leukemia in remission

Twenty children with acute lymphoblastic leukemia in second (18 patients) or third (two patients) complete remission after bone marrow relapse received allogeneic bone marrow transplants from histocompatible sibling donors. The preparative regimen for marrow transplantation consisted of 12 doses of 3,000 mg/m2 cytosine arabinoside twice daily for six days followed by 1,200 cGy total-body irradiation (six doses of 200 cGy twice daily for three days). The preparative regimen was well tolerated, and all patients showed marrow engraftment promptly. Twelve patients are alive in complete remission 12+ to 79+ months posttransplant; eight patients are over 48 months posttransplant. Six patients died 1 to 9 months posttransplant of nonleukemic causes: (two each of graft-v-host disease, interstitial pneumonitis, and infection). Two patients developed recurrent leukemia at 15 and 30 months posttransplant. Both have died at 19 and 36 months posttransplant. Life table analysis reveals an actuarial survival and event-free survival rate of 58% and a marrow relapse rate of 17%. These results suggest that high-dose cytosine arabinoside and fractionated total-body irradiation is a relatively nontoxic and highly effective preparative regimen for allogeneic bone marrow transplantation for acute lymphoblastic leukemia that deserves further evaluation.     

Graft-versus-leukemia reactions after bone marrow transplantation

To determine whether graft-versus-leukemia (GVL) reactions are important in preventing leukemia recurrence after bone marrow transplantation, we studied 2,254 persons receiving HLA-identical sibling bone marrow transplants for acute myelogenous leukemia (AML) in first remission, acute lymphoblastic leukemia (ALL) in first remission, and chronic myelogenous leukemia (CML) in first chronic phase. Four groups were investigated in detail: recipients of non--T-cell depleted allografts without graft-versus-host disease (GVHD), recipients of non-- T-cell depleted allografts with GVHD, recipients of T-cell depleted allografts, and recipients of genetically identical twin transplants. Decreased relapse was observed in recipients of non--T-cell depleted allografts with acute (relative risk 0.68, P = .03), chronic (relative risk 0.43, P = .01), and both acute and chronic GVDH (relative risk 0.33, P = .0001) as compared with recipients of non--T-cell depleted allografts without GVHD. These data support an antileukemia effect of GVHD. AML patients who received identical twin transplants had an increased probability of relapse (relative risk 2.58, P = .008) compared with allograft recipients without GVHD. These data support an antileukemia effect of allogeneic grafts independent of GVHD. CML patients who received T-cell depleted transplants with or without GVHD had higher probabilities of relapse (relative risks 4.45 and 6.91, respectively, P = .0001) than recipients of non--T-cell depleted allografts without GVHD. These data support an antileukemia effect independent of GVHD that is altered by T-cell depletion. These results explain the efficacy of allogeneic bone marrow transplantation in eradicating leukemia, provide evidence for a role of the immune system in controlling human cancers, and suggest future directions to improve leukemia therapy.     

Unrelated donor or autologous marrow transplantation for treatment of acute leukemia

High-dose chemoradiotherapy followed by marrow transplantation from an HLA-matched sibling donor is curative for patients with acute leukemia. Autologous marrow transplantation has been used with success for some patients without such a sibling. Alternatively, the option of performing a transplant from an HLA-matched unrelated donor has been made possible by the recent development of large registries of HLA- typed volunteers. The purpose of this study was to compare the outcomes for patients with advanced leukemia treated by unrelated or autologous marrow transplantation. Forty-three patients with acute myeloid or lymphoid leukemia were transplanted from a closely HLA-matched unrelated donor. Results were compared with those of a disease-, disease-stage-, and age-matched cohort of 77 patients treated with autologous marrow transplantation at the same institution during the same period. Myeloid reconstitution with peripheral granulocyte counts greater than 10(9)/L was achieved in 93% of unrelated recipients and 70% of autologous recipients at a median of 24 and 36 days after transplantation, respectively (P = .0001). The cumulative proportions of patients discharged alive (79% v 77%) and times from transplant to first hospital discharge (35 v 34 days) were not different between unrelated and autologous recipients (P = .65). For patients transplanted in complete remission, relapse occurred after transplantation in 27% of the unrelated and in 55% of the autologous recipients (P = .08). For patients transplanted in relapse, the corresponding posttransplant relapse rates were 48% and 63%, respectively (P = .72). Forty percent of unrelated recipients and 28% of autologous recipients died in remission. Leukemia-free survivals were 33% for unrelated and 25% for autologous recipients transplanted in remission (P = .45), and 12% for unrelated and 5% for autologous recipients transplanted in relapse (P = .75). Unrelated donor transplants appear no less effective than autologous transplants to achieve long-term survival and may be more effective in eradicating leukemia in patients who have failed conventional chemotherapy. Further studies are warranted to assess the relative effectiveness of unrelated and autologous transplantation performed earlier in the course of the disease.