Allogeneic bone marrow transplantation for poor-prognosis lymphoma: response, toxicity and survival depend on disease histology

Allogeneic hematopoietic stem cell transplant for relapsed and refractory non-Hodgkin lymphoma in pediatric patients

Allogeneic hematopoietic stem cell transplant (HSCT) for relapsed pediatric non-Hodgkin lymphoma (NHL) is often reserved for patients with certain NHL subtypes or high-risk disease whereas the remainder receive autologous HSCT. Given the aggressive nature of pediatric NHL, we performed allogeneic HSCTs for all patients regardless of disease risk. We report overall survival (OS) and prognostic variables in 36 pediatric patients who underwent allogeneic HSCT between 1998 and 2016. OS at 3 years was 67%. The 3-year OS varied based on NHL subtype: 100% for anaplastic large cell lymphoma (n = 14), 63% for diffuse large B-cell lymphoma (n = 8), 17% for lymphoblastic lymphoma (LL; n = 9) and 80% for other subtypes combined (n = 5). Disease status influenced outcome with 3-year OS of 100% for patients in complete remission (n = 15), 59% with partial remission (PR; n = 17), and 0% with progressive/stable disease (n = 3) (P = .004). Of the 17 patients in PR, all 6 with LL died of relapsed disease, whereas the other 11 attained remission after HSCT and remained disease-free. The cumulative incidence of relapse after HSCT for LL was 78% compared with 15% for all other NHL subtypes combined (P < .0001). Cumulative incidence of nonrelapse mortality (NRM) was low in our cohort at 6%. Hence, allogeneic HSCT is a well-tolerated and useful therapeutic option with low rates of NRM and relapse for all NHL subtypes except LL with active disease at HSCT.

Clinical Outcomes after Allogeneic Stem Cell Transplantation for Adult Lymphoblastic Lymphoma

Lymphoblastic lymphoma (LBL) is a rare subtype of non-Hodgkin lymphoma. There are limited reports on allogeneic stem cell transplantation (allo-SCT) in patients with LBL. We retrospectively analyzed the clinical outcomes of 15 adult patients with LBL who received allo-SCT at our institution. The median age at allo-SCT was 29 years (range, 18-42). Disease status at the time of transplantation was complete remission (CR), partial remission (PR), and advanced disease in 4, 4, and 7 patients, respectively. The median follow-up duration of survivors was 25 months (range, 6-106). The probabilities of overall survival (OS) and progression-free survival (PFS) at 2 years after allo-SCT were 37% and 24%, respectively. The respective 2-year OS and PFS rates of the 8 patients with CR or PR at the time of transplantation were 57% and 45%, while those with advanced disease were 14% and 0%. In conclusion, the treatment outcomes of allo-SCT in patients with LBL were unsatisfactory. Although outcomes were promising in patients with CR or PR at the time of transplantation, they were dismal in patients with progressive disease. Further advances in chemotherapy, both induction and salvage therapies, are needed to improve the clinical outcomes of patients with LBL.

Anti-thymocyte globulin could improve the outcome of allogeneic hematopoietic stem cell transplantation in patients with highly aggressive T-cell tumors

The early experiment result in our hospital showed that anti-thymocyte globulin (ATG) inhibited the proliferation of lymphoid tumor cells in the T-cell tumors. We used the ATG as the part of the conditioning regimen and to evaluate the long-term anti-leukemia effect, the safety and complication in the patients with highly aggressive T-cell lymphomas. Twenty-three patients were enrolled into this study. At the time of transplant, six patients reached first or subsequent complete response, three patients had a partial remission and 14 patients had relapsed or primary refractory disease. The conditioning regimen consisted of ATG, total body irradiation, toposide and cyclophosphamide. The complete remission rate after transplant was 95.7%. At a median follow-up time of 25 months, 16 (69.6%) patients are alive and free from diseases, including nine patients in refractory and progressive disease. Seven patients died after transplant, five from relapse and two from treatment-related complications. The incidence of grades II–IV acute graft-vs-host disease (GvHD) was 39.1%. The maximum cumulative incidence of chronic GvHD was 30%. The most frequent and severe conditioning-related toxicities observed in 8 out of 23 patients were grades III/IV infections during cytopenia. Thus, ATG-based conditioning is a feasible and effective alternative for patients with highly aggressive T-cell tumors.

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.

Stem cell transplantation for indolent lymphoma: a reappraisal

Allogeneic transplantation is established as a curative treatment for follicular lymphoma, but with considerable short and long-term morbidity and mortality. Data and controversies regarding conditioning regimen, donor source, GVHD prophylaxis, post transplant interventions and approaches to predict and reduce morbidity and mortality are reviewed. Total body irradiation is very effective but toxic and reduced intensity conditioning is often preferred though associated with somewhat higher rates of recurrence. The risk of chronic GVHD and its late sequelae can be markedly reduced by in-vivo T-cell depletion using alemtuzumab but also leads to somewhat higher incidence of disease recurrence. When using such treatment strategies, one can consider prophylactic or preemptive donor lymphocyte infusions or low toxicity medical treatment such as rituximab. Overall the long term outcomes, particularly survival and current progression free survival of patients undergoing allogeneic transplantation for indolent lymphoma have steadily improved and transplant can now often safely be considered up to the sixth decade of life. Outcomes of unrelated donor transplantation approach those of HLA-identical sibling transplant and even mismatched umbilical cord transplant can be considered in selected patients. The assessment of risks and benefits is aided by the use of various novel tools.

Current status of allogeneic transplantation for aggressive non-Hodgkin lymphoma

PURPOSE OF REVIEW

To provide a succinct update on the role of allogeneic stem cell transplantation (allo-SCT) in the management of patients with aggressive lymphomas. To clarify the indications for allogeneic transplantation vis-à-vis autologous transplant and to discuss the rationale and potential benefits of reduced intensity conditioning (RIC), nonmyeloablative (NMA) transplant, T-cell depletion and variations in graft vs. host disease (GVHD) prophylaxis.

RECENT FINDINGS

Considerable effort has been spent in developing transplant regimens with reduced toxicity and reduced GVHD. The role of allogeneic transplantation has also been redefined in light of advances in lymphoma classification, diagnostic methods, particularly PET scan and advances in transplant technology. Haplo and umbilical cord blood SCT allow identification of a donor for nearly all patients.

SUMMARY

In diffuse large B-cell lymphoma, the outcome of allo-SCT depends on patient characteristics and chemosensitivity. It is useful after failure of auto-SCT and in partial responses to salvage therapy. Allo-SCT may be the treatment of choice for advanced T-cell and natural killer cell lymphoma and for adult T-cell leukemia-lymphoma. Prophylactic or preemptive donor lymphocyte infusion may be useful, but requires controlled studies. RIC and NMA conditioning have reduced early toxicity but are associated with increased risk for disease recurrence. Promising data have been reported from a novel conditioning regimen combining NMA with ibritumomab tiuxetan. T-cell depletion reduces chronic GVHD but has some increase in rate of recurrence. Rapamycin may be associated with reduction in risk for disease recurrence.

MTX or mycophenolate mofetil with CsA as GVHD prophylaxis after reduced-intensity conditioning PBSCT from HLA-identical siblings

Mycophenolate mofetil (MMF) in combination with CsA seems to lead to earlier post transplant hematological recovery and less mucositis than MTX, with a similar incidence of GVHD. In this study we analyzed the post transplant outcomes of two cohorts of patients who underwent an HLA-identical sibling reduced intensity conditioning transplantation (allo-RIC) with GVHD prophylaxis consisting of CsA in combination with either MMF or a short course of MTX. We included 145 consecutive allo-RIC transplants performed between April 2000 and August 2007. The median follow-up for survivors was 41 months (4-105 months). The study group included 91 males. Median age was 55 years (range 18-71 years). Diagnoses included myeloid (n=65) and lymphoid (n=80) malignancies. GVHD prophylaxis consisted of CsA/MMF in 52 and CsA/MTX in 93 patients. The conditioning regimen was based on fludarabine in combination with BU (n=59) or melphalan (n=86). The occurrence of grade 2-4 mucositis was higher in the CsA/MTX group than in the CsA/MMF group (57 vs 23%, P=0.001). The cumulative incidence of acute and chronic GVHD was similar, 48 vs 50% and 71 vs 68%, respectively (P>0.7). The 2-year relapse and OS were similar in the CsA/MTX and CsA/MMF groups (29 vs 21%, P=0.3 and 52 vs 51%, P=0.7, respectively). Our results support further prospective studies comparing the use of the CsA/MMF combination with CsA/MTX as GVHD prophylaxis in HLA-identical sibling donor allo-RIC recipients.

Enteropathy associated T-cell lymphoma and its precursor lesions

Enteropathy Associated T-cell Lymphoma (EATL) is an intestinal tumour of intra-epithelial lymphocytes. Based on morphology, immunohistochemistry and genetic profile EATL can be divided into two groups. EATL type I is a large cell lymphoma which is highly associated with Coeliac Disease (CD) and mostly presents with malabsorption, weight loss and CD-related symptoms. EATL type II consists of small to medium-sized cells and presents often with obstruction or perforation of the small bowel. This type of EATL has no known association with CD. When EATL has been diagnosed a thorough diagnostic work-up is needed. This work-up preferably includes video capsule enteroscopy (VCE), double-balloon enteroscopy (DBE), computed tomography (CT) combined with 18F-fluorodeoxyglucose positron emission tomography scan (18F-FDG-PET scan) if possible and magnetic resonance enteroclysis (MRE). Nowadays, most EATL patients are treated with chemotherapy mostly preceded by resection of the tumour and followed by stem cell transplantation. Despite these therapies outcome of EATL remains very poor with a 5-year survival of 8-20%. In order to improve survival prospective multicentre trials, studying new therapies are needed. The combination of chemotherapy, monoclonal antibodies and/or apoptosis inducing small molecules might be a potential treatment for EATL in the (nearby) future.

Assessment of the hematopoietic cell transplantation comorbidity index in non-Hodgkin lymphoma patients receiving reduced-intensity allogeneic hematopoietic stem cell transplantation

The hematopoietic cell transplantation comorbidity index (HCT-CI), a weighted index of 17 pretransplantation comorbidities, has been validated in nonmyeloablative and myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) studies, but it has not been specifically tested in patients with non-Hodgkin lymphoma (NHL) receiving reduced-intensity conditioning (RIC). We performed a retrospective analysis to assess the impact of the HCT-CI on outcomes of NHL patients treated with HSCT relative to treatment-related mortality (TRM), disease-related mortality (DRM), with a specific emphasis on overall survival (OS). Individual pretransplantation and disease-related factors also were analyzed with HCT-CI relative to their impact on OS. All patients were uniformly treated with an identical pretransplantation induction regimen and an identical RIC regimen (cyclophosphamide [Cy]/fludarabine [Flu]), and received T cell-replete allografts from HLA-matched siblings. The analysis included 63 NHL patients with a median HCT-CI score of 2 (range, 0 to 11). The HCT-CI (0 to 2 comorbidities vs 3+ comorbidities) demonstrated a potential association with TRM, but not with DRM, at 100 days (4.5% vs 26.3%) and at 1 year (13.6% vs 36.8%) posttransplantation. The factor most strongly associated with OS was response to pretransplantation chemotherapy (P= .0001), based on a composite measure. In a Cox model, pretransplantation chemotherapy response remained the most important factor (P< .0001) relative to OS, and there was a trend (P= .056) toward HCT-CI adding predictive value for OS. Although HCT-CI may be useful for predicting TRM, our data further underscore the importance of response to chemotherapy before transplantation as a predictor of overall transplantation outcome in NHL patients being considered for RIC allogeneic HSCT.

Unrelated donor hematopoietic cell transplantation for non-hodgkin lymphoma: long-term outcomes

We analyzed the outcomes of 283 patients receiving unrelated donor allogeneic hematopoietic cell transplantation for non-Hodgkin lymphoma (NHL) facilitated by the Center for International Blood and Marrow Transplant Research/National Marrow Donor Program (CIBMTR/NMDP) between 1991 and 2004. All patients received myeloablative conditioning regimens. The median follow-up of survivors is 5 years. Seventy-three (26%) patients are alive. The day 100 probability of death from all causes is estimated at 39%. The cumulative incidence of developing grade III-IV acute graft-versus-host disease (aGVHD) at day 100 is 25%. The estimated 5-year survival and failure free survival are 24% (95% confidence interval [CI]: 19-30) and 22% (95% CI: 17-28), respectively. Factors adversely associated with overall survival (OS) included increasing age, decreased performance status, and refractory disease. Follicular lymphoma (FL) and peripheral T cell lymphoma had improved survival compared to aggressive B cell lymphomas. Factors adversely associated with progression-free survival (PFS) included performance status, histology, and disease status at transplant. Long-term failure-free survival is possible following unrelated donor transplantation for NHL, although early mortality was high in this large cohort.

Allogeneic cell-mediated immunotherapy at the stage of minimal residual disease following high-dose chemotherapy supported by autologous stem cell transplantation

Cumulative clinical experience suggests that immunotherapy may be an effective tool for eradicating tumor cells resistant to maximum tolerated doses of chemotherapy and radiation. Immunotherapy is much more effective when applied at the stage of minimal residual disease, especially against slowly growing tumors because development of graft-versus-leukemia, lymphoma, myeloma, or in a broader sense graft-versus-tumor effects renders immunotherapy more time consuming. Hence, eradication of rapidly growing bulky tumors may be difficult or impossible to achieve. Considering the fact that optimal immunotherapy may be accomplished in patients treated at the stage of minimal (MRD) disease, in patients with hematological malignancies and chemosensitive solid tumors a stage of MRD may be best achieved following administration of myeloablative high-dose chemotherapy or chemoradiotherapy supported by autologous stem cell transplantation (autoSCT). Taken together, immunotherapy following autoSCT may provide an ideal combination for improving the cure rate of otherwise incurable cancers, especially if tumor cells may respond to cytokine-mediated immunotherapy or cell-mediated cytokine-activated immunotherapy. Following lymphocyte depletion in the course of autoSCT, adoptive transfer of alloreactive or tumor-reactive lymphocytes may be much more effective due to the preponderance of anticancer effector cells on the one hand, and elimination or depletion of the patient's regulatory cells that may downregulate anticancer effector mechanisms.

Chemotherapy and Hematopoietic Stem Cell Transplantation for Adult T-Cell Lymphoblastic Lymphoma: Current Status and Controversies

Adult T-cell lymphoblastic lymphoma is a relatively rare aggressive type of non-Hodgkin lymphoma with frequent involvement of extranodal sites. Because of the rarity of this malignancy, it is treated variably and often suboptimally, using approaches similar to those used for other types of aggressive non-Hodgkin lymphomas, with the consequence that outcome is often suboptimal. The collective experience in the management of adult T-cell lymphoblastic lymphoma suggests a good outcome for patients with no adverse prognostic factors who are treated with an acute lymphocytic leukemia-like treatment strategy. Patients with adverse prognostic features should be considered for more aggressive therapy-specifically, high-dose chemotherapy and hematopoietic stem cell transplantation. This article will attempt to review the current status of chemotherapy treatment programs and the relative merits of the different hematopoietic stem cell transplantation programs in this disease, particularly in relation to the pathologic and clinical features that correlate with disease prognosis.

Reduced-intensity hematopoietic stem-cell transplantation for malignant lymphoma: a retrospective survey of 112 adult patients in Japan

We conducted a nation-wide survey of 112 adult Japanese patients who underwent reduced-intensity stem cell transplantation (RIST) from 1999 to 2002. Underlying diseases included indolent (n=45), aggressive (n=58) and highly aggressive lymphomas (n=9). Median age of the patients was 49 years. A total of 40 patients (36%) had relapsed diseases after autologous stem cell transplantation and 36 patients (32%) had received radiotherapy. RIST regimens were fludarabine-based (n=95), low-dose total body irradiation-based (n=6) and others (n=11). Cumulative incidences of grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD were, respectively, 49 and 59%. Cumulative incidences of progression and progression-free mortality were 18 and 25%, respectively. With a median follow-up of 23.9 months, 3-year overall survival rates were 59%. A multivariate analysis identified three significant factors for progression, which are history of radiation (relative risk (RR) 3.45, confidential interval (CI) 1.12-10.0, P=0.03), central nervous system involvement (RR 6.25, CI 2.08-20.0, P=0.001) and development of GVHD (RR 0.28, CI 0.090-0.86, P=0.026). RIST may have decreased the rate of transplant-related mortality, and GVHD may have induced a graft-versus-lymphoma effect. However, whether or not these potential benefits can be directly translated into improved patient survival should be evaluated in further studies.

The role of allogeneic transplantation in non-Hodgkin's lymphoma

The evolution of combination chemotherapy regimens, combined with improvements in supportive care, has incrementally improved survival outcomes for patients with non-Hodgkin's lymphomas (NHL). Although 40-60% of younger patients with diffuse large cell lymphoma can now expect to be cured, significant numbers will either fail to achieve a remission or relapse after attaining a remission. In addition, certain histological subtypes are associated with particularly poor prognoses with combination chemotherapy alone (e.g. mantle cell lymphoma, B-cell prolymphocytic leukaemia). Relatively few of these patients can achieve long-term responses. Other NHL subtypes, whilst associated with more favourable prognoses in terms of overall survival, are rarely, if ever, cured (e.g. most low grade NHL including follicular lymphoma, chronic lymphocytic leukaemia and small lymphocytic lymphoma). For these reasons dose escalation and allogeneic transplantation have been investigated as potential ways of improving outcome, although this has mainly been in the setting of advanced disease. Any possible benefits have frequently been out-weighed by procedural morbidity and mortality. The parallel development of transplantation approaches that limit procedural toxicity along with advances in supportive care require that the role of allogeneic haematopoietic stem cell transplantation in the management of lymphoma be re-evaluated.

Graft-versus-lymphoma effects: clinical review, policy proposals, and immunobiology

The indubitable existence of a graft-versus-lymphoma (GVL) effect is difficult to prove directly. This article reviews the difficulties in interpreting the current literature in this field and, with a number of caveats, argues for the existence of a clinically meaningful GVL effect in follicular, mantle cell, small lymphocytic, and Hodgkin lymphomas. The evidence, however, for a potent GVL effect in diffuse large-cell lymphoma and Burkitt lymphoma is not convincing. Policies for allografting in lymphoma are proposed on the basis of this evidence. The immunobiology of GVL effects is discussed--in particular, the expression of HLA class I and II and co-stimulatory molecules on lymphomas that influence the generation of alloreactive T cells--together with future directions in immunotherapy that may help to eradicate chemoresistant disease.

Comparison of 100-day mortality rates associated with i.v. busulfan and cyclophosphamide vs other preparative regimens in allogeneic bone marrow transplantation for chronic myelogenous leukemia: Bayesian sensitivity analyses of confounded treatment and center effects

We evaluated the 100-day mortality rates associated with busulfan-based myeloablative conditioning regimens based on data from 1812 chronic myelogenous leukemia patients who underwent allogeneic blood or marrow transplantation (allotx). In all, 47 patients received intravenous (i.v.) busulfan and cyclophosphamide (i.v.BuCy2) with allotx at MD Anderson Cancer Center (MDACC) during 1995-1999. The remaining 1765 patients, whose data were supplied by the International Bone Marrow Transplant Registry (IBMTR), received alternative preparative regimens, primarily Cy-total body irradiation ( approximately 45%) or oral BuCy ( approximately 35%) during 1997-1998. As patients were not randomized between conditioning regimens, the i.v.BuCy2-versus-alternative treatment effect is confounded with a possible center effect due to nontreatment differences associated with factors differing between MDACC and the IBMTR centers. Additional complications are that the i.v.BuCy2-MDACC patients all survived 100 days, and three prognostic subgroups were included. Bayesian sensitivity analyses were performed to assess treatment effect on the probability of 100-day mortality, over a range of possible MDACC-versus-IBMTR center effects. For these patients, the posterior probability that i.v.BuCy2 was superior to alternative conditioning regimens ranges from 0.54 to 0.99, depending on prognosis and the magnitude of the assumed center effect.

Are HLA antigens a risk factor for acute GVHD in thalassemic patients receiving HLA-identical stem cell transplantation?

We retrospectively evaluated the association between risk factors and acute graft-versus-host disease (aGVHD) among 182 beta thalassemia patients who received 73 peripheral blood stem cell (PBSC) or 109 bone marrow transplants from HLA-identical siblings between 1991 and 2003. The relationship between the severity of aGVHD was examined for the following factors: HLA antigens, age, sex, ABO mismatch, sex mismatch (between recipient and donor), thalassemia class, graft source, transplant cell dose, CD3+ cell dose, conditioning regimen, GVHD prophylaxis, neutrophil engraftment duration, and blood product transfusions using univariate and multivariate analyses. Overall 61 (34%) patients developed clinical grade III or grade IV aGVHD. Univariate analysis confirmed an increased risk of severe aGVHD, which was associated with HLA-A11, HLA-A26, and PBSCT (P=.04, .03, and .03, respectively). The risk of aGVHD was reduced in the presence of HLA-A3 (P=.03). Multivariate analysis confirmed the increased risk of aGVHD associated with HLA-A11 (P=.04), HLA-A26 (P=.01), and a short-period neutrophil recovery (P=.009). In this study HLA-A11, HLA-A26, PBSCT, and a short neutrophil engraftment period were probable risk factors and HLA-A3 a probable protective factor associated with severe aGVHD. These data may provide useful guidelines to choose strategies for treatment and prevention.

Nonmyeloablative allogeneic hematopoietic transplantation: a promising salvage therapy for patients with non-Hodgkin's lymphoma whose disease has failed a prior autologous transplantation

PURPOSE

Allogeneic transplantation for patients with lymphoma who experience a recurrence after an autologous transplantation has been considered a hazardous therapeutic choice. We investigated the safety and efficacy of nonmyeloablative stem-cell transplantation in these patients.

PATIENTS AND METHODS

Patients were required to have chemosensitive or stable disease. Twenty consecutive patients were treated in two sequential trials. Fifteen patients underwent a preparative regimen of fludarabine (30 mg/m(2) daily for 3 days), intravenous cyclophosphamide (750 mg/m(2) daily for 3 days), and rituximab. For the remaining five patients, the conditioning regimen consisted of cisplatin (25 mg/m(2) continuous infusion daily for 4 days), fludarabine (30 mg/m(2) daily for 2 days), and cytarabine (1,000 mg/m(2) daily for 2 days). Tacrolimus and methotrexate were used for graft-versus-host disease prophylaxis.

RESULTS

All patients experienced engraftment of donor cells. One patient (5%) experienced grade 2 acute graft-versus-host disease, and no patients experienced a higher grade. One patient experienced disease progression at 115 days post-transplantation and responded to donor lymphocyte infusion. The remaining patients remained disease-free. One patient died at 10.5 months from a fungal infection. With a median follow-up time of 25 months, the estimated 3-year current progression-free survival rate was 95%.

CONCLUSION

These data suggest that nonmyeloablative allogeneic stem-cell transplantation is an effective option in lymphoma patients with chemosensitive or stable disease who experience disease recurrence following autologous transplantation.

High dose chemotherapy and autologous stem cell transplantation for poor risk and recurrent non-Hodgkin's lymphoma: a single-center experience of 50 patients

BACKGROUND

The long-term survival of patients with non-Hodgkin's lymphoma after conventional chemotherapy is about 35%, with the remaining 65% of patients tending to be refractory or experience relapse. As such, primary refractory patients responding to salvage chemotherapy, and sensitive relapsed patients and primary high-risk patients are recommended to receive high-dose chemotherapy (HDC) and autologous peripheral blood stem cell transplantation (PBSCT). We evaluated the role of HDC and autologous PBSCT in patients with primary refractory, primary high risk, and sensitive relapsed non-Hodgkin's lymphoma.

METHODS

We performed a retrospective analysis of the data from 50 patients with non-Hodgkin's lymphoma who were treated with HDC and autologous PBSCT in the Catholic Hematopoietic Stem Cell Transplantation Center between 1997 and 2002.

RESULTS

Of the 50 patients, the conditioning regimen was BEAM in 20, CMT (cyclophosphamide, melphalan and thiotepa) in 19, fludarabine- and total body irradiation (TBI)-based regimen in 8, and cyclophosphamide and TBI in 2. There were 3 (6%) deaths due to treatment-related toxicity within the first 50 days after transplantation. Twenty-five patients remain alive at a median follow-up duration of 40.5 months (range 9-61). Among the patients with partial response before transplantation, 76% showed further response after transplantation. In half of these responders, the disease state was changed into complete response (CR) after transplantation. 2-year overall survival was 52% and 2-year progression free survival was 36.8%. Median overall survival was 34 months (range 8-60), and median progression-free survival was 8 months (range 1-14). Median overall survival was 14 months (range 9-19) in the primary high-risk group (n=13), 7 months (range 4-10) in the resistance relapse group (n=5), and 6 months (range 0-14) in the primary refractory group (n=10). Overall survival in the sensitive relapse group (n=22) did not reach the median; the mean overall survival in this group was 33 months. The disease status before transplantation was the only significant prognostic factor in determining overall survival (p=0.032) and progression- free survival (p=0.001).

CONCLUSION

HDC and autologous PBSCT appears to produce high response rate. Primary high-risk group and sensitive relapse group had good prognosis, while refractory and resistance relapse group had poor prognosis. And the pre-transplantation disease status was the only significant prognostic factor in multivariate analysis.

Allogeneic Hematopoietic Stem Cell Transplantation for Lymphoma

For patients with relapsed or refractory Hodgkin's or non-Hodgkin's lymphomas, allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option when autologous HSCT fails to achieve durable remission or is deemed inappropriate. Allogeneic HSCT can result in long-term survival even in patients with refractory lymphomas. The efficacy of allogeneic HSCT is attributed, at least in part, to an immune-mediated graft-versus-lymphoma (GVL) effect that can also be associated with significant toxicity resulting from graft-versus-host disease. However, clinical evidence of a potent GVL effect is inconsistent. Reduced-intensity conditioning before allogeneic HSCT can facilitate the use of this treatment in older patients and those at high risk. The decrease in toxicity with reduced-intensity regimens may be associated with a loss of antitumor effects. Patients with lymphoma should be selected for allogeneic HSCT on the basis of characteristics that strongly influence transplant outcomes, including histology, chemosensitivity, and donor source.

Nonablative allogeneic stem-cell transplantation for advanced/recurrent mantle-cell lymphoma

PURPOSE

Patients with relapsed mantle-cell lymphoma have poor prognosis and short survival. Our aim was to determine the efficacy of nonablative allogeneic stem-cell transplantation in patients with relapsed mantle-cell lymphoma.

PATIENTS AND METHODS

Eighteen patients were treated in one of two consecutive trials. Thirteen patients underwent a conditioning regimen of fludarabine (30 mg/m2 daily for 3 days), cyclophosphamide (750 mg/m2 daily for 3 days), and high-dose rituximab. For the remaining five patients, the conditioning regimen consisted of cisplatin (25 mg/m2 daily for 4 days), fludarabine (30 mg/m2 daily for 2 days), and cytarabine (1,000 mg/m2 daily for 2 days). Tacrolimus and methotrexate were used for graft-versus-host disease prophylaxis.

RESULTS

The median age was 56.5 years. Patients underwent a median of three prior chemotherapy regimens. Prior autologous transplantation failed in five (28%) patients and 16 (89%) had chemosensitive disease. Donor cell engraftment occurred in all patients. Eight patients (44%) required no platelet or RBC transfusion, and acute graft-versus-host disease of greater than grade 2 did not develop in any patient. The day-100 mortality was 0%. Complete remission (CR) occurred in 17 patients. Three patients progressed, and one was reinduced into continuous CR with donor lymphocyte infusion. With a median follow-up period of 26 months, the actuarial probability of current-event-free-survival at 3 years was 82% (95% CI, 65% to 99%).

CONCLUSION

Our data suggest that nonablative allogeneic transplantation is a safe and potentially effective strategy for patients with relapsed and chemosensitive mantle-cell lymphoma.

Current trends in large cell lymphoma

For the last decade, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been the best available standard of care for aggressive non-Hodgkin's lymphoma (NHL), based on equivalent therapeutic results with other multiagent chemotherapy accompanied by lower costs and lesser toxicity. However, only 40-45% of these patients are cured with CHOP. New treatment strategies have been employed, including the addition of Rituximab to CHOP in elderly patients; dose escalation using granulocyte-colony-stimulating factor; overcoming the multidrug resistance phenotype with infusional chemotherapeutic regimens and use of some newer agents. Furthermore, the International Prognostic Factor index (IPI) has permitted identification of subsets of patients with large variations in prognosis, allowing prognosis specific therapy to be tested. There is now accumulating evidence that the clinical behavior of certain NHL can be profiled by the expression of certain molecular markers, which will undoubtedly play a role in the development of new prognostic models that may refine our ability to identify poor-risk patients. Regardless, there is still significant opportunity for improving survival in large cell lymphomas.

Nonmyeloablative transplantation for lymphoma

Nonmyeloablative stem cell transplantation, also referred to as minitransplantation or reduced-intensity transplantation, is a novel approach to lymphoma treatment offering the lure of harnessing graft-versus-lymphoma (GVL) effects while decreasing regimen-related toxicity. The general concept is to provide a sufficiently immunosuppressive and moderately myelosuppressive treatment regimen to allow donor and host hematopoietic coexistence or chimerism. The most popular regimens incorporate a purine analog (eg, fludarabine) and an alkylating agent (eg, cyclophosphamide or melphalan). Newer regimens include the monoclonal antibody alemtuzumab, which may reduce the incidence of acute graft-versus-host disease (GVHD). Early reports demonstrate a GVL effect; however, the underlying lymphoma subtype and pace of disease often dictate which patients can capitalize on GVL benefits. Clinical reports show mixed results, which may reflect variations in patient selection. Although most patients successfully engraft, the effect on lymphoma control and GVHD must be evaluated carefully. Future investigations continue to delineate the optimal timing of nonmyeloablative transplantation, the optimal patient population, the optimal preparative regimen, and the optimal GVHD prophylaxis. Supportive care remains a critical component of management because the reduced-intensity regimens do not abrogate the risk of serious infection and many do not appear to decrease the incidence of chronic GVHD. Nonmyeloablative hematopoietic stem cell transplantation may broaden the applicability of allogeneic transplantation in malignant lymphomas, especially for indolent subtypes.

High complete response rate after allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning regimens in advanced malignant lymphoma

The possible advantage of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a graft-versus-lymphoma effect. We explored the feasibility and efficacy of allo-HSCT with reduced-intensity (RI) regimens in advanced malignant lymphoma (ML). A total of 20 patients with indolent (n=9) or aggressive lymphoma (n=11) received allo-HSCT with an RI regimen (RIST). The preparative regimen consisted of a combination of purine analog and alkylating agent with or without antithymocyte globulin. A total of 11 patients had chemorefractory disease, seven had chemosensitive relapsed disease and two had residual disease. All of the patients received G-CSF-mobilized blood stem cells from HLA-matched siblings. Of the 20 patients, 19 achieved engraftment with acceptable regimen-related toxicities. Seven patients developed grade II-IV acute GVHD and 15 developed chronic GVHD. Of the 15 patients with evaluable disease, 12 achieved a complete response. One died of invasive fusariosis, four subsequently died of GVHD complicated with fungal infection and one died of progressive disease. With a median follow-up of 358 days, the Kaplan-Meier estimates for 1-year overall and progression-free survival were both 70%. The high response rate with low relapse observed in this study suggests that RIST may be an effective alternative curative treatment for patients with advanced ML.

Why aren't we performing more allografts for aggressive non-Hodgkin's lymphoma?

Allogeneic stem cell transplantation has an under-appreciated role in the management of intermediate-grade non-Hodgkin's lymphoma. It provides several advantages over autologous stem cell transplantation including provision of a lymphoma-free graft, reduced rates of secondary myelodysplastic syndrome and leukemia, and a potentially curative graft-versus-lymphoma effect. When applied to chemosensitive patients, the lower relapse rates and reasonable long-term outcomes make allogeneic transplantation a promising therapy to pursue. Patient populations, such as those with bone marrow involvement or very high-risk disease, can be identified as having suboptimal outcomes after autotransplantation and may benefit from such an approach. While the exact role of allogeneic stem cell transplantation remains to be determined, broad recommendations can be suggested for the management of patients with intermediate-grade lymphoma. New approaches to allogeneic transplantation, including the use of matched-unrelated donors and reduced-intensity conditioning regimens, may expand the applicability of this potentially curative modality.

A comparison of allogeneic and autologous bone marrow transplantation for lymphoblastic lymphoma

Lymphoblastic lymphoma (LBL) is a rare, clinically aggressive neoplasm of the young that frequently involves the bone marrow (BM) and/or central nervous system. Because LBL is similar to acute lymphoblastic leukemia, some centers prefer allogeneic hematopoietic stem cell (SC) transplantation to autologous SC transplantation. We retrospectively analyzed outcomes for patients who underwent autologous (auto, n = 128) or HLA-identical sibling (allo, n = 76) SC transplantations from 1989 to 1998 and were reported to International Bone Marrow Transplant Registry (IBMTR) or Autologous Blood and Marrow Transplant Registry (ABMTR). Allo stem cell transplant (SCT) recipients had higher treatment-related mortality (TRM) at 6 months (18% versus 3%, P =.002), and this disadvantage persisted at 1 and 5 years. Early relapse rates after alloSC transplantation and autoSC transplantation were similar, but significantly lower relapse rates were observed in alloSCT recipients at 1 and 5 years (32% versus 46%, P =.05; and 34% versus 56%, P =.004, respectively). No differences were noted in lymphoma-free survival rates between alloSC transplantations and autoSC transplantations (5-year rates 36% versus 39%, P =.82). AutoSCT recipients had higher overall survival at 6 months (75% versus 59%, P =.01), but survival did not significantly differ between the 2 groups at 1 and 5 years (60% versus 49%, P =.09; 44% versus 39%, P =.47, respectively). Multivariate analyses to account for confounding factors confirmed these results. Independent of SCT type, BM involvement at the time of transplantation and disease status more advanced than first complete remission were associated with inferior outcomes. In summary, alloSC transplantation for LBL is associated with fewer relapses than with autoSC transplantation, but higher TRM offsets any potential survival benefit.

Autologous and allogeneic stem cell transplantation in Waldenstrom's macroglobulinemia: review of the literature and future directions

Waldenstrom's macroglobulinemia (WM) is a chronic lymphoproliferative disorder characterized by lymphoplasmacytic infiltrate and a monoclonal IgM serum peak. Treatment includes cytotoxic chemotherapy with alkylators, or purine nucleoside analogues and monoclonal anti-CD20 antibody. The role of stem cell transplantation (SCT) in WM has not been established. We identified 24 published cases of WM treated with high-dose chemotherapy (HDC) followed by autologous SCT (ASCT). The median age was 50 years; half of the patients had refractory disease and received a variety of preparative regimens. Nine complete and 14 partial responses were observed, with one early death. Fifteen patients were alive and well at follow-ups ranging from 1 to 132 months. Six additional patients, with a median age of 45 years (range, 30 to 62), who received allogeneic SCT have been reported. All were heavily pretreated with refractory or relapsed disease. Median time from diagnosis to transplant was 3.1 years (range, 1.3 to 7). Two patients died of complications of the procedure while one died of disease progression. Three patients were alive and well between 5 and 112 months post-transplant. The small number of reported patients precludes any significant conclusion except that SCT is feasible in WM and long-term disease control can be achieved in selected patients with autologous or allogeneic SCT, even in those with refractory disease.

An EBMT registry matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation

The role of allogeneic bone marrow transplantation in lymphoma remains uncertain. We have analyzed 1185 allogeneic transplants for lymphoma reported to the EBMT registry between 1982 and 1998 and compared the results with those of 14687 autologous procedures performed over the same period. Patients receiving allogeneic transplants were subdivided according to histology: low-grade non-Hodgkin's lymphoma (NHL) 231 patients; intermediate-grade NHL 147 patients; high-grade NHL 255 patients; lymphoblastic NHL 314 patients; Burkitt's lymphoma 71 patients; and Hodgkin's disease 167 patients. These patients received allogeneic transplants as their first transplant procedure. Actuarial overall survival (OS) at 4 years from transplantation was: low-grade NHL 51.1%; intermediate-grade NHL 38.3%; high-grade NHL 41.2%; lymphoblastic lymphoma 42.0% years; Burkitt's lymphoma 37.1%; and Hodgkin's disease 24.7% years. These outcomes are relatively poor because of the high procedure-related mortality associated with these procedures, particularly in patients with Hodgkin's disease (51.7% actuarial procedure-related mortality at 4 years). Multivariate analysis showed that for all lymphomas apart from Hodgkin's disease, status at transplantation significantly affected outcome. A matched analysis was performed: for all categories of lymphoma, OS was better for autologous than for allogeneic transplantation. Relapse rate was better in the allogeneic group for low-, intermediate- and high-grade, and lymphoblastic NHL. It was equivalent for Burkitt's lymphoma and worse in the allogeneic group for Hodgkin's disease. Allogeneic transplantation appears to be superior to autologous procedures in terms of producing a lower relapse rate. The toxicity of allogeneic procedures must however be reduced before this translates into an improvement in OS.

Autologous hematopoietic transplantation for low-grade lymphomas

BACKGROUND

Autologous stem cell transplantation (SCT) has become the treatment of choice for patients with relapsed chemo-sensitive intermediate grade lymphoma, but its role in the treatment of low-grade lymphomas and in selected patients in first remission remains controversial.

METHODS

A large number of clinical trials have evaluated the role autologous SCT in both low grade and intermediate grade non-Hodgkin's lymphomas (NHL). These studies have attempted to evaluate the role of high dose therapy with stem cell support in comparison to more conventional chemotherapy approaches. Studies have also focused on methods to assess whether contaminating tumor cells are contained with the stem cell collection and whether this has impact on outcome. With an increased number of patients now long term survivors, additional studies are focusing on long term complications and in particular the emergence of secondary malignancies.

RESULTS

Virtually all patients now receive peripheral blood stem cells rather than bone marrow as a source of stem cells. The role of purging of residual tumor cells remains controversial and no randomized trial has been published to date that could evaluate the clinical utility of cell manipulation to attempt to remove contaminating lymphoma cells. Secondary leukemia is emerging as a major source of long-term morbidity and mortality after autologous stem cell transplantation.

CONCLUSION

Autologous SCT is associated with improved outcome in patients with relapsed intermediate grade lymphoma and most likely prolongs disease free survival in patients with low grade NHL. Morbidity and mortality of the procedure is low and major efforts are being made to attempt to decrease the major causes of failure, which remain disease relapse and occurrence of secondary malignancies.

Autologous and allogeneic transplantation for aggressive NHL

BACKGROUND

Intermediate- and high-grade NHL are generally chemosensitive diseases with high initial response rates to combination chemotherapy. Dose intensification via autologous and allogeneic transplantation provides viable treatment options in specific clinical settings. Currently, autologous transplantation is the standard of care for relapsed but chemosensitive aggressive B-cell NHL. However, tools such as the International Prognostic Index allow risk-adapted analyses, and show that the magnitude of benefit from autologous transplantation differs in lymphoma subsets.

METHODS

Low-risk patients appear to do well regardless of salvage approaches, whereas high-risk patients have suboptimal outcomes with autologous transplantation. In high-risk patients, high-dose chemotherapy with autologous stem-cell transplantation has been examined as part of initial therapy, with long-term data promising but still evolving.

DISCUSSION

A significant concern with autologous transplantation in aggressive and high-grade NHL is the risk of graft contamination with tumor cells. Several investigators have demonstrated the presence of malignant cells in both BM and PBSC, although the clonagenic potential of such cells is unclear. Allogeneic stem-cell transplantation has several potential advantages over autologous transplantation for NHL,including procurement of an uncontaminated stem-cell graft, GvL effects, and the elimination of hematopoietic stem-cell damage and consequent secondary leukemia.

RESULTS

The ideal application of allogeneic transplantation in aggressive and high-grade lymphomas is still unclear; but the lower relapse rates demonstrated in several comparisons of the two approaches make this an exciting area to pursue. Finally, non-myeloablative stem-cell transplantation may broaden the use of allogeneic transplantation by lowering regimen-related mortality while capitalizing on GvL.

The choice of allogeneic or autologous hematopoietic transplantation for NHL

NHL constitutes the sixth most common malignancy diagnosed in the USA every year, accounting for approximately 24,400 deaths. Although a subset of patients can be cured with chemotherapy or radiation therapy, the outlook is generally poor for patients with refractory or recurrent disease. High-dose therapy supported by both autologous and allogeneic transplantation has been widely studied in this group of patients. Autologous transplantation may be considered standard therapy for patients with diffuse large-cell NHL in chemotherapy-sensitive relapse. Selected categories of patients with other histologic subtypes may also benefit from this strategy. Allogeneic transplantation using high-dose myeloablative conditioning regimen is an effective, yet hazardous approach. A GvL effect leads to a lower rate of disease recurrence than occurs with autologous transplants, but this benefit is offset by higher risk of treatment related mortality. The recent use of less toxic non-myeloablative conditioning regimens for allogeneic transplantation has reduced the risk of transplant-related mortality, allowing this approach even in older or medically infirm patients. Nonablative allogeneic transplants are a promising strategy, particularly for patients with indolent lymphoid malignancies.

Treatment of lymphoblastic lymphoma in adults

Lymphoblastic lymphoma (LBL) is a rare subtype of non-Hodgkin's lymphoma (NHL) with biological features similar to those of acute lymphoblastic leukaemia. In the majority of cases LBL shows a T-cell phenotype, and mediastinal tumours are the most frequent manifestation. Outcomes of LBL patients treated according to NHL or ALL-type regimens are reviewed. Since prophylaxis of CNS relapse and local recurrence emerged as important issues in the treatment of LBL the different options are discussed. Several studies have used autologous stem cell transplantation (SCT) in the primary treatment of LBL and results are reviewed. The analysis of published prognostic factors and models in LBL demonstrates that, at present, no convincing risk model is available for LBL treated according to contemporary intensive chemotherapy protocols. Therefore indications for SCT in first complete remission (CR) cannot be defined. Future prospects for improvement of treatment results in LBL include intensification of chemotherapy, definition of prognostic factors, evaluation of minimal residual disease and SCT in high-risk patients.

Critical review on non-myeloablative stem cell transplantation (NST)

Allogeneic stem cell transplantation is an established treatment modality for a variety of hematologic malignancies. Unfortunately, it carries a high risk of complications and toxicities related to the intensive preparative regimen which is traditionally used for pre-transplant myeloablation and the graft versus host disease, which may be life threatening. Thus allogeneic stem cell transplantation has been used only for younger patients with a good performance status, excluding many other potential candidates due to advanced age or comorbid conditions. Using reduced intensity preparative regimens for allogeneic stem cell transplantation (non-myeloablative stem cell transplantation (NST)) researchers attempted to overcome these barriers in patients' selection and tried to make hematopoietic stem cell (HSC) transplantation a safer procedure. The well-described graft versus malignancy effect would be the most curative element in this treatment. After more than 5 years of cumulative clinical experience, we know that NST is a feasible treatment option for patients with suboptimal performance status and is mostly effective in slow proliferating malignancies, which gives time for a graft versus malignancy effect to take place. Additionally achievement of stable donor cell engraftment with NSTs provides a platform for adoptive immune cell treatments and is promising for extended indications of stem cell transplantation in the future.

Allogeneic haemopoietic stem cell transplantation for non-Hodgkin's lymphoma

This chapter outlines the rationale for allogeneic haemopoietic stem cell transplantation in non-Hodgkin's lymphoma and pertinent results from published studies. Trials comparing allogeneic with autologous transplantation are discussed, as are disease-specific results for low-grade (including transformed), mantle cell and high-grade (Burkitt's and lymphoblastic) subtypes of the disease. Allogeneic transplantation for non-Hodgkin's lymphoma in the paediatric population, the use of unrelated donors, allografting after failed autologous or allogeneic transplantation, the graft-versus-lymphoma effect, the use of donor leukocyte infusions and non-myeloablative allografts are considered.

Update on non-myeloablative stem cell transplantation for hematologic malignancies

Allogeneic stem cell transplantation is an established treatment modality for a variety of hematologic malignancies. Unfortunately it carries a high risk of complications and toxicities related to the intensive preparative regimen which is traditionally used for pre-transplant myeloablation and the graft versus host disease, which may be life threatening. Thus allogeneic stem cell transplantation has been used only for younger patients with a good performance status, excluding many other potential candidates due to advanced age or comorbid conditions. Non ablative or reduced intensity preparative regimens for allogeneic stem cell transplantation (NST) have been proposed as a strategy that would allow exploiting the graft versus tumor effect of allogeneic transplantation without the toxicity of myeloablative therapy. After more than five years of cumulative clinical experience, it is now well established that NST is a feasible treatment option for patients with suboptimal performance status and is mostly effective in slow proliferating malignancies, which gives time for a graft versus malignancy effect to take place. Additionally achievement of stable donor cell engraftment with NSTs provides a platform for adoptive immune cell treatments and may allow to extend indications of stem cell transplantation in the future.

Allogeneic hematopoietic stem cell transplantation for progressive follicular lymphoma

Between 1993 and 2000, 24 patients with follicular lymphoma underwent high-dose chemo/radiotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). Median age was 44 years, median interval from diagnosis to HSCT was 24 months and the median number of prior lines of treatment was three. Donor source was HLA matched sibling (23) or matched unrelated donor (one). Conditioning therapy was busulfan based in 22 patients and included total body irradiation in two. All patients received i.v. cyclosporine A and short-course methotrexate for GVHD prophylaxis. Nineteen patients are alive, a median of 2.3 years post HSCT. Death occurred due to transplant complications in four patients and one patient died of a stroke 10 months post HSCT. No patients have relapsed. The overall and progression-free survival was 78% (95% CI 63-97). Allogeneic HSCT for patients with progressive follicular lymphoma is feasible and may result in prolonged disease-free survival.

Stem cell transplantation (SCT) for Waldenstrom's macroglobulinemia (WM)

Waldenstrom's macroglobulinemia (WM) is a low-grade lymphoplasmacytoid malignancy of unknown etiology. It primarily affects elderly patients and is characterized by a monoclonal IgM component, varying degrees of cytopenias, lymphadenopathy and manifestations related to hyperviscosity syndromes. WM is usually treated with single agent nucleoside analogues or alkylating agents that often provide high response rates and durable remissions. Recurrence of the disease after primary therapy is not uncommon, and resistance to both alkylating agents and nucleoside analogs eventually emerges. Small numbers of patients have undergone high-dose chemotherapy (HDC) with either autologous (n = 24) or allogeneic (n = 6) stem cell transplantation (SCT) as treatment for this disease. Most patients in both groups achieved remission. Results are promising and a more in-depth analysis of possible applications of this treatment modality is attempted with this mini-review.

Graft versus Burkitt's lymphoma effect after allogeneic marrow transplantation

While modern intensive chemotherapy protocols cure the majority of patients with Burkitt's lymphoma, the prospects of cure with salvage chemotherapy for relapsed or refractory disease are minimal. There are limited data on the results of allografting for well characterised Burkitt's lymphoma and in particular little on the impact of GVHD on transplant outcome. We report a patient with t(8;22) Burkitt's lymphoma who underwent an HLA-identical sibling allograft in second complete remission. Relapse occurred at day 60 post-transplant, without pre-existing GVHD. GVHD subsequently developed after withdrawal of immunosuppression and administration of alpha-interferon. Concomitantly the lymphoma regressed, consistent with a graft versus Burkitt's effect, until progression at day 200. A delayed, partial and transient response subsequently occurred to rituximab, a chimeric monoclonal antibody against the CD20 antigen. These observations suggest that immunotherapeutic approaches should be considered for Burkitt's lymphoma unable to be cured by conventional chemotherapy.

High-dose therapy for indolent lymphoma

Stem-cell transplantation (SCT) has become the treatment of choice for patients with relapsed aggressive non-Hodgkin's lymphoma (NHL). However, the role of SCT in the management of patients with indolent NHL remains controversial. Indolent follicular lymphomas are diseases which are generally incurable with conventional therapy. Although patients can survive for prolonged periods, the median duration of first remission is approximately 3 years, and subsequent remissions are progressively shorter with time. Emerging evidence suggests that high-dose chemotherapy with SCT leads to prolonged disease-free and overall survival in a subset of patients with indolent NHL. However, there is increasing concern regarding the toxicity of SCT, especially the long-term risk of developing myelodysplastic syndrome. It is still unclear as to when this approach should be used. Poorer outcomes have been obtained in heavily pretreated patients but encouraging results are being reported for patients undergoing SCT early during the course of their disease. Investigators are now focusing on how to improve SCT efficacy in order to eradicate minimal residual disease. Many ongoing studies are especially exploring the impact of stem-cell purging and novel ablative regimens combined with allogeneic transplantation.

Nonablative allogeneic hematopoietic transplantation as adoptive immunotherapy for indolent lymphoma: low incidence of toxicity, acute graft-versus-host disease, and treatment-related mortality

This study investigated the use of a nonablative conditioning regimen to decrease toxicity and achieve engraftment of an allogeneic blood stem cell transplant, allowing a graft-versus-malignancy effect to occur. All patients had follicular or small cell lymphocytic lymphoma after relapse from a prior response to conventional chemotherapy. Patients received a preparative regimen of fludarabine (25 mg/m(2) given daily for 5 days or 30 mg/m(2) daily for 3 days) and intravenous cyclophosphamide (1 g/m(2) given daily for 2 days or 750 mg/m(2) daily for 3 days). Nine patients received rituximab in addition to the chemotherapy. Tacrolimus and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. Twenty patients were studied; their median age was 51 years. Twelve were in complete remission (CR) at transplantation. All patients achieved engraftment of donor cells. The median number of days with severe neutropenia was 6. Only 2 patients required more than one platelet transfusion. The cumulative incidence of acute grade II to IV GVHD was 20%. Only one patient developed acute GVHD of greater than grade II. All patients achieved CR. None have had a relapse of disease, with a median follow-up period of 21 months. The actuarial probability of being alive and in remission at 2 years was 84% (95% confidence interval, 57%-94%). Nonablative chemotherapy with fludarabine/cyclophosphamide followed by allogeneic stem cell transplantation is a promising therapy for indolent lymphoma with minimal toxicity and myelosuppression. Further studies are warranted to compare nonablative allogeneic hematopoietic transplantation with alternative treatment strategies.

Impact of high-dose chemotherapy on peripheral T-cell lymphomas

PURPOSE

To evaluate the outcome of high-dose chemotherapy (HDCT) and autologous or allogeneic hematopoietic transplantation in patients with peripheral T-cell lymphoma (PTCL) who experienced disease recurrence after prior conventional chemotherapy.

PATIENTS AND METHODS

We performed a retrospective analysis of 36 PTCL patients from the University of Texas M.D. Anderson Cancer Center treated between 1989 and 1998 with HDCT and autologous or allogeneic hematopoietic transplantation.

RESULTS

A total of 36 patients were studied (29 received autologous transplantation, and seven received allogeneic transplantation). The overall survival rate at 3 years was 36% (95% confidence interval [CI], 23% to 59%), and the progression-free survival (PFS) rate was 28% (95% CI, 16% to 49%). The pretransplant serum lactate dehydrogenase level was the most important prognostic factor for both survival and PFS rates (P < .001). A Pretransplant International Prognostic Index score of < or = 1 indicated a superior survival rate (P = .036) but not an improved PFS rate. A median follow-up of 43 months (range, 13 to 126 months) showed 13 patients (36%) were still alive with no evidence of disease.

CONCLUSION

Our results are comparable to the published data on HDCT in B-cell non-Hodgkin's lymphoma (NHL) patients despite the fact that patients with PTCL are known to have a worse outcome compared with B-cell NHL patients. Considering the dismal outcome of conventional chemotherapy in PTCL patients, these data suggest the hypothesis that the poor prognostic implication of T-cell phenotyping in NHL might be overcome by frontline HDCT and transplantation.

New approaches to blood and marrow transplantation for patients with low-grade lymphomas

Low-grade lymphomas are generally considered incurable diseases with current standard therapies. Blood or marrow transplantation may be the exception. Nevertheless, the role of bone marrow transplantation in low-grade lymphomas has been limited by the usual indolent course of this heterogeneous group of diseases and the historically high rates of transplant-related mortality associated with most transplant procedures. This review discusses the current issues pertaining to bone marrow transplantation and comments on investigational approaches such as the use of monoclonal antibodies as in vivo purging mechanisms and nonmyeloablative and radioimmunoconjugated antibodies as alternate preparative regimens.

Reduced intensity conditioning: enhanced graft-versus-tumor effect following dose-reduced conditioning and allogeneic transplantation for refractory lymphoid malignancies after high-dose therapy

Non-myeloablative regimens have been proven to allow engraftment following allogeneic stem cells transplantation (allo-SCT) with minimal procedure-related toxicity. Conventional allo-SCT may produce remissions in patients with relapsed and refractory lymphoid malignancies (LM) but these good results may be achieved at the cost of high treatment-related morbidity and mortality. Application of allo-SCT using less intensive regimens may temper the frequency of these complications, allowing a potent graft-versus-tumor effect (GVT). We present our data on 11 patients with LM receiving allo-SCT with a reduced regimen. Ten patients had received previous high-dose therapy, and were at high risk for toxicity, thus precluding the use of allo-SCT. A fludarabine and low-dose busulfan combination facilitated engraftment while exerting GVT. Hematological recovery was quick, and full donor T cell chimerism preceded acute GVHD. GVHD and infections were the major problems. Spontaneous acute GVHD occurred in eight patients (72%). Five patients (45%) achieved complete remission, and the GVT effect was closely associated with GVHD. These results support the concept that GVT is effective against LM in patients who have been heavily pretreated. Further studies are needed to investigate strategies to generate more specific alloreactive effects providing optimal GVT and an acceptable risk of GVHD and infections.