Outcomes of hematopoietic cell transplantation for diffuse large B cell lymphoma transformed from follicular lymphoma

Brentuximab vedotin therapy followed by autologous peripheral stem cell transplantation as a viable treatment option for an older adult with transformed lymphoma: a case report and literature review

This report presents a case involving a woman aged >65 years who had been diagnosed with marginal zone lymphoma 3 years prior. The patient was hospitalized with enlarged inguinal lymph nodes, and pathological examination revealed that the lymphoma had transformed into diffuse large B-cell lymphoma. After two cycles of brentuximab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (BV-R-CHP) chemotherapy, the patient achieved complete remission. This treatment was followed by autologous hematopoietic stem cell transplantation and lenalidomide maintenance therapy. At the last follow-up, the patient had been in continuous remission for 24 months. This case study suggests that the utilization of BV and R-CHP in conjunction can result in rapid remission, and it can be followed by autologous hematopoietic stem cell transplantation and maintenance therapy with lenalidomide. This treatment approach exhibits potential as a viable option for older individuals with transformed lymphoma.

Allogeneic Hematopoietic Stem Cell Transplantation in Transformed Follicular Lymphoma (tFL): Results of a Retrospective Multicenter Study from GELTAMO/GETH-TC Spanish Groups

BACKGROUND

Transformation of follicular lymphoma into an aggressive lymphoma (tFL) worsens the prognosis and the standard treatment is not completely defined. Allogeneic hematopoietic stem cell transplantation (alloSCT) could be a potentially curative option for these patients, but it has not been widely explored.

METHODS

We designed a retrospective multicenter study to analyze the efficacy and toxicity of alloSCT in tFL patients and potential prognostic factors of survival.

RESULTS

A total of 43 patients diagnosed with tFL who underwent alloSCT in 14 Spanish centers between January 2000 and January 2019 were included. Median age was 44 (31-67) years. After a median follow-up of 58 months, estimated 5-year overall survival (OS) and progression-free survival (PFS) were both 35%. Estimated 100-day and 1-year non-relapse mortality (NRM) were 20% and 34%, respectively. The type of conditioning regimen (3-year OS of 52% vs. 20%, respectively, for reduced-intensity vs. myeloablative conditioning) and development of chronic graft versus host disease (cGVHD) (3-year OS of 75% vs. 40%) were the only factors significantly associated with OS. The only variable with an independent association with OS was cGVHD (HR, 3.4; 95% CI, 1.2-9.6).

CONCLUSIONS

Our results indicate that alloSCT continues to be a potentially curative option for patients with tFL.

Outcomes of hematopoietic cell transplantation for transformed follicular lymphoma

This study characterized the outcomes of patients who underwent hematopoietic cell transplantation (HCT) for transformed follicular lymphoma (tFL), and clarified the association of low-dose anti-thymocyte globulin use with outcomes after allogeneic HCT. The retrospective study cohort included 74 consecutive patients who underwent autologous (n = 23) or allogeneic (n = 51) HCT at our center from 2000 to 2017. Compared with the allogeneic HCT group, the autologous HCT group underwent fewer systemic regimens before HCT (median 2 vs. 5, p < 0.001) and were more likely to have chemosensitive disease at HCT (100% vs. 82%, p = 0.05), while age, sex and HCT-specific comorbidity index were similar between the two groups. With a median follow-up of 5.8 years among survivors, the 5-year probability of progression-free survival was 64% after autologous HCT and 55% after allogeneic HCT (p = 0.21). The 5-year cumulative incidence of non-relapse mortality was 0% after autologous HCT and 9.5% after allogeneic HCT (p = 0.062). The 5-year cumulative incidence of disease progression was similar between autologous and allogeneic HCT (36% vs. 36%, respectively, p = 0.88). In the allogeneic HCT group, the use of low-dose anti-thymocyte globulin was associated with a lower incidence of severe acute GVHD but not with an increased risk of mortality or disease progression. More than half of patients with early phase chemosensitive tFL and approximately half of those with advanced-phase tFL achieved long-term progression-free survival with autologous and allogeneic HCT, respectively. Disease progression was the major cause of treatment failure after both types of HCT. Further strategies are needed to reduce the risk of disease progression.

Transformed lymphoma: what should I do now?

Although the majority of indolent lymphomas (focusing on follicular lymphoma [FL]) have a prolonged waxing and waning course, a portion of patients experience histologic transformation (HT) to either diffuse large B-cell lymphoma or a higher-grade morphology, often with acquisition of MYC and BCL2 and/or BCL6 rearrangements (high-grade B-cell lymphoma-double-hit lymphoma/triple-hit lymphoma). The overall incidence of HT and transformed follicular lymphoma (tFL) may be declining, but outcomes remain inferior to those in simple indolent lymphoma progression. Recent data suggest that the majority of HT cases occur in higher-risk patients with FL, and they occur early after initial chemoimmunotherapy, comprising the majority of patients with progression of disease within 24 months. This latter point emphasizes the need for a sufficient biopsy at relapse in FL. Treatment options depend on the prior therapy for the indolent component as well as the histology at relapse, but they generally follow several principles discussed in this article. Anthracycline-naïve patients have the best outcomes if there is HT, and responses to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) are similar to those of patients with de novo diffuse large B-cell lymphoma. Patients with anthracycline exposure prior to transformation have the best outcomes with salvage chemotherapy and a consolidative autologous stem cell transplant. However, a major challenge is the management of patients with tFL who experience relapse early after bendamustine-based treatment, in whom the role of consolidative transplant after anthracycline-based treatment is unclear. In the past several years, cellular therapy has emerged as an important tool for some but not all patients with tFL. This review focuses on the nuances of managing tFL.

NCCN Guidelines Insights: B-Cell Lymphomas, Version 3.2019

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin's lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

Cellular Therapy in Follicular Lymphoma: Autologous Stem Cell Transplantation, Allogeneic Stem Cell Transplantation, and Chimeric Antigen Receptor T-cell Therapy

A subset of follicular lymphoma patients with high-risk clinical features continues to pose a therapeutic challenge. Hematopoietic stem cell transplantation is a suitable consolidative treatment option for these patients. Data on chimeric antigen receptor T-cell therapy are promising in relapsed/refractory and transformed patients. The increasing armamentarium of nontransplant options coupled with the associated potential long-term sequelae of transplantation raises questions about the placement of transplant strategies in the follicular lymphoma treatment hierarchy.

Follicular lymphoma: Update on management and emerging therapies at the dawn of the new decade

Follicular lymphoma is the most common indolent non-Hodgkin lymphoma. Survival has improved over the last several decades, mainly because of the incorporation of the anti-CD20 antibody rituximab into preexisting or rediscovered agents. The disease has a relapsing and remitting pattern, coupled with a risk of transformation into an aggressive lymphoma, and considered incurable for most patients. Next-generation sequencing technologies have increased our understanding of the biology and genetic landscape of the disease, identifying potential druggable targets for treatment. Current prognostic models cannot accurately identify patients at risk of early progression and despite the availability of treatment options for relapsed/refractory disease, rational treatment selection balancing disease control, efficacy with toxicity, and quality of life remain unmet needs. This review provides an overview of biology, prognostication, treatment options, and emerging therapies that provide valid grounds for optimism.

Advances in Transplantation for Lymphomas Resulting from CIBMTR Lymphoma Working Committee's Research Portfolio: A Five-Year Report (2013-2018)

The Center for International Blood and Marrow Transplant Research (CIBMTR) is a research collaboration between the National Marrow Donor Program (NMDP)/Be The Match and the Medical College of Wisconsin (MCW). The CIBMTR collaborates with the global scientific community to advance hematopoietic cell transplantation (HCT) and cellular therapy worldwide to increase survival and enrich quality of life for patients. The observation research program within CIBMTR is organized into 15 working committees. This review is aiming to highlight the observational research studies published by the CIBMTR Lymphoma Working committee over the last five years (2013-18) and to summarize how these studies have impacted the field by helping inform clinical practice in scenarios where prospective data from high quality randomized trials were not available or where owing to the rarity of a particular transplant indication such data were unlikely to be generated, outside the setting of a large observational research database. The salient findings reviewed include; (a) studies supporting role of autologous HCT in diffuse large B-cell lymphoma (DLBCL) patients with sensitive relapse of disease within one year of diagnosis, (b) role of autologous HCT vs allogeneic HCT in follicular lymphoma patients with early therapy failure, (c) prognostic scoring system development for classical Hodgkin lymphoma and DLBCL patients with prior autograft failure, (d) defining the role of alternative donor transplantation in lymphomas, (e) evaluating appropriate conditioning regimens for HCT in lymphoma, and (f) outcomes of HCT in rare lymphoid malignancies.

An update in treating transformed lymphoma

Indolent lymphomas typically have a prolonged course and favorable prognosis. Recent data support survival times that can reach several decades, even if periodic treatment is needed to manage symptoms or stabilize disease. However, all indolent lymphomas have the potential to undergo transformation to an aggressive phenotype, clinically characterized by a rapid progression of adenopathy, new-onset constitutional symptoms, or laboratory abnormalities, and the immediate need for therapeutic intervention. The most common scenario is transformation of follicular lymphoma to either diffuse large B-cell lymphoma or high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 translocations; however, other indolent subtypes such as marginal zone lymphoma, lymphoplasmacytic lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, or even nodular lymphocyte predominant Hodgkin lymphoma, can undergo similar histologic transformation. The prognosis of transformed lymphomas has historically been quite poor, but there is ample evidence this is changing in the rituximab era. This article will provide a review of transformed lymphomas with an emphasis on treatment and the nuances of diagnosis and clinical management. Unless otherwise specified, all discussion in this review pertains to transformed follicular lymphoma which is the more common scenario and the subtype with the most robust data. In many cases, this information can be extrapolated and applied to other indolent histologies (i.e. transformed marginal zone lymphoma); however, several other clinical scenarios, such as Richter's transformation and "double hit" transformations, warrant a distinct discussion and will be reviewed separately.

Allogeneic haematopoietic cell transplantation offers the chance of cure for patients with transformed follicular lymphoma

PURPOSE

In patients with follicular lymphoma, secondary transformation to aggressive lymphoma (tFL) implies a poor prognosis. In principle, allogeneic haematopoietic cell transplantation (allo-HCT) offers a chance of cure for tFL but is rarely practiced. Aim of this retrospective multicenter study was to define the actual significance of allo-HCT in treatment of tFL.

METHODS

The database of the German Registry for Stem Cell Transplantation (DRST) was screened for patients who underwent allo-HCT for tFL 1998-2008. Confirmation of tFL-diagnosis by local and/or pathologists of the National NHL Board was mandatory for enrolment. Gaps in reported EBMT Minimum Essential Data datasets (MED-A) were filled by local DRST data managers. Relevant HCT outcome variables were evaluated by uni- and multivariate statistical analysis.

RESULTS

Median age of enrolled 33 patients was 51 years with a post allo-HCT median follow-up of 7.1 years of surviving patients. At time of HCT 24/33 patients had chemosensitive disease. In 24/33 patients reduced intensity conditioning (RIC) was used. Estimated 1, 2, 5-year overall survival (OS) and event-free survival rates were 49/39/33, and 33/30/24%. Cumulative 100 days non-relapse mortality was 25%. Chemosensitive disease, RIC, and limited chronic GvHD were identified as independent prognostic factors for OS.

CONCLUSIONS

Allo-HCT offers the chance of cure for tFL.

Novel acquisitions on biology and management of transformed follicular lymphoma

Follicular lymphoma (FL) generally has an indolent clinical course, but in some patients, a histological transformation (HT) into aggressive entities may take place and often lead to a poorer survival. The rituximab era has seen an improved outcome of FL, including those with HT. The current treatment strategies for transformed FL are based on immunochemotherapy for the cases with HT at the time of diagnosis or as the first event after watchful waiting. Patients transforming after prior treatment of FL usually benefit from autologous stem cell transplant. Unfortunately, early assessment of the transformation risk remains elusive. Recent studies delved the mechanisms of HT, showing that this is a complex process, resulting from a number of epigenetic and genetic lesions occurring in the tumour cell population as well as progressive changes in the tumour microenvironment. This novel knowledge has prompted clinical investigations on a variety of new therapeutic strategies.

Development of follicular lymphoma after treatment of diffuse large B-cell lymphoma: two case reports with review of literature

Diffuse large B-cell lymphoma (DLBCL) is one of the most frequent subtypes of aggressive lymphomas, which can be transformed lymphoma that mostly develops from other types of lymphoma. Cases of DLBCL arising developing after the initial diagnosis of follicular lymphoma (FL) have been reported. However, until now, little few studies have been reported were conducted on the patients with DLBCL and with subsequent development of FL in patients with DLBCL. Here we presented this study with two rare cases of, namely, FL and Composite concurrently occurs with DLBCL and FL developing after the initial diagnosis of DLBCL. In order to investigate the clinical and molecular features of patients with DLBCL and FL, we also reviewed the literature on FL patients with FL developing DLBCL, and patients with composite FL and DLBCL.

[Allogeneic haematopoietic cell transplantation for indolent lymphomas: Guidelines from the Francophone Society Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic hematopoietic cell transplantation is a potentially curative option, this is true particularly the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic hematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This paper specifically reports on our conclusions regarding indolent lymphomas, mainly follicular lymphoma and chronic lymphocytic leukemia.

Microfluidic Sorting of Cells by Viability Based on Differences in Cell Stiffness

The enrichment of viable cells is an essential step to obtain effective products for cell therapy. While procedures exist to characterize the viability of cells, most methods to exclude nonviable cells require the use of density gradient centrifugation or antibody-based cell sorting with molecular labels of cell viability. We report a label-free microfluidic technique to separate live and dead cells that exploits differences in cellular stiffness. The device uses a channel with repeated ridges that are diagonal with respect to the direction of cell flow. Stiff nonviable cells directed through the channel are compressed and translated orthogonally to the channel length, while soft live cells follow hydrodynamic flow. As a proof of concept, Jurkat cells are enriched to high purity of viable cells by a factor of 185-fold. Cell stiffness was validated as a sorting parameter as nonviable cells were substantially stiffer than live cells. To highlight the utility for hematopoietic stem cell transplantation, frozen samples of cord blood were thawed and the purity of viable nucleated cells was increased from 65% to over 94% with a recovery of 73% of the viable cells. Thus, the microfluidic stiffness sorting can simply and efficiently obtain highly pure populations of viable cells.

The role of stem-cell transplantation in the treatment of marginal zone lymphoma

High-dose chemotherapy and autologous stem-cell transplantation (ASCT) is standard therapy in relapsed/refractory aggressive lymphoma. The optimal therapy of relapsed/refractory disseminated marginal-zone lymphoma (MZL) has not been defined. Limited data on ASCT in this setting suggests outcomes are similar to what is expected in follicular lymphoma. International guidelines suggest that ASCT should be considered in follicular lymphoma in second or subsequent remission, in particular in high-risk disease, or following disease transformation. These guidelines can be extrapolated to MZL. ASCT is not considered curative but a subset of patients achieve very long remissions. The major concern is the occurrence of secondary malignancies possibly related to total-body irradiation. Allogeneic SCT is usually considered after failure of ASCT, but can also be considered upfront in younger patients seeking curative approach. The introduction of novel/targeted therapies may change the role and timing SCT may have in the treatment algorithm of indolent lymphomas.

Histological transformation to diffuse large B-cell lymphoma in patients with Waldenström macroglobulinemia

Histological transformation to diffuse large B-cell lymphoma (DLBCL) rarely occurs in patients with Waldenström Macroglobulinemia (WM). We identified 20 patients out of a cohort of 1,466 WM patients who experienced histologic transformation. The 5, 10, and 15-year cumulative incidence rates were 1, 2.4, and 3.8%, respectively. Approximately half of the patients were naive to nucleoside analogues, and a quarter were previously untreated for WM at the time of transformation. More than 80% of patients presented with extranodal involvement, 65% with high IPI scores. DLBCL cells did not express CD10 but expressed BCL6 and BCL2. All patients were treated with chemoimmunotherapy. The median survival from histological transformation was 2.7 years. The median overall survival was shorter for transformed patients versus those who did not transform (estimated 9 vs. 16 years; P = 0.09). Histological transformation to DLBCL is rare, and is associated with inferior survival in WM. Am. J. Hematol. 91:1032-1035, 2016. © 2016 Wiley Periodicals, Inc.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

Risk Factors and Outcomes for Patients With Follicular Lymphoma Who Had Histologic Transformation After Response to First-Line Immunochemotherapy in the PRIMA Trial

Purpose

To study the outcome of histologic transformation (HT) in a large prospective cohort of patients with follicular lymphoma (FL) who previously responded to immunochemotherapy.

Patients and Methods

After a median 6-year follow-up of 1,018 randomly assigned patients from the PRIMA trial, disease progression was observed in 463 patients, 194 of whom had histologic documentation.

Results

Forty patients had histology consistent with HT, and 154 had untransformed FL (median time to recurrence, 9.6 v 22.8 months, respectively; P = .018). Thirty-seven percent of biopsies performed during the first year of follow-up showed HT corresponding to 58% of all HTs. Altered performance status, anemia, high lactate dehydrogenase level, “B” symptoms, histologic grade 3a, and high Follicular Lymphoma International Prognostic Index scores at diagnosis were identified as HT risk factors. Response (complete v partial) to immunochemotherapy or rituximab maintenance had no impact on the risk of HT. After salvage treatment, patients with HT had less frequent complete response (50.3% v 67.4%; P = .03) and more disease progression (28.2% v 9.6%; P < .001) than patients without HT. Estimated overall survival for the patients with HT was poorer (median, 3.8 v 6.4 years; hazard ratio, 3.9; 95% CI, 2.2 to 6.9). Autologous stem cell transplantation improved the outcomes of patients with HT (median overall survival, not reached v 1.7 years) but not of patients with persistent FL histology.

Conclusion

HT in patients with FL who previously responded to immunochemotherapy is an early event associated with a poor outcome that may deserve intensive salvage with autologous stem cell transplantation. These data emphasize the necessity for biopsy at the first recurrence of FL.

Treatment of patients with transformed lymphoma

Histologic transformation (HT) is a frequent event in the clinical course of patients with indolent lymphoma. Most of the available data in the literature comes from studies on transformation of follicular lymphoma (FL), as this is the most common indolent lymphoma; however, HT is also well documented following small lymphocytic lymphoma/chronic lymphocytic leukaemia (SLL/CLL), lymphoplasmacytic lymphoma (LPL), or marginal zone lymphoma (MZL), amongst other types of lymphoma, albeit most of the studies on transformation in these subtypes are case reports or short series. The outcome of patients with HT has traditionally been considered dismal with a median overall survival (OS) of around 1 year in most of the published studies. This prompted many authors to include stem cell transplant (SCT) as part of the treatment strategy for young and fit patients with HT. However, recent articles suggest that the outcome of patients with transformed lymphoma might be improving, questioning the need for such intensive therapies. The management of patients with HT is challenged by the heterogeneity of the population in terms of previous number and type of therapy lines and from their exclusion from prospective clinical trials. This review will examine whether the advent of new therapies has impacted on the prognosis of HT and on current treatment strategies.

Salvage chemotherapy and autologous stem cell transplantation for transformed indolent lymphoma: a subset analysis of NCIC CTG LY12

The treatment of transformed indolent lymphoma (TRIL) often includes salvage chemotherapy (SC) and autologous stem cell transplant (ASCT). NCIC CTG LY12 is a randomized phase 3 trial comparing gemcitabine, dexamethasone, and cisplatin (GDP) with dexamethasone, cytarabine, and cisplatin (DHAP) before ASCT. This analysis compares the results of SC and ASCT for TRIL with de novo diffuse large B-cell lymphoma (DLBCL). Six-hundred nineteen patients with relapsed/refractory aggressive non-Hodgkin lymphoma were randomized to GDP or DHAP; 87 patients (14%) had TRIL and 429 (69%) had DLBCL. The response rate to SC was 47% in TRIL and 45% in DL (P = .81). Transplantation rates were similar: TRIL 53% and DL 52% (P = 1.0). With a median follow-up of 53 months, 4 year overall survival was 39% for TRIL and 41% for DL (P = .78); 4 year event-free survival (EFS) was 27% for TRIL and 27% for DL (P = .83). Post-ASCT, 4-year EFS was 45% for TRIL and 46% for DL. Histology (TRIL or DL) was not a predictor of any outcome in multivariate models. Patients with relapsed or refractory TRIL and DLBCL have similar outcomes with SC and ASCT; this therapy should be considered the standard of care for patients with TRIL who have received prior systemic chemotherapy. NCIC CTG LY12 is registered at ClinicalTrials.gov as #NCT00078949.

Sequential therapy combining clofarabine and T-cell-replete HLA-haploidentical haematopoietic SCT is feasible and shows efficacy in the treatment of refractory or relapsed aggressive lymphoma

Prognosis is poor for patients with biologically aggressive Non-Hodgkin lymphoma (NHL), refractory to chemotherapy or relapsed after autologous transplantation, especially when no disease control before allogeneic transplantation is achieved. In 16 patients (median age 53, median prior regimes 5) with relapsed or refractory non-remission NHL, we analysed retrospectively the efficacy of a sequential therapy comprising clofarabine re-induction followed by a reduced-intensity conditioning with fludarabine, CY and melphalan, and T-cell-replete HLA-haploidentical transplantation. High-dose CY was utilized post-transplantation. All patients engrafted. Early response (day +30) was achieved in 94%. Treatment-related grade III-IV toxicity occurred in 56%, most commonly transient elevation of transaminases (36%), while there was a low incidence of infections (19% CMV reactivation, 19% invasive fungal infection) and GVHD (GVHD: acute III-IV: 6%; mild chronic: 25%). One-year non-relapse mortality was 19%. After a median follow-up of 21 months, estimated 1- and 2-year PFS was 56 and 50%, respectively, with 11 patients (69%) still alive after 2 years. In summary, sequential therapy is feasible and effective and provides an acceptable toxicity profile in high-risk non-remission NHL. Presumably, cytotoxic reinduction with clofarabine provides enough remission time for the graft-versus lymphoma effect of HLA-haploidentical transplantation to kick in, even in lymphomas that are otherwise chemo-refractory.

What is the role of autologous transplant for lymphoma in the current era?

The role of autologous hematopoietic stem cell transplantation (ASCT) in the management of non-Hodgkin's lymphoma (NHL) is evolving, in the era of novel agents. Multiple histologies and remission stages have been impacted with changing outcomes. In the 1990s, ASCT could cure 50% of relapsed chemosensitive aggressive NHL; now the percentage maybe as low as 20% for patients relapsing within 1 year of completing rituximab-containing induction. Yet recent trials have clarified the value of first remission ASCT for high-grade NHL, the utility of augmented preparative regimens, the efficacy of ASCT in primary CNS lymphoma and in the elderly and analyses have defined strategies to reduce transplant related myeloid malignancies. In addition, optimizing nontransplant induction therapy for mantle cell and double-hit NHL is leading to improved outcomes and a re-examination of the use of ASCT in first complete remission. Caution is needed, however, as delaying transplants may mean that patients will need more morbid allogeneic transplants to achieve long-term control of refractory disease. As an alternative, maintenance therapy trials to improve ASCT outcome in high-risk patients are starting, based on the efficacy of lenolidomide and brentuximab in myeloma and Hodgkin's lymphoma, respectively. In addition, efforts to define early high-risk patients by minimal residual disease (MRD) assessments and genetic profiling, are beginning even for those with "indolent" phenotypes not currently autotransplanted. These efforts should not only refine but also enhance the value of early potentially curative ASCT, especially if novel agents only delay but do not prevent relapse for patients with NHL.

Transformed follicular non-Hodgkin lymphoma

Histologic transformation of follicular lymphoma to an aggressive non-Hodgkin lymphoma is a critical biologic event with profound implications on the natural history of this otherwise indolent disease. Recent insights into the genetic and epigenetic basis of transformation have been described, with the recognition of pivotal events governing the initiation and persistence of tumor evolution. Outcomes of patients with transformed lymphoma have historically been poor; however, several studies in the rituximab era suggest that survival may be more favorable than previously recognized. This review highlights our current understanding of transformed follicular lymphoma biology and pathogenesis, current treatment, and future directions.