High-dose therapy with autologous haematopoietic support in patients with transformed follicular lymphoma: a study of 27 patients from a single centre

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.

Similar prognosis of transformed and de novo diffuse large B-cell lymphomas in patients treated with immunochemotherapy

BACKGROUND

The prognosis of diffuse large B-cell lymphomas (DLBCL) transformed from indolent lymphoma (TL) has been considered poorer than that of de novo DLBCL. However, it seems to have improved since the introduction of rituximab.

PATIENTS AND METHODS

We compared the characteristics (including the cell-of-origin), and the prognosis of 29 patients with TL and 101 with de novo DLBCL treated with immunochemotherapy.

RESULTS

Patients with TL and de novo DLBCL had similar characteristics. All TL cases evolving from follicular lymphoma were germinal-center B-cell-like, while those TL from marginal zone lymphoma or chronic lymphocytic leukemia were non-germinal-center B-cell-like. The complete response rate was similar in TL and de novo DLBCL (62 vs. 66%, P=.825). The 5-year overall and progression-free survival probabilities (95% CI) were 59% (40-78) and 41% (22-60) for TL and 63% (53-73) and 60% (50-70) for de novo DLBCL, respectively (P=.732 for overall survival and P=.169 for progression-free survival).

CONCLUSION

In this study, the prognosis of TL and de novo DLBCL treated with immunochemotherapy was similar. The role of intensification with stem cell transplantation in the management of TL may be questionable in the rituximab era.

Consolidative Radioimmunotherapy After Chemoimmunotherapy in Patients With Histologic Transformation of Indolent Non-Hodgkin Lymphoma

INTRODUCTION

Histologic transformation (HT) of indolent non-Hodgkin lymphomas is an event that results in considerable morbidity and mortality. The introduction of chemoimmunotherapy regimens has resulted in an improvement in the management of this disease, and consolidation of responses with autologous stem cell transplantation appears efficacious. Many patients are not eligible for high-dose therapy, however. Radioimmunotherapy (RIT) has demonstrated single-agent efficacy in HT and can be used safely as consolidation after chemoimmunotherapy. For these reasons, RIT consolidation after chemoimmunotherapy induction has been our standard treatment approach at the University of Rochester for patients with HT who were ineligible for autologous stem cell transplantation.

PATIENTS AND METHODS

A retrospective cohort study was performed to describe the clinical outcomes of these patients. Twenty-one patients were identified who received RIT consolidation. The Kaplan-Meier method was used to estimate the distributions of overall survival and progression-free survival. Comparisons were made between patients with pathologic HT and the combination of clinical HT and composite lymphoma using the log-rank test to compare survival curves.

RESULTS

The median overall survival of the cohort was 84 months, and progression-free survival was 38 months. The major toxicity was myelosuppression, and 2 deaths were attributed to therapy. One case of therapy-related acute myeloid leukemia was noted.

CONCLUSION

In a population of patients ineligible for high-dose therapy with autologous stem cell support, consolidation of response to chemoimmunotherapy with RIT was well tolerated and should be considered in patients with disease responsive to induction therapy.

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.

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.

High dose chemotherapy with autologous stem cell transplant for patients with transformed B-cell non-Hodgkin lymphoma in the rituximab era

High dose chemotherapy with autologous stem cell transplant (HD-ASCT) is a recommended procedure for patients with transformed indolent B-cell lymphoma from the pre-rituximab era. In this retrospective single-center study, we present our experience with HD-ASCT in patients with histologically verified transformed indolent B-cell lymphoma in the rituximab era. Forty-two patients were included, of whom 28 with chemosensitive disease proceeded to HD-ASCT. Twenty patients (71%) achieved a complete response (CR) and five (18%) a partial response (PR) after HD-ASCT. With a median observation time of 49 months for the survivors, the median progression-free survival (PFS) and overall survival (OS) for patients with HD-ASCT were 39 months and 57 months, respectively. Patients who were rituximab-naive at transformation had a significantly better OS compared to patients previously treated with rituximab, both in the whole patient cohort and among the HD-ASCT-treated patients (p = 0.036 and p = 0.039, respectively). Furthermore, male sex influenced survival negatively, whereas time from diagnosis to transformation was positively associated with survival, both with borderline significance, in HD-ASCT-treated patients. In conclusion, HD-ASCT remains an effective treatment for transformed indolent lymphomas in the rituximab era.

Rates and outcomes of follicular lymphoma transformation in the immunochemotherapy era: a report from the University of Iowa/MayoClinic Specialized Program of Research Excellence Molecular Epidemiology Resource

PURPOSE

This study sought to characterize transformation incidence and outcome for patients with follicular lymphoma (FL) in a prospective observational series begun after diffusion of rituximab use.

PATIENTS AND METHODS

Patients with newly diagnosed FL were prospectively enrolled onto the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource from 2002 to 2009. Patients were actively followed for re-treatment, clinical or pathologic transformation, and death. Risk of transformation was analyzed via time to transformation by using death as a competing risk.

RESULTS

In all, there were 631 patients with newly diagnosed grade 1 to 3a FL who had a median age at enrollment of 60 years. At a median follow-up of 60 months (range, 11 to 110 months), 79 patients had died, and 60 patients developed transformed lymphoma, of which 51 were biopsy proven. The overall transformation rate at 5 years was 10.7%, with an estimated rate of 2% per year. Increased lactate dehydrogenase was associated with increased risk of transformation. Transformation rate at 5 years was highest in patients who were initially observed and lowest in patients who initially received rituximab monotherapy (14.4% v 3.2%; P = .021). Median overall survival following transformation was 50 months and was superior in patients with transformation greater than 18 months after FL diagnosis compared with patients with earlier transformation (5-year overall survival, 66% v 22%; P < .001).

CONCLUSION

Follicular transformation rates in the immunochemotherapy era are similar to risk of death without transformation and may be lower than reported in older series. Post-transformation prognosis is substantially better than described in older series. Initial management strategies may influence the risk of transformation.

Autologous and Allogeneic Stem-Cell Transplantation for Transformed Follicular Lymphoma: A Report of the Canadian Blood and Marrow Transplant Group

Purpose

To determine whether autologous (auto) or allogeneic (allo) stem-cell transplantation (SCT) improves outcome in patients with transformed follicular lymphoma compared with rituximab-containing chemotherapy alone.

Patients and Methods

This was a multicenter cohort study of patients with follicular lymphoma and subsequent biopsy-proven aggressive histology transformation. Patient, treatment, and outcome data were collected from each transplantation center and combined for analysis. A separate control group was composed of patients with transformation treated with rituximab-containing chemotherapy but not SCT. The primary end point was overall survival (OS) after transformation.

Results

One hundred seventy-two patients were identified: 22 (13%) treated with alloSCT, 97 (56%) with autoSCT, and 53 (31%) with rituximab-containing chemotherapy. Five-year OS after transformation was 46% for patients treated with alloSCT, 65% with autoSCT, and 61% with rituximab-containing chemotherapy (P = .24). Five-year progression-free survival (PFS) after transformation was 46% for those treated with alloSCT, 55% with autoSCT, and 40% with rituximab-containing chemotherapy (P = .12). In multivariate analysis, patients treated with autoSCT had improved OS compared with those who received rituximab-containing chemotherapy (hazard ratio [HR], 0.13; 95% CI, 0.05 to 0.34; P < .001). On the other hand, there was no OS difference between those treated with alloSCT and rituximab-containing chemotherapy (HR, 0.44; 95% CI, 0.16 to 1.24; P = .12). OS and PFS after SCT were similar between those treated with autoSCT and alloSCT. Five-year transplantation-related mortality was 23% for those treated with alloSCT and 5% for autoSCT.

Conclusion

Patients undergoing autoSCT had better outcomes than those treated with rituximab-containing chemotherapy alone. AlloSCT did not improve outcome compared with rituximab-containing chemotherapy and was associated with clinically significant toxicity.

High-dose therapy and autologous stem cell transplant for transformed non-Hodgkin lymphoma in the rituximab era

The impact of rituximab on the outcome of high-dose therapy and autologous stem cell transplant (HD-ASCT) for transformed non-Hodgkin lymphoma (NHL) has not been previously described. We analyzed 18 consecutive patients with indolent NHL who transformed to diffuse large B-cell lymphoma (DLBCL), received rituximab-containing therapy either before or after transformation and underwent subsequent HD-ASCT. With a median follow-up of 40 months, the 2-year progression-free survival (PFS) was 59% and the 2-year overall survival (OS) was 82%. Six patients did not receive rituximab pre-transformation. This group had a significantly better PFS at 2 years post-HD-ASCT compared to 12 patients who were exposed to rituximab pre-transformation (p = 0.03). HD-ASCT remains an effective therapeutic option for transformed NHL in the rituximab era. However, patients exposed to rituximab pre-transformation appear to have inferior HD-ASCT outcomes, and thus may benefit from novel conditioning and maintenance regimens in the setting of HD-ASCT.

Treatment options for transformed lymphoma: incorporating allogeneic stem cell transplantation in a multimodality approach

Transformed non-Hodgkin lymphoma (TL) arising from follicular lymphoma carries a poor prognosis, and the median survival time after transformation is approximately 10 to 12 months. Standard chemotherapy and radioimmunotherapy have offered promising responses; however, the duration of response does not appear to last long. Several studies evaluating the role of autologous stem cell transplantation (auto-SCT) as a salvage regimen have been reported, and a subset of patients benefit from this modality of treatment. With an improvement in supportive care, outcome after allogeneic stem cell transplantation (allo-SCT) has been improved significantly over past decades; however, very limited data are available for TL. In the era of emerging novel therapies, the actual timing, optimal conditioning regimens, and long-term impact of the type of stem cell transplantation (auto-SCT vs allo-SCT) is unclear. This review addresses the approaches to the management of patients with TL.

Transformation of follicular lymphoma

Histological transformation of follicular lymphoma (FL) to a more aggressive non-Hodgkin's lymphomas is a pivotal event in the natural history of FL and is associated with poor outcome. While commonly observed in clinical practice and despite multiple studies designed to address its pathogenesis, the biology of this process represents an enigma. In this chapter we present a state of the art review summarizing the definition of histologic transformation, its incidence, pathogenesis, clinical manifestations, treatment and outcome. Furthermore, we specifically emphasize gaps in our knowledge that should be addressed in future studies.

Transformation of Indolent B-Cell Lymphomas

Histologic transformation (HT) to an aggressive lymphoma is a well-described event in the natural history and clinical course of patients with so-called indolent lymphomas. This phenomenon has been studied most extensively in patients with follicular lymphoma and subsequent transformation to a diffuse large B-cell lymphoma, with little literature on HT in nonfollicular lymphomas. Despite a considerable body of information on the pathologic and molecular events associated with HT, its pathogenesis has remained elusive and the molecular information available has not been translated into clinical advances. It remains unclear if there is already a predisposition to HT and whether this can be detected at the time of diagnosis. The rituximab era has been characterized by a significant improvement in the prognosis of patients with B-cell lymphomas, but HT remains one of the most important challenges in the management of patients with indolent lymphoma, the difficulties starting with the diagnosis and definition of HT and ending with the appropriate management and treatment of the event. Going forward, it is crucial to incorporate HT as a major end point in clinical trials and to include patients with HT as subject of such studies if we are to see meaningful progress in the future.

The incidence, natural history, biology, and treatment of transformed lymphomas

Treatment of patients with transformed lymphoma presents a significant challenge to the practicing physician. Indeed, the transformation of follicular lymphoma to a more aggressive histology is inherent to the biology of this disease and is often associated with an aggressive clinical course, resulting in a poor prognosis. Recent population-based studies have better defined the incidence of this event, and recent laboratory studies have defined the molecular and immunological processes associated with transformation. These studies will be discussed in this review, as will the treatment options for these patients.

Economic burden of follicular non-Hodgkin's lymphoma

Follicular non-Hodgkin's lymphoma (FNHL), a slow-growing cancer of the immune system, constitutes about 15-30% of all incident non-Hodgkin's lymphoma in developed countries. Its incidence is rising worldwide. Patients can live many years, but FNHL is considered incurable. We systematically reviewed the English-language MEDLINE-indexed and non-indexed economic literature published in the past 10 years on FNHL, identifying 23 primary economic studies. The economic burden of FNHL is significant, but available data are generally limited to retrospective considerations of hospital-based direct treatment costs, with little information available regarding societal cost of illness. Most direct cost information originates from the US, with one estimate of $US36 000 for the per-patient incremental cost of FNHL care during the first year following diagnosis. The most studied treatment is rituximab, which may offer similar overall costs to fludarabine considering higher resource use with fludarabine complications. Nearly all cost-effectiveness models identified by this review evaluated rituximab for relapsed/refractory FNHL responding to chemotherapy induction. Rituximab is supported as a cost-effective addition to standard chemotherapy by two models in the UK and one in the US, as maintenance therapy instead of stem-cell transplant by one UK model, and as maintenance therapy instead of observation alone by one model each in France, Spain and Canada. The UK National Institute for Health and Clinical Excellence updated guidance on rituximab in February 2008, concluding that it is cost effective when added to induction chemotherapy, and when used as maintenance therapy. No studies of per-patient or national indirect costs of illness were identified, with the only study of indirect costs a Canadian survey documenting lost work productivity. Across all study types identified by our review, the most common focus was on the direct costs of rituximab. As new treatments for FNHL come to market, more real-life cost data are imperative to calculate their relative cost effectiveness.

The incidence, natural history, biology, and treatment of transformed lymphomas

Treatment of patients with transformed lymphoma presents a significant challenge to the practicing physician. Indeed, the transformation of follicular lymphoma to a more aggressive histology is inherent to the biology of this disease and is often associated with an aggressive clinical course, resulting in a poor prognosis. Recent population-based studies have better defined the incidence of this event, and recent laboratory studies have defined the molecular and immunological processes associated with transformation. These studies will be discussed in this review, as will the treatment options for these patients.

Follicular lymphomas

Follicular lymphomas constitute approximately 30% of all non-Hodgkin lymphomas. These lymphomas are characterized by at least partially follicular growth pattern, but diffuse areas may be present. The proportions of follicular or diffuse areas vary also from case to case, which seems to be associated with prognosis. Follicular lymphomas should not be divided into distinct subtypes, but rather shows a continuous gradation in the number of large cells. On the bases of this grading, three groups have been defined: grades 1-3. There is a consensus that grade 3 follicular lymphomas, namely grade 3b, should be discriminated from lower-grade cases. The cells of follicular lymphomas express surface immunoglobulin, more frequently IgM+/-IgD>IgG>IgA, B-cell-associated antigens, CD10+/-; they are CD5-, CD23-/+, CD43-, and CD11c-. Follicular lymphomas express bcl-2 proteins, which is useful in distinguishing reactive from neoplastic follicles. t(14;18) is present in 70-95% of follicular lymphomas, involving rearrangement of bcl-2 gene. Clinical behavior of follicular lymphomas is heterogeneous and differs according to the histologic grade and extension of disease. Moreover, the evaluation of these malignancies is conditioned by therapeutic decision, which is also determined by main prognostic factors. The International Prognostic Index for aggressive lymphomas is not optimal for follicular lymphomas. Conversely, the Italian Lymphoma Intergroup Index and, more recently, the Follicular Lymphoma International Prognostic Index (FLIPI), designed in pre-rituximab era, seem to correlate well with outcome. Several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with follicular lymphoma. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histologic grade, tumor burden, and risk-predicting factors.

A 15-Year Analysis of Early and Late Autologous Hematopoietic Stem Cell Transplant in Relapsed, Aggressive, Transformed, and Nontransformed Follicular Lymphoma

Autologous stem cell transplant (ASCT) has been shown to be an effective treatment for follicular lymphoma (FL). We explored our experience in ASCT for FL among all patients treated over a 15-year period from diagnosis through their entire treatment history including relapse post ASCT. All patients who underwent an unpurged ASCT for relapsed, advanced FL between June 1990 and December 2000 were analyzed. After salvage therapy they received melphalan/etoposide/total body irradiation, BCNU, etoposide, cytarabine, melphalan (BEAM), or cyclophosphamide BCNU etoposide (CBV) as conditioning for the ASCT. One hundred thirty-eight patients with a median age of 48 years and a median follow-up of 7.6 years were analyzed. The majority were of the subtype grade 1, nontransformed (FL-NT), having had 1 prior chemotherapy. The progression-free (PFS) and overall survival (OS) of the FL-NT at 10 years were 46% and 57%, respectively, and at 5 years for the transformed (FL-T) were 25% and 56%, respectively, of which only the PFS was significantly different (P=.007). The median OS from diagnosis was 16 years for the FL-NT. ASCT positively altered the trend of shorter remissions with subsequent chemotherapies, and there was no difference in OS between those who had 1, 2, or >2 chemotherapies prior to ASCT. Salvage therapy for relapse post ASCT was effective (OS>1 year) in a third of patients. Unpurged ASCT is an effective tool in the treatment of relapsed, aggressive FL-NT and FL-T, is superior to retreatment with standard chemotherapy, is effective at various stages of treatment, is likely to have a beneficial influence on the natural history of this disease, and the disease is amenable to salvage therapy post-ASCT relapse.

Feasibility and safety of autotransplants with noncryopreserved marrow or peripheral blood stem cells: a systematic review

The objective of this systematic review is to examine the feasibility and safety of autologous noncryopreserved stem-cell transplants. This technique avoids the cost of establishing and maintaining a cryopreservation facility and may be of value for transplant centers in regions with limited economic resources. The primary outcome was the graft failure rate. In addition, a detailed description of the high-dose therapy regimens employed was undertaken. Secondary outcomes were transplant-related mortality and neutrophil and platelet engraftments times. Sixteen well-conducted nonrandomized studies met the eligibility criteria. Only two cases of graft failure (0.36%) occurred among 560 assessable patients receiving high-dose therapy and autotransplant for non-Hodgkin's lymphoma, Hodgkin's lymphoma, multiple myeloma, germ-cell tumors and acute leukemias. The most traditional high-dose schedules were used, although often modified to shorter regimens. High-dose melphalan appeared especially useful given its short half-life and was used to treat multiple myeloma by most groups. Secondary outcomes were comparable to those reported in the most relevant studies addressing standard (cryopreserved) autotransplant. According to this study, the use of autologous noncryopreserved hematopoietic progenitors to support patients undergoing high-dose therapy is feasible and safe.

The Follicular Lymphoma International Prognostic Index (FLIPI) and the histological subtype are the most important factors to predict histological transformation in follicular lymphoma

BACKGROUND

Histological transformation (HT) is a well-known event in patients with follicular lymphoma (FL) conferring an unfavorable prognosis. The aim of the study was to analyze incidence and risk factors for HT in a large series of FL patients.

PATIENTS AND METHODS

276 patients (median age: 54 years; M139/F137) diagnosed with FL (42% grade 1, 51% 2, 7% 3) in a single institution were studied. Initial treatment consisted of combined chemotherapy in most cases. Median survival was 11.3 years. Main clinic and biological variables were assessed for HT and survival.

RESULTS

30 of 276 patients (11%) presented HT after a median follow-up of 6.5 years, with a risk of 15% and 22% at 10 and at 15 years, respectively. All HT corresponded to diffuse large B-cell lymphoma (DLBCL). Grade 3 histology, nodal areas >4, increased LDH and beta(2)-microglobulin, and high-risk IPI and FLIPI were associated with HT. In multivariate analysis, grade 3 histology and FLIPI retained prognostic significance. Only FLIPI predicted HT in grade 1-2 patients. 28 patients received salvage treatment for HT, with a CR rate of 52%. Median survival from transformation was 1.2 years, with 6/13 CR patients being alive >5 years after HT.

CONCLUSION

FLIPI and histology were the most important variables predicting HT. Upon HT, only patients achieving CR reached prolonged survival, thus emphasizing the need for effective therapies once this event occurs.

Long-term event-free survivors after high-dose therapy and autologous stem-cell transplantation for low-grade follicular lymphoma

Although follicular lymphoma (FL) is generally responsive to conventional-dose chemotherapy, improved survival in patients with this disease has been difficult to demonstrate. High-dose chemo/radiotherapy followed by autologous stem-cell transplantation (ASCT) can improve response rates, although its effects on survival remain controversial. Between 1990 and 2003, we transplanted 49 patients with low-grade FL at our institution. Twenty-two patients (45%) had undergone histologic transformation at the time of ASCT. In all, 44 patients (90%) had relapsed disease and five patients (10%) were resistant to chemotherapy at the time of transplantation. After ASCT, 30 patients (61%) were in complete remission (CR). The median overall survival (OS) has not been reached, while the median event-free survival (EFS) is 2.4 years. At a median follow-up of 5.5 years (longest 12.4 years), a plateau has been reached with 56% of patients remaining alive, and 35% event-free. ASCT was well tolerated except for two (4%) treatment-related deaths. In multivariable analysis, CR after ASCT and age less than 60 years are the best predictors of EFS and OS. ASCT is thus a safe therapeutic approach in FL, resulting in long-term EFS and OS for some patients, even with transformed disease.

A limited role for TP53 mutation in the transformation of follicular lymphoma to diffuse large B-cell lymphoma

The role of TP53 mutation in transformation of follicular lymphoma (FL) to diffuse large B-cell lymphoma (t-FL) was examined in a panel of 91 lymph node biopsies derived from 29 patients pre- and post-transformation. The entire TP53 coding sequence was screened and immunocytochemistry performed to determine expression of p53 and its key regulator MDM2. A total of 10 mutations were detected in eight patients (28%), although none were present at FL diagnosis. Mutations were not detected solely at the time of transformation; in three patients, mutated TP53 arose in at least one antecedent FL sample (6 months, 2.5 years and 4 years prior to transformation). Loss of heterozygosity at the TP53 locus occurred in 2/20 informative patients (only in t-FL samples). p53 staining was positive in 82% (9/11) of available biopsies with a missense mutation, and negative in 71% (45/63) with wtTP53. MDM2 expression was significantly higher in t-FL samples (mean 72% positive; 95% confidence interval (95% CI) 68-76%) than FL (mean 58% positive; 95% CI 54-62%) (P<0.001) but did not correlate with TP53 status. TP53 mutation has only a limited role in the transformation of FL, exerting a heterogeneous influence upon phenotypic change. In contrast, dysregulation of MDM2 is frequent and may provide a more rational therapeutic target..

Concurrent administration of high-dose rituximab before and after autologous stem-cell transplantation for relapsed aggressive B-cell non-Hodgkin's lymphomas

PURPOSE

We investigated the efficacy and safety of administering high-dose rituximab (HD-R) in combination with high-dose carmustine, cytarabine, etoposide, and melphalan chemotherapy and autologous stem-cell transplantation (SCT) in patients with recurrent B-cell aggressive non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Sixty-seven consecutive patients were treated. Rituximab was administered during stem-cell mobilization (1 day before chemotherapy at 375 mg/m(2) and 7 days after chemotherapy at 1,000 mg/m(2)), together with granulocyte colony-stimulating factor 10 mug/kg and granulocyte-macrophage colony-stimulating factor 250 microg/m(2) administered subcutaneously daily. HD-R of 1,000 mg/m(2) was administered again days 1 and 8 after transplantation. The results of this treatment were retrospectively compared with those of a historical control group receiving the same preparative regimen without rituximab.

RESULTS

With a median follow-up time for the study group of 20 months, the overall survival rate at 2-years was 80% (95% CI, 65% to 89%) for the study group and 53% (95% CI, 34% to 69%) for the control group (P = .002). Disease-free survival was 67% (95% CI, 51% to 79%) for the study group and 43% (95% CI, 26% to 60%) for the control group (P = .004). The median time to recovery of absolute neutrophil count to >/= 500 cells/microL was 11 days (range, 8 to 37 days) for the rituximab group and 10 days (range, 8 to 17 days) for the matched control group (P = .001). However, infections were not significantly increased in patients treated with rituximab.

CONCLUSION

The results of this study suggest that using HD-R and autologous SCT is a feasible and promising treatment for patients with B-cell aggressive NHL.

Long-term follow-up after autologous hematopoietic stem cell transplantation for low-grade non-Hodgkin lymphoma

Autologous hematopoietic stem cell transplantation (AHSCT) in low-grade non-Hodgkin lymphoma (NHL) can result in a prolonged remission, although most patients eventually relapse and die of their disease. We report long-term outcomes of AHSCT for patients with relapsed low-grade NHL. Between May 1983 and 2001, 67 patients with relapsed or refractory stage III and IV low-grade NHL received an AHSCT at the University of Minnesota at a median of 2.3 years (range, 0.4-15.2 years) after diagnosis. At transplantation, 62 patients (92%) were in complete remission (CR) (6%) or partial remission (PR) (86%); 5 (8%) had resistant disease; and 9 (14%) had transformed to a higher-grade NHL. After AHSCT, 32 (49%) of 65 evaluable patients achieved CR, and 26 (40%) achieved PR. Overall survival (OS) was 50% (95% confidence interval [CI], 38%-62%) at 4 years and 33% (95% CI, 20%-46%) at both 10 and 18 years, whereas progression-free survival (PFS) was 28% (95% CI, 17%-39%) at 4 years, 18% (95% CI, 8%-28%) at 10 years, and 14% (95% CI, 4%-25%) at 18 years. Transplant-related mortality in the first 100 days was 3% (95% CI, 0%-7%). Relapse occurred in 62% (95% CI, 48%-75%) at 4 years and 72% (95% CI, 56%-87%) at 10 years. Eleven patients (16%) developed myelodysplastic syndrome/acute myeloid leukemia 1 to 8 years after AHSCT, and 3 (5%) developed solid tumors. In multiple regression analysis, the International Prognostic Index (IPI) score at transplantation was the most significant predictor for both OS and PFS. The median OS has not been reached in patients with an IPI score of 0 or 1 at transplantation (20 of 35 survive 2 to 18 years after AHSCT), whereas it was 2.3 and 1.6 years for IPI scores of 2 and 3, respectively ( P = .002). A good response (CR/PR) to AHSCT (relative risk [RR], 0.4; 95% CI, 0.2-0.9; P = .04) and age <50 years (RR, 0.5; 95% CI, 0.2-0.8; P = .01) were also independently significant predictors of good OS and PFS. We present mature follow-up data (median follow-up, 8 years; range, 2-18 years) of patients undergoing AHSCT for relapsed low-grade NHL and demonstrate extended OS and PFS. Very long-term remissions were seen in nearly 20% of patients. AHSCT remains promising, especially for patients with sensitive relapse and lower IPI scores. Recurrent lymphoma after AHSCT remains the major problem, and prolonged survival is further tempered by a significant risk of post-transplantation second malignancies, including myelodysplastic syndrome/acute myeloid leukemia and solid tumors.

Biology and Management of Histologic Transformation of Indolent Lymphoma

The evolution of indolent lymphomas to aggressive histologies, known as histologic transformation (HT), is a frequent occurrence for all subtypes of low grade B cell lymphoproliferative disorders. The risk of developing HT is approximately 3% per year for patients with indolent lymphoma. Clinically these present with a rapid change in the behavior of the disease, with evidence of a highly proliferative malignancy with a propensity to involve extranodal sites. The prognosis of patients following transformation is generally poor, with median survival of about 12 months. Recent studies suggest that the development of HT is very complex with the acquisition of multiple cytogenetic abnormalities in the low-grade lymphoma cells prior to HT. To date, there are no biologic or genetic parameters predictive of the development of HT. A myriad of genetic lesions have been identified in HT, and provide insight into its pathogenesis. These include genes regulating proliferation (C-MYC and C-MYC-regulated genes); control of the cell cycle (CDKN2a and CDKN2B); and programmed cell death (TP53, C-MYC, and BCL2). Gene expression profiling has been applied to the study of HT and has increased our understanding of the transformation process. There has been limited progress in the treatment of patients with HT. Conventional chemotherapy is generally of limited benefit, although a subset of patients are long-term survivors following high-dose therapy and autologous stem cell transplantation. The use of radioimmunotherapy and new agents targeting specific lesions or aberrant pathways may impact on the management of these aggressive diseases.

Stem cell transplantation in follicular lymphoma: progress at last?

Follicular non-Hodgkin's lymphomas usually present in advanced stage and although frequently are chemotherapy-sensitive remain incurable using conventional approaches. Treatment options are evolving rapidly and now include targeted therapies such as monoclonal antibodies. Recent studies, including the EBMTR-sponsored 'CUP Trial' (conventional Chemotherapy, Unpurged autograft, Purged autograft), demonstrate that for patients under age 60 years with recurrent chemotherapy-sensitive disease, autologous stem cell transplantation (ASCT) provides a survival benefit over conventional therapy. Allogeneic stem cell transplantation (alloSCT) has become a more effective option. Although incorporation of TBI into the preparative regimen may increase treatment-related mortality (TRM), relapses appear to be reduced compared to a chemotherapy-alone regimen. Reduced-intensity alloSCT procedures are now being performed at an increasing rate, in part due to a lower risk for TRM. Until more data are available, however, reduced-intensity alloSCT should be considered only in cases where myeloablative conditioning is contra-indicated. There are no clear means for choosing ASCT vs alloSCT, a decision influenced by the amount of residual tumor, disease-responsiveness, degree of marrow involvement and extent of prior chemotherapy. ASCT or alloSCT in first remission remains an investigational procedure. Future considerations include incorporation of novel preparative regimens, in vitro purging techniques, antilymphoma vaccines, post transplant immunotherapy and ex vivo-manipulated donor lymphocyte infusions.

The role of stem cell transplantation in the treatment of follicular lymphoma

Follicular lymphoma (FL) is highly sensitive to chemo- and radiotherapy. However, cure can not be achieved with conventional chemotherapy. Results from several large clinical trials indicate that 50-60% of patients treated with high dose chemo-/radiotherapy (HDT) and autologous blood stem cell transplantation (SCT) for relapse after standard chemotherapy have a 3-5-year chance of disease-free survival (DFS). Overall as well as disease-free survival are improved in patients with negative results in sensitive PCR assays for the disease-specific t(14;18) translocation in bone marrow (BM) or peripheral blood samples taken after transplantation. These data compare favourably to historical results with standard dose chemotherapy. The role of high dose therapy and autologous stem cell transplantation in the primary treatment of follicular lymphoma is presently addressed in randomized trials. Patients with refractory disease or relapsing from standard as well as high dose therapy can achieve long term complete remissions (CR) with allogeneic blood stem transplantation mainly due to the graft-versus-lymphoma effect of the donor immune system.

Transformed lymphoma: an Achilles' heel of non-Hodgkin's lymphoma

Transformed lymphoma has a reported incidence of 10-70% among patients with follicular lymphoma. Interpreting the wide-ranging estimates for incidence, survival, and effects of interventions from various studies is complicated by the use of different definitions of lymphoma transformation. Problems in defining histologic transformation will be addressed in this review. To date, there are no reliable markers of risk for transformation or factors predictive of survival. The prognosis for transformed lymphoma is generally poor, with most patients surviving only a few months, though some with limited disease that is chemosensitive may experience prolonged survival. Immunotherapy, particularly monoclonal antibodies and radioimmunoconjugates, holds promise but more experience is necessary. Approximately 200 patients are included in published series of autologous transplantation; of these, one-third remain disease free at 5 years, not dissimilar to reported outcomes for nontransformed disease. However, the treatment-related mortality is higher than in nontransformed disease, and there is a significant incidence of post-transplant myelodysplastic syndrome. The role of allogeneic transplant has yet to be pursued, but should be explored for its potential for a graft-versus-lymphoma effect. Advances in microarray gene analysis and biology may facilitate the understanding of mechanisms of transformation, development of a prognostic index and creation of tailored therapy.

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.

Genetic susceptibility to Hodgkin's disease and secondary neoplasias: FISH analysis reveals patients at high risk of developing secondary neoplasia

BACKGROUND

Cytotoxic drugs administered before high-dose therapy (HDT) represent a significant factor in the development of leukemic complications in patients with lymphoid malignancies. This retrospective study was used to detect evidence of abnormal therapy-related myelodysplasia/secondary acute myeloid leukaemia (tMDS/sAML) clones before HDT in a subset of patients who subsequently developed secondary neoplasia.

PATIENTS AND METHODS

230 patients with non-Hodgkin's lymphoma (NHL) underwent HDT comprising cyclophosphamide and total body irradiation (TBI) with autologous hematopoietic progenitor-cell support. Thirty-three patients have developed tMDS/sAML and 20 of these were screened for the presence of emerging therapy-related abnormalities before HDT. A further 24 patients without evidence of secondary neoplasia were screened using fluorescence in situ hybridisation (FISH).

RESULTS

Significant levels of abnormal cells were identified in 20/20 patients screened who have developed secondary neoplasia compared with only three of 24 patients in the HDT control group who have not. The latter three patients have since died.

CONCLUSIONS

The triple FISH assay was developed to detect loss of chromosomal material from 5q31, 7q22 and 13q14. It can potentially identify those patients at risk of alkylating agent-induced leukaemia before they proceed to HDT. Used in a prospective manner, the triple FISH assay could permit more informed clinical management.

Oral cyclophosphamide therapy for patients with residual or relapsed indolent-type lymphoma after initial treatment for aggressive lymphomas. A sub-group of patients with apparent transformed indolent lymphoma

Lymph node or bone marrow biopsy from sixty-one patients affected by aggressive non-Hodgkin lymphomas (NHL) were retrospectively evaluated to assess the histology at relapse. Eighteen cases (29.5%) were proven to have relapsed or persistent low-grade lymphoma after conventional therapy. In 5/18 patients association of low and high-grade lymphoma was detectable at diagnosis by bone marrow biopsy. In the remaining 13/18 no evidence of follicular lymphoma was detected at diagnosis. The outcome of these patients was compared to that of 43 patients relapsed without change in histology and treated by a second line therapy. Of these 43 patients, 13 were not responders (NR), 10 achieved a partial remission (PR) and 18 complete remission (CR). Two were lost during follow-up. The 18 patients with residual/relapsed indolent subtype received oral cyclophosphamide (100 mg/day for 15 days every month for six months): 3 of them had NR, 5 CR, and 10 PR. The overall survival (OS) median time was 39 months in low-grade resistant/relapsed patients and 20 months in patients with aggressive histology. OS at 24 months was 71 and 41%, respectively, (p < 0.02). Most of the patients with high-grade disease were refractory or relapsed after a median of five months, whereas cases with low-grade NHL showed a long lasting stable PR. We suggest that the higher grade patients with residual or relapsed low grade lymphoma were, in fact, transformed low-grade at diagnosis and, after removing the more aggressive component by chemotherapy, it is possible to manage these patients by conventional therapy for indolent lymphomas.

High-dose treatment with autologous haemopoietic progenitor cell support for large B-cell, follicular and mantle-cell lymphoma

The purpose of this chapter is to review the available information on the use of high-dose treatment (HDT) in large B-cell, follicular and mantle-cell lymphoma. The last 10 years have seen a dramatic increase in the number of patients receiving high-dose treatment with autologous haemopoietic progenitor cell support for non-Hodgkin's lymphoma. In patients with recurrent large B-cell lymphoma, HDT is now accepted as the 'standard of care', provided responsiveness to conventional chemotherapy at the time of recurrence has been demonstrated. In contrast, the situation in newly diagnosed patients is far from clear. Several phase III studies have been conducted, comparing conventional chemotherapy with either: the same treatment followed by HDT or an abbreviated number of cycles of conventional therapy followed by HDT. The results hitherto have not conclusively shown an advantage for HDT. In mantle-cell and follicular lymphoma, HDT should still be regarded as experimental. Current studies are evaluating the use of anti-CD20, given either as part of the treatment prior to HDT or as maintenance therapy. In view of the propensity for both of these illnesses to involve the bone marrow, a number of studies have addressed the question of in vitro treatment of the stem cell product. The advent of PCR analysis has made it possible to evaluate the significance of 'molecular remission'. In follicular lymphoma, there is a correlation between freedom from recurrence and persistent PCR negativity for bcl-2 rearrangement-containing cells in follow-up bone marrow samples.

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.

Clonal heterogeneity assessed by flow cytometry in B-cell lymphomas arising from germinal centers

Patients with mature follicular B-cell lymphomas develop aggressive non-Hodgkin lymphomas (NHLs) during disease progression. It is controversial whether most diffuse large B-cell lymphomas (DLBCLs) and Burkitt lymphomas (BLs) emerge as de novo lymphomas or from an original follicular lymphoma. To distinguish clonally related populations in aggressive NHL, we studied the immunophenotypic features of 18 consecutive samples from 16 patients. Three flow cytometric patterns were distinguished: (1) a homogeneous neoplastic population of large B cells with phenotypic features of follicular center cells; (2) 2 atypical populations of B cells, small monoclonal B cells, and large B cells with loss of some surface antigens; and (3) 2 clonal populations of small and large B cells sharing the same light-chain isotype. The 3 flow cytometric patterns were observed, respectively, in de novo DLBCL and BL, transformation into BL, and transformation into DLBCL. Flow cytometric data can provide valuable information about the natural history of NHL.

Autologous hematopoietic cell transplantation non-Hodgkin's lymphoma: 100 month follow-up

One hundred and ten adult patients with non-Hodgkin's lymphoma (NHL) received an autologous hematopoietic cell transplant (ABMT) from 1988 to 1993. All received a uniform preparative regimen of cyclophosphamide, BCNU and etoposide (CBV). Twenty-one percent had low grade histologies, 54% intermediate grade, and 25% high grade. Median follow-up of 48 survivors is 100 months. Kaplan-Meier 10 year overall survival and relapse-free survival for the entire group is 42% and 32%, respectively. Fifty patients were in complete remission 2 years post transplant. With additional follow-up, patients with high grade malignancies are cured, while patients with intermediate or low grade histologies were at continued risk of relapse up to 5 years post transplant. Of 39 patients in complete remission 5 years post transplant, none have relapsed with additional extended follow-up. We conclude that patients with NHL treated with ABMT, if in CR 5 years post transplant, are at very low risk of relapse with extended follow-up, suggesting the possibility of cure for all histologies, including those with low grade NHL.

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.

Intensification of salvage treatment with high-dose sequential chemotherapy improves the outcome of patients with refractory or relapsed aggressive non-Hodgkin's lymphoma

The aim of the present study was to retrospectively evaluate whether a high-dose sequential chemotherapy programme (HDS: cyclophosphamide, methotrexate, etoposide) administered prior to autologous transplantation could optimize the salvage of patients with refractory or relapsed aggressive non-Hodgkin's lymphoma. Between 1985 and 1999, 103 patients (median age 43 years, range 16-65) from eight Italian centres and one Swiss centre, with refractory (n = 38) or relapsed (n = 65) diffuse large B-cell and T-cell lymphoma, were treated using HDS followed by high-dose regimens with autologous haematopoietic stem cell transplantation. Eighty-three patients responded to the HDS regimen (81%, 95% C.I., 73- 88%) and 79 eventually achieved a complete response (CR) after autotransplantation (90%, 95% C.I., 81- 96%). None of 20 cases resistant to HDS attained CR. Treatment-related mortality was 4%. After a median follow-up of 24 months (range 6-174 months), 3-year estimates of overall survival, event-free survival and disease-free survival were 47% (95% C.I., 36-59%), 44% (95% C.I., 34-54%) and 64% (95% C.I., 50-74%) respectively. Multivariate analysis showed that chemosensitivity to HDS represented the strongest predictor of both CR and survival. This retrospective study shows that salvage treatment using HDS had relatively low toxicity and was associated with remarkable response rates, allowing further effective therapy with high-dose autograft programmes.

Bone Marrow TransplantationCurrent Clinical Practice: High-Dose Chemotherapy and Stem Cell Transplantation for Non-Hodgkin's Lymphoma: Review of Recent Advances

The past decade has seen impressive achievements in the development of HDT/SCT for NHL, but much remains to be accomplished. Attention can be focused now on high risk patients whose outcome with HDT/SCT, as currently practiced, is poor. This is particularly true for patients with refractory or resistant disease. The preliminary research work summarized in this review leads us to believe that further progress is forthcoming, to the benefit of the patient's survival and quality of life.