A prognostic model for prolonged event-free survival after autologous or allogeneic blood or marrow transplantation for relapsed and refractory Hodgkin's disease

Long-term outcomes for patients with Hodgkin lymphoma at increased risk of progression or relapse

Although advancements in the treatment of Hodgkin lymphoma have enabled many patients to be cured of their disease, about half of patients who relapse or experience refractory disease ultimately fail treatment, even after autologous stem cell transplant. Risk stratification is crucial to enable escalation of therapy in patients at increased risk for progression while allowing for less intensive therapy in lower risk groups. Utilization of clinical factors to inform risk scores was common practice, but this historical approach has been supplemented by PET/CT risk adapted management. Long-term outcomes of high-risk patients have improved over the decades with advancements in therapy and emergence of novel agents including antibody-drug conjugates and immune checkpoint inhibitors, yet further research is urgently needed. Herein, we review long-term outcomes of patients with Hodgkin lymphoma at increased risk for progression or relapse and discuss limitations of current risk strategies.

Reappraising the Role of Allogeneic Hematopoietic Stem Cell Transplantation in Relapsed and Refractory Hodgkin’s Lymphoma: Recent Advances and Outcomes

Hodgkin’s lymphoma is a rare yet highly curable disease in the majority of patients treated with modern chemotherapy regimens. For patients who fail to respond to or relapse after initial systemic therapies, treatment with high-dose chemotherapy and autologous hematopoietic stem cell transplantation can provide a cure for many with chemotherapy-responsive lymphoma. Patients who relapse after autologous transplant or those with chemorefractory disease have poor prognosis and represent a high unmet need. Allogeneic hematopoietic stem cell transplantation provides a proven curative therapy for these patients and should be considered, especially in young and medically fit patients. The use of newer agents in this disease such as brentuximab vedotin and immune checkpoint inhibitors can help bring more patients to transplantation and should be considered as well.

Disease Status at Transplant has a Significant Impact on Outcomes of Autologous Transplantation (ASCT) in Patients with Hodgkin Lymphoma—A Single Center Experience

High dose chemotherapy followed by autologous stem cell transplantation is the treatment of choice for relapsed Hodgkin lymphoma (HL). We analyzed 100 consecutive patients who underwent ASCT at our center between January 1999 and June 2019 for relapsed or refractory disease with a median age of 28 years (range: 9-65). At ASCT, 59 were in complete remission (CR) while 31 achieved partial remission (PR) and 10 had refractory disease (RD). Most had BEAM conditioning with a median infused cell dose of 4.84 × 10⁶ CD 34 cells/kg. Prompt engraftment occurred in 97 patients at a median of 11 days. The day 100 transplant related mortality (TRM) was 5%. At a median of 37 months follow up, 79 patients are alive while 34 have relapsed. The 3-year event free survival (EFS) and overall survival (OS) are 62.3 ± 0.5% and 77.9 ± 4.4% respectively. The 3-year OS for patients in CR, PR and RD were 83.0 ± 5.2%, 78.4 ± 8.1% and 38.9 ± 1.7 respectively [p = 0.007] while the 3-year EFS for CR, PR and RD were 73.1 ± 6.2%, 61.3 ± 9.2% and 25.0 ± 1.5 respectively [p = 0.005]. Only disease status at time of ASCT was found to correlate with both OS and EFS. ASCT for HL is associated with good outcomes and low TRM. Disease status at ASCT impacted both OS and EFS and strategies to improve outcomes in patients with refractory disease needs to be explored.

Relapse or refractory Hodgkin lymphoma: determining risk of relapse or progression after autologous stem-cell transplantation

The treatment of classic Hodgkin lymphoma (HL) is a success in onco-hematology. Despite the high cure rate of HL with initial therapy, 5-10% of patients are primary refractory and 10-20% will eventually relapse. The standard treatment for these patients is salvage chemotherapy and autologous stem cell transplantation (ASCT). Only about half of these patients will benefit from this procedure. The prognosis of relapsed refractory (rr) HL has improved with the introduction of effective drugs. With these options available, identification of reliable risk factors is important to guide treatment over the course of disease. Different variables including performance status, anemia, B symptoms, laboratory abnormalities, treatment intensity before ASCT, response to therapy, and duration of remission, have been analyzed to determine risk for progression-free survival (PFS) and overall survival (OS) after ASCT. This review will discuss the publications analyzing these factors, the validated risk scores useful to identify patients at high risk of progression after ASCT, and will describe future perspectives.

Outcome after autologous stem cell transplantation in primary refractory or relapsed Hodgkin lymphoma-a long-term follow-up single center experience

Autologous stem cell transplantation (autoSCT) can achieve long-term remission in primary refractory or relapsed Hodgkin lymphoma (r/r HL); however, still up to 50% of patients relapse after autoSCT. In this retrospective analysis, we investigated the impact of autologous stem cell transplantation in a consecutive, unselected cohort of primary refractory and relapsed Hodgkin lymphoma patients (n = 66) with the majority of patients treated in the pre-brentuximab vedotin and immune checkpoint inhibitor era. In our cohort, a 5-year overall survival (OS) from autoSCT of 59.5% and a 5-year progression-free survival (PFS) after autoSCT of 46.1% was achieved. Multivariate analysis revealed primary refractory disease and early relapse (< 12 months) after initial therapy as well as the presence of B symptoms at relapse as independent risk factors associated with a higher risk for relapse and an inferior PFS and OS. Several other clinical factors, including the presence of extranodal disease at relapse and failure to achieve a complete response to salvage chemotherapy, were associated with a trend towards an inferior survival. Patients relapsing after autoSCT had a particularly poor outcome, regardless of eligibility to undergo allogeneic stem cell transplantation (alloSCT). We further evaluated recently published prognostic models for r/r HL patients undergoing autoSCT and could validate several risk scores in our independent "real world" cohort.

Patterns of Failure and Survival Outcomes after Total Lymphoid Irradiation and High-Dose Chemotherapy with Autologous Stem Cell Transplantation for Relapsed or Refractory Classical Hodgkin Lymphoma

PURPOSE

The patterns of failure and long-term outcomes of patients with relapsed or refractory classical Hodgkin lymphoma treated with total lymphoid irradiation (TLI) and high-dose chemotherapy followed by autologous stem cell transplantation (aSCT) are reported.

METHODS AND MATERIALS

Patients with biopsy-proven primary refractory or relapsed classical Hodgkin lymphoma who received salvage chemotherapy and accelerated hyperfractionated TLI before high-dose chemotherapy and aSCT were included. Patterns of failure were delineated after fusing pretransplant planning computed tomography to the scan reporting the first failure. Survival rates were computed using the Kaplan-Meier method. Multivariate analysis using proportional hazards regression was done to determine prognostic factors for overall survival (OS) and progression-free survival (PFS).

RESULTS

Between 1993 and 2016, 89 patients underwent salvage treatments. Twenty patients failed at a median of 6.1 months after aSCT. Posttreatment scans were available for 16 patients who failed in a combined 43 different sites, 11 of which were extranodal. Patients failed at multiple sites, mostly within radiation fields. The 5-, 10-, and 15-year OS rates were 72.8%, 68.0%, and 58.3%; PFS rates were 73.3%, 68.5%, and 58.7%; event-free survival rates were 72.3%, 67.5%, and 57.8% respectively. The 5- and 10- year actuarial local control rates were both 77.6%. Complete response (CR) to salvage chemotherapy was associated with statistically significant improvements in OS and PFS. Eight patients developed secondary malignancies; 5 were hematologic and 3 were solid tumors.

CONCLUSIONS

Most failures were within the irradiated volume, which reflects the treatment-resistant disease biology. As part of a conditioning regimen, TLI yields good survival outcomes, particularly in patients achieving CR before transplant. However, need for RT in this setting should be assessed and new strategies should be developed to combat the treatment-resistant biology, especially in patients with less than CR after salvage chemotherapy.

Allogeneic hematopoietic stem cell transplantation in Hodgkin lymphoma: a systematic review and meta-analysis

Allogeneic stem cell transplantation (allo-SCT) outcomes in patients with Hodgkin lymphoma (HL) remain poorly defined. We performed a meta-analysis of allo-SCT studies in HL patients. The primary endpoints were 6-month, 1-year, 2-year and 3-year relapse-free survival (RFS) and overall survival (OS). A total of 42 reports (1850 patients) was included. The pooled estimates (95% confidence interval) for 6-month, 1-year, 2-year and 3-year RFS were 77 (59-91)%, 50 (42-57)%, 37 (31-43)% and 31 (25-37)%, respectively. The corresponding numbers for OS were 83 (75-91)%, 68 (62-74)%, 58 (52-64)% and 50 (41-58)%, respectively. There was statistical heterogeneity among studies in all outcomes. In meta-regression, accrual initiation year in 2000 or later was associated with higher 6-month (P=0.012) and 1-year OS (P=0.046), and pre-SCT remission with higher 2-year OS (P=0.047) and 1-year RFS (P=0.016). In conclusion, outcomes of allo-SCT in HL have improved over time, with 5-10% lower non-relapse mortality and relapse rates, and 15-20% higher RFS and OS in studies that initiated accrual in 2000 or later compared with earlier studies. However, there is no apparent survival plateau, demonstrating the need to improve on current allo-SCT strategies in relapsed/refractory HL.

A prognostic model predicting autologous transplantation outcomes in children, adolescents and young adults with Hodgkin lymphoma

Autologous hematopoietic cell transplantation (AutoHCT) is a potentially curative treatment modality for relapsed/refractory Hodgkin lymphoma (HL). However, no large studies have evaluated pre-transplant factors predictive of outcomes of AutoHCT in children, adolescents and young adults (CAYA, age <30 years). In a retrospective study, we analyzed 606 CAYA patients (median age 23 years) with relapsed/refractory HL who underwent AutoHCT between 1995–2010. The probabilities of progression free survival (PFS) at 1, 5 and 10 years were 66% (95% CI: 62–70), 52% (95% CI: 48–57) and 47% (95% CI: 42–51), respectively. Multivariate analysis for PFS demonstrated that at the time of AutoHCT patients with Karnofsky/Lansky score ≥90, no extranodal involvement and chemosensitive disease had significantly improved PFS. Patients with time from diagnosis to first relapse of <1 year had a significantly inferior PFS. A prognostic model for PFS was developed that stratified patients into low, intermediate and high-risk groups, predicting for 5-year PFS probabilities of 72% (95% CI: 64–80), 53% (95% CI: 47–59) and 23% (95% CI: 9–36), respectively. This large study identifies a group of CAYA patients with relapsed/refractory HL who are at high risk for progression after AutoHCT. Such patients should be targeted for novel therapeutic and/or maintenance approaches post-AutoHCT.

Simplified validated prognostic model for progression-free survival after autologous transplantation for hodgkin lymphoma

Hodgkin lymphoma (HL) prognostic models based on factors measured at time of autologous hematopoietic cell transplantation (AHCT) are limited by small sample sizes. Models based on information at diagnosis are often not uniformly collected or available at transplantation. We propose an easily implementable prognostic model for progression-free survival (PFS) post-AHCT based on factors available at transplantation in a large international cohort of HL patients. The outcomes of 728 AHCT recipients for relapsed/refractory HL were studied. Patients were randomly selected for model development (n = 337) and validation (n = 391). The multivariate model identified 4 major adverse risk factors at the time of AHCT with the following relative weights: Karnofsky performance score <90 and chemotherapy resistance at AHCT were each assigned 1 point, whereas at least 3 chemotherapy regimens pre-AHCT and extranodal disease at AHCT were each assigned 2 points. Based on the total score summed for the 4 adverse risk factors, 3 risk groups were identified: low (score = 0), intermediate (score = 1 to 3), or high (score = 4 to 6). The 4-year PFS for the low- (n = 176), intermediate- (n = 261), and high- (n = 283) risk groups were 71% (95% confidence interval [CI], 63% to 78%), 60% (95% CI, 53% to 66%), and 42% (95% CI, 36% to 49%), respectively. The prognostic model was validated in an independent cohort. The Center for International Blood and Marrow Transplant Research model is based on factors easily available at the time of AHCT and discriminates patients with favorable post-AHCT outcomes as well as an intermediate-risk group. This model should assist in the prospective evaluation of alternative treatment strategies.

Reporting methods in studies developing prognostic models in cancer: a review

BACKGROUND

Development of prognostic models enables identification of variables that are influential in predicting patient outcome and the use of these multiple risk factors in a systematic, reproducible way according to evidence based methods. The reliability of models depends on informed use of statistical methods, in combination with prior knowledge of disease. We reviewed published articles to assess reporting and methods used to develop new prognostic models in cancer.

METHODS

We developed a systematic search string and identified articles from PubMed. Forty-seven articles were included that satisfied the following inclusion criteria: published in 2005; aiming to predict patient outcome; presenting new prognostic models in cancer with outcome time to an event and including a combination of at least two separate variables; and analysing data using multivariable analysis suitable for time to event data.

RESULTS

In 47 studies, prospective cohort or randomised controlled trial data were used for model development in only 33% (15) of studies. In 30% (14) of the studies insufficient data were available, having fewer than 10 events per variable (EPV) used in model development. EPV could not be calculated in a further 40% (19) of the studies. The coding of candidate variables was only reported in 68% (32) of the studies. Although use of continuous variables was reported in all studies, only one article reported using recommended methods of retaining all these variables as continuous without categorisation. Statistical methods for selection of variables in the multivariate modelling were often flawed. A method that is not recommended, namely, using statistical significance in univariate analysis as a pre-screening test to select variables for inclusion in the multivariate model, was applied in 48% (21) of the studies.

CONCLUSIONS

We found that published prognostic models are often characterised by both use of inappropriate methods for development of multivariable models and poor reporting. In addition, models are limited by the lack of studies based on prospective data of sufficient sample size to avoid overfitting. The use of poor methods compromises the reliability of prognostic models developed to provide objective probability estimates to complement clinical intuition of the physician and guidelines.

Reporting performance of prognostic models in cancer: a review

BACKGROUND

Appropriate choice and use of prognostic models in clinical practice require the use of good methods for both model development, and for developing prognostic indices and risk groups from the models. In order to assess reliability and generalizability for use, models need to have been validated and measures of model performance reported. We reviewed published articles to assess the methods and reporting used to develop and evaluate performance of prognostic indices and risk groups from prognostic models.

METHODS

We developed a systematic search string and identified articles from PubMed. Forty-seven articles were included that satisfied the following inclusion criteria: published in 2005; aiming to predict patient outcome; presenting new prognostic models in cancer with outcome time to an event and including a combination of at least two separate variables; and analysing data using multivariable analysis suitable for time to event data.

RESULTS

In 47 studies, Cox models were used in 94% (44), but the coefficients or hazard ratios for the variables in the final model were reported in only 72% (34). The reproducibility of the derived model was assessed in only 11% (5) of the articles. A prognostic index was developed from the model in 81% (38) of the articles, but researchers derived the prognostic index from the final prognostic model in only 34% (13) of the studies; different coefficients or variables from those in the final model were used in 50% (19) of models and the methods used were unclear in 16% (6) of the articles. Methods used to derive prognostic groups were also poor, with researchers not reporting the methods used in 39% (14 of 36) of the studies and data derived methods likely to bias estimates of differences between risk groups being used in 28% (10) of the studies. Validation of their models was reported in only 34% (16) of the studies. In 15 studies validation used data from the same population and in five studies from a different population. Including reports of validation with external data from publications up to four years following model development, external validation was attempted for only 21% (10) of models. Insufficient information was provided on the performance of models in terms of discrimination and calibration.

CONCLUSIONS

Many published prognostic models have been developed using poor methods and many with poor reporting, both of which compromise the reliability and clinical relevance of models, prognostic indices and risk groups derived from them.

Prognostic significance of new immunohistochemical markers in refractory classical Hodgkin lymphoma: a study of 59 cases

Although most classical Hodgkin lymphoma patients are cured, a significant minority fail after primary therapy and may die as result of their disease. To date, there is no consensus on biological markers that add value to usual parameters (which comprise the International Prognostic Score) used at diagnosis to predict outcome. We evaluated 59 patients (18 with primary refractory or early relapse disease and 41 responders) for bcl2, Ki67, CD20, TiA1 and c-kit expression by semi-quantitative immunohistochemical study and correlated the results with the response to treatment.

The results showed that expression of bcl2 and CD20 in Hodgkin and Reed Sternberg cells, and expression of TiA1 in micro-environmental lymphocytes, and c-kit positive mast cells in microenvironment, were independent prognostic markers. These novel cHL markers could be used in association with clinical parameters to identify newly diagnosed patients with favorable or unfavorable prognosis and to better tailor treatment for different risk groups.

High-dose chemotherapy followed by autologous stem cell transplantation for relapsed or refractory Hodgkin lymphoma: Prognostic features and outcomes

Between January 1990 and April 2001, 115 patients received high-dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) for relapsed or refractory Hodgkin lymphoma (HL). With a median follow-up of 58 months (range, 1 - 175 months), 5-year progression-free survival (PFS) and overall survival (OS) were 46% and 58%, respectively. Twelve patients with primary refractory disease had a 5-year PFS of 41% and OS of 58%, not significantly different from those of the remaining cohort. Early and overall regimen related mortality were 7% and 16%, respectively. Male gender (P = 0.04) and a time to relapse (TTR) < 12 months (P = 0.03) were associated with decreased OS by univariate analysis. In multivariate analysis, TTR < 12 months remained statistically significant (P = 0.04). We have confirmed that HDT and ASCT result in long-term survival for a proportion of patients with relapsed or refractory HL. All patients, including those with primary refractory disease, benefited from HDT and ASCT.

Reduced intensity conditioning allogeneic stem cell transplantation for Hodgkin's lymphoma: identification of prognostic factors predicting outcome

BACKGROUND

The role of reduced intensity conditioning allogeneic stem transplantation (RICalloSCT) in the management of patients with Hodgkin's lymphoma remains controversial.

DESIGN AND METHODS

To further define its role we have conducted a retrospective analysis of 285 patients with HL who underwent a RICalloSCT in order to identify prognostic factors that predict outcome. Eighty percent of patients had undergone a prior autologous stem cell transplantation and 25% had refractory disease at transplant.

RESULTS

Non-relapse mortality was associated with chemorefractory disease, poor performance status, age >45 and transplantation before 2002. For patients with no risk factors the 3-year non-relapse mortality rate was 12.5% compared to 46.2% for patients with 2 or more risk factors. The use of an unrelated donor had no adverse effect on the non-relapse mortality. Acute graft versus host disease (aGVHD) grades II-IV developed in 30% and chronic GVHD in 42%. The development of cGVHD was associated with a lower relapse rate. The disease progression rate at one and five years was 41% and 58.7% respectively and was associated with chemorefractory disease and extent of prior therapy. Donor lymphocyte infusions were administered to 64 patients for active disease of whom 32% showed a clinical response. Eight out of 18 patients receiving donor lymphocyte infusions alone had clinical responses. Progression-free and overall survival were both associated with performance status and disease status at transplant. Patients with neither risk factor had a 3-year PFS and overall survival of 42% and 56% respectively compared to 8% and 25% for patients with one or more risk factors. Relapse within six months of a prior autologous transplant was associated with a higher relapse rate and a lower progression-free.

CONCLUSIONS

This analysis identifies important clinical parameters that may be useful in predicting the outcome of RICaIICalloSCT in Hodgkin's lymphoma.

The relationship between absolute lymphocyte count with PFS in patients with Hodgkin's lymphoma undergoing autologous hematopoietic cell transplant

Previous reports in Hodgkin's lymphoma (HL) patients undergoing autologous hematopoietic cell transplantation (AHCT) have demonstrated a significant association between the absolute lymphocyte count at day 15 (ALC-15) with survival. To evaluate this finding further, we analyzed 146 patients with relapsed/refractory HL who underwent AHCT to evaluate the relationship between lymphocyte counts at apheresis and at two time points (days 15 and 90) after AHCT with PFS. We found no association between the ALC-15 and the ALC-90 with PFS. We found lymphocyte counts at apheresis and disease sensitive to salvage chemotherapy were predictive of PFS. In conclusion, our study does provide some support for the theory that the immune system may be important in disease control but further and more detailed studies in this area are required.

Phase I/II trial of total lymphoid irradiation and high-dose chemotherapy with autologous stem-cell transplantation for relapsed and refractory Hodgkin's lymphoma

BACKGROUND

The standard approach to treatment of relapsed/refractory Hodgkin's lymphoma (HL) is high-dose chemotherapy conditioning followed by autologous hematopoietic stem-cell transplantation (aHSCT). We report the results of a prospective phase I/II clinical trial of accelerated hyperfractionated total lymphoid irradiation (TLI) immediately followed by high-dose chemotherapy for relapsed/refractory HL.

PATIENTS AND METHODS

Forty-eight patients underwent aHSCT with either sequential TLI/chemotherapy (n = 32) or chemotherapy-alone conditioning (n = 16), based on prior radiation exposure. The first 22 patients enrolled on trial received escalating doses of etoposide (1600-2100 mg/m(2)) with high-dose carboplatin and cyclophosphamide.

RESULTS

No dose-limiting toxicity was seen and TLI/chemotherapy was well tolerated. The 5-year event-free survival (EFS) estimate for all patients was 44% with overall survival (OS) of 48%. Five-year EFS and OS for the TLI/chemotherapy group was 63% and 61%, respectively, compared with 6% and 27%, respectively, for the chemotherapy-alone group (P < 0.0001 and P = 0.04, respectively). Patients with primary induction failure HL who received TLI/chemotherapy had 5-year EFS and OS rate of 83%. The 100-day treatment-related mortality was 4.2% and two secondary cancers were seen. Significant factors predicting survival by multivariate analysis included TLI/chemotherapy conditioning and B symptoms at relapse.

CONCLUSIONS

Sequential TLI/chemotherapy conditioning for relapsed/refractory HL is safe and associated with excellent long-term survival rates.

Early FDG-PET assessment in combination with clinical risk scores determines prognosis in recurring lymphoma

This study was set up to demonstrate whether prognostic classification based on the secondary age-adjusted International Prognostic Index (sAA-IPI) for recurring aggressive non-Hodgkin lymphoma (NHL) or the prognostic score for recurring Hodgkin lymphoma (HL) can be improved by including the midtreatment results of fluorine-18-fluorodeoxy-glucose-positron emission tomography (FDG-PET). Clinical data on patients with recurring lymphoma who were treated with second-line chemotherapy (DHAP-VIM-DHAP) followed by autologous stem cell transplantation (ASCT) were collected and combined with the results of FDG-PET performed before and after 2 cycles of reinduction chemotherapy. PET responses after 2 courses were scored as complete remission (CR), partial remission (PR), or no response (NR). A multivariate analysis was performed to design a predictive model. The number of patients (101 of 117) included those (78 patients with aggressive NHL and 23 patients with HL) that could be analyzed according to protocol. Of these, 80 patients were chemosensitive and 77 received transplants. Both secondary clinical risk score (P<.001) and FDG-PET response (P<.001) were independent predictive factors for the total evaluable group of patients with lymphoma and for patients with NHL alone. The combined use of the clinical risk score and FDG-PET response after 2 chemotherapy courses identified at least 4 categories of patients with a failure-free survival varying between 5% to 100% after transplantation (P<.001). These data indicate that the secondary clinical risk score in conjunction with FDG-PET response provides a more accurate prognostic instrument for the outcome of second-line treatment at least in patients with recurring NHL.