ABSTRACT
The scarcity of malignant Hodgkin and Reed-Sternberg cells hampers tissue-based comprehensive genomic profiling of classic Hodgkin lymphoma (cHL). By contrast, liquid biopsies show promise for molecular profiling of cHL due to relatively high circulating tumour DNA (ctDNA) levels1-4. Here we show that the plasma representation of mutations exceeds the bulk tumour representation in most cases, making cHL particularly amenable to noninvasive profiling. Leveraging single-cell transcriptional profiles of cHL tumours, we demonstrate Hodgkin and Reed-Sternberg ctDNA shedding to be shaped by DNASE1L3, whose increased tumour microenvironment-derived expression drives high ctDNA concentrations. Using this insight, we comprehensively profile 366 patients, revealing two distinct cHL genomic subtypes with characteristic clinical and prognostic correlates, as well as distinct transcriptional and immunological profiles. Furthermore, we identify a novel class of truncating IL4R mutations that are dependent on IL-13 signalling and therapeutically targetable with IL-4Rα-blocking antibodies. Finally, using PhasED-seq5, we demonstrate the clinical value of pretreatment and on-treatment ctDNA levels for longitudinally refining cHL risk prediction and for detection of radiographically occult minimal residual disease. Collectively, these results support the utility of noninvasive strategies for genotyping and dynamic monitoring of cHL, as well as capturing molecularly distinct subtypes with diagnostic, prognostic and therapeutic potential.
Subject(s)
Circulating Tumor DNA , Genome, Human , Genomics , Hodgkin Disease , Humans , Hodgkin Disease/blood , Hodgkin Disease/classification , Hodgkin Disease/diagnosis , Hodgkin Disease/genetics , Mutation , Reed-Sternberg Cells/metabolism , Tumor Microenvironment , Circulating Tumor DNA/blood , Circulating Tumor DNA/genetics , Single-Cell Gene Expression Analysis , Genome, Human/geneticsABSTRACT
Familial aggregation of Hodgkin lymphoma (HL) has been demonstrated in large population studies, pointing to genetic predisposition to this hematological malignancy. To understand the genetic variants associated with the development of HL, we performed whole genome sequencing on 234 individuals with and without HL from 36 pedigrees that had 2 or more first-degree relatives with HL. Our pedigree selection criteria also required at least 1 affected individual aged <21 years, with the median age at diagnosis of 21.98 years (3-55 years). Family-based segregation analysis was performed for the identification of coding and noncoding variants using linkage and filtering approaches. Using our tiered variant prioritization algorithm, we identified 44 HL-risk variants in 28 pedigrees, of which 33 are coding and 11 are noncoding. The top 4 recurrent risk variants are a coding variant in KDR (rs56302315), a 5' untranslated region variant in KLHDC8B (rs387906223), a noncoding variant in an intron of PAX5 (rs147081110), and another noncoding variant in an intron of GATA3 (rs3824666). A newly identified splice variant in KDR (c.3849-2A>C) was observed for 1 pedigree, and high-confidence stop-gain variants affecting IRF7 (p.W238∗) and EEF2KMT (p.K116∗) were also observed. Multiple truncating variants in POLR1E were found in 3 independent pedigrees as well. Whereas KDR and KLHDC8B have previously been reported, PAX5, GATA3, IRF7, EEF2KMT, and POLR1E represent novel observations. Although there may be environmental factors influencing lymphomagenesis, we observed segregation of candidate germline variants likely to predispose HL in most of the pedigrees studied.
Subject(s)
Hodgkin Disease , Humans , Young Adult , Adult , Hodgkin Disease/genetics , Genetic Predisposition to Disease , Germ-Line Mutation , Codon, Nonsense , Whole Genome Sequencing , Pedigree , Cell Cycle Proteins/geneticsABSTRACT
This systematic literature review evaluated frontline treatment burden in pediatric and adolescent/young adult (AYA) patients with high-risk classical Hodgkin lymphoma (cHL) among studies originating from the United States. Data were extracted from 32 publications (screened: total, n = 3115; full-text, n = 98) representing 12 studies (randomized controlled trials [RCTs], n = 2; non-comparative, non-randomized, n = 7; observational, n = 3). High-risk disease definitions varied across studies. Five-year event-free survival (EFS)/progression-free survival (PFS) was 86%-100% and 79%-94%, and complete response rates were 35%-100% and 5%-64% for brentuximab vedotin (BV)-containing and chemotherapy-alone regimens, respectively. In identified RCTs, BV-containing compared with chemotherapy-alone regimens demonstrated significantly longer 3-year EFS/5-year PFS. Hematological and peripheral neuropathy were the most commonly reported adverse events of interest, although safety data were inconsistently reported. Few studies evaluated humanistic and no studies evaluated economic burden. Results from studies with the highest quality of evidence indicate an EFS/PFS benefit for frontline BV-containing versus chemotherapy-alone regimens for pediatric/AYA patients with high-risk cHL.
Subject(s)
Hodgkin Disease , Adolescent , Child , Humans , Young Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Brentuximab Vedotin/therapeutic use , Hodgkin Disease/drug therapy , Hodgkin Disease/mortality , Hodgkin Disease/pathology , Hodgkin Disease/therapy , Prognosis , Survival RateABSTRACT
BACKGROUND: Disseminated pulmonary involvement in pediatric Hodgkin lymphoma (pHL) is indicative of Ann Arbor stage IV disease. During staging, it is necessary to assess for coexistence of non-malignant lung lesions due to infection representing background noise to avoid erroneously upstaging with therapy intensification. OBJECTIVE: This study attempts to describe new lung lesions detected on interim staging computed tomography (CT) scans after two cycles of vincristine, etoposide, prednisolone, doxorubicin in a prospective clinical trial. Based on the hypothesis that these new lung lesions are not part of the underlying malignancy but are epiphenomena, the aim is to analyze their size, number, and pattern to help distinguish true lung metastases from benign lung lesions on initial staging. MATERIALS AND METHODS: A retrospective analysis of the EuroNet-PHL-C1 trial re-evaluated the staging and interim lung CT scans of 1,300 pediatric patients with HL. Newly developed lung lesions during chemotherapy were classified according to the current Fleischner glossary of terms for thoracic imaging. Patients with new lung lesions found at early response assessment (ERA) were additionally assessed and compared to response seen in hilar and mediastinal lymph nodes. RESULTS: Of 1,300 patients at ERA, 119 (9.2%) had new pulmonary lesions not originally detectable at diagnosis. The phenomenon occurred regardless of initial lung involvement or whether a patient relapsed. In the latter group, new lung lesions on ERA regressed by the time of relapse staging. New lung lesions on ERA in patients without relapse were detected in 102 (7.8%) patients. Pulmonary nodules were recorded in 72 (5.5%) patients, the majority (97%) being<10 mm. Consolidations, ground-glass opacities, and parenchymal bands were less common. CONCLUSION: New nodules on interim staging are common, mostly measure less than 10 mm in diameter and usually require no further action because they are most likely non-malignant. Since it must be assumed that benign and malignant lung lesions coexist on initial staging, this benign background noise needs to be distinguished from lung metastases to avoid upstaging to stage IV disease. Raising the cut-off size for lung nodules to ≥ 10 mm might achieve the reduction of overtreatment but needs to be further evaluated with survival data. In contrast to the staging criteria of EuroNet-PHL-C1 and C2, our data suggest that the number of lesions present at initial staging may be less important.
Subject(s)
Hodgkin Disease , Lung Neoplasms , Neoplasm Staging , Tomography, X-Ray Computed , Humans , Male , Female , Hodgkin Disease/diagnostic imaging , Hodgkin Disease/pathology , Hodgkin Disease/drug therapy , Child , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Adolescent , Tomography, X-Ray Computed/methods , Retrospective Studies , Prevalence , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Prospective Studies , Child, Preschool , Doxorubicin/therapeutic use , Etoposide/therapeutic use , Etoposide/administration & dosage , Vincristine/therapeutic useABSTRACT
BACKGROUND: Hodgkin lymphoma (HL) is a treatable tumor affecting children, adolescents and young adults (AYAs; 15-39 years old). Population-based studies report worse survival for non-White children and AYAs but have limited data on individual therapeutic exposures. This study examined overall and HL-specific survival in a population-based cohort of patients while adjusting for sociodemographic factors and treatment. METHODS: Data for 4807 patients younger than 40 years with HL (2007-2017) were obtained from the California Cancer Registry. Individual treatment information was extracted from text fields; chemotherapy regimens were defined by standard approaches for pediatric and adult HL. Multivariable Cox models examined the influence of patient and treatment factors on survival. RESULTS: At a median follow-up of 4.4 years, 95% of the patients were alive. Chemotherapy differed by age, with 70% of 22- to 39-year-olds and 41% of <22-year-olds receiving doxorubicin, bleomycin, vinblastine, and dacarbazine (P < .001). In multivariable models, older patients (22-39 vs < 21 y; hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.11-2.10), Black (vs White patients); HR, 1.90; 95% CI, 1.25-2.88), and Hispanic patients (HR, 1.45; 95% CI, 1.06-1.99) experienced worse survival; among those < 21 y, Black race was associated with a 3.3-fold increased risk of death (HR, 3.26; 95% CI, 1.43-7.42). CONCLUSIONS: In children and AYAs with HL, older age and non-White race/ethnicity predicted worse survival after adjustments for treatment data. Further work is needed to identify the biological and nonbiological factors driving disparities in these at-risk populations.
Subject(s)
Hodgkin Disease , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Black People , Bleomycin , Child , Doxorubicin , Ethnicity , Hispanic or Latino , Hodgkin Disease/drug therapy , Humans , Vinblastine , Young AdultABSTRACT
The successful integration of clinical trials into pediatric oncology has led to steady improvement in the 5-year survival rate for children diagnosed with Hodgkin lymphoma (HL). It is estimated that >95% of children newly diagnosed with HL will become long-term survivors. Despite these successes, survival can come at a cost. Historically, long-term survivors of HL have a high risk of late-occurring adverse health effects and increased risk of nonrelapse mortality compared with the general population. The recognition of late-occurring events paired with the decades of life remaining for children cured of HL have made paramount the need to develop effective treatments that minimize the risk of late toxicity. Toward this goal, multiple, dose-intense, risk- and response-based regimens that use lower cumulative doses of chemotherapy and radiation have been developed. Appropriate frontline treatment selection requires a level of familiarity with the efficacy, acute toxicity, convenience, and late effects of treatments that may be impractical for providers who infrequently treat children with HL. There is an increasing need for guideline developers to begin to merge considerations from both frontline treatment and survivorship guidelines into practical documents that integrate potential long-term health risks. Herein, we take the first steps toward doing so by aligning cumulative treatment exposures, anticipated risks of late toxicity, and suggested surveillance recommendations for NCCN-endorsed Pediatric HL Guidelines. Future studies that integrate simulation modeling will strengthen this integrated approach and allow for opportunities to incorporate regimen-specific risks, health-related quality of life, and cost-effectiveness into decision tools to optimize HL therapy.
Subject(s)
Hodgkin Disease , Child , Disease Progression , Hodgkin Disease/diagnosis , Hodgkin Disease/therapy , Humans , Quality of Life , Survival Rate , SurvivorsABSTRACT
Hodgkin lymphoma (HL) is a highly curable form of cancer, and current treatment regimens are focused on improving treatment efficacy while decreasing the risk of late effects of treatment. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for pediatric HL provide recommendations on the workup, diagnostic evaluation, and treatment of classic HL, including principles of pathology, imaging, staging, systemic therapy, and radiation therapy. This portion of the NCCN Guidelines focuses on the management of pediatric classic HL in the upfront and relapsed/refractory settings.
Subject(s)
Hodgkin Disease , Child , Hodgkin Disease/diagnosis , Hodgkin Disease/pathology , Hodgkin Disease/therapy , Humans , Medical Oncology , Treatment OutcomeABSTRACT
Adolescents and young adults (AYAs) comprise the largest age group affected by Hodgkin lymphoma (HL). Despite excellent overall survival of AYA patients with HL due to advances in treatment regimens, therapy-associated late effects continue to be a concern in HL survivors, especially for younger patients who have decades of life remaining. Since the first clinical trial for HL with chemotherapy in 1964, subsequent protocols have attempted to reduce chemotherapy-induced toxicities and yet maintain high overall survival rates. Today, new analytic methods applied to data from survivorship cohorts, such as the recently described cumulative burden of disease metric, can be used to inform changes for future protocols. Although pediatric and adult trial consortia have followed this process, the AYA population, an age cohort split between pediatric and adult health care services, faces many barriers to care and is the least likely to be enrolled in clinical trials. AYA patients with HL theoretically have a choice to be treated in pediatric or adult protocols when presented with these options. Recent efforts by the National Clinical Trials Network, the Children's Oncology Group, and others have been made to ensure that the burden of choice for the AYA population is not greater than the burden of disease.
Subject(s)
Decision Making , Delivery of Health Care , Hodgkin Disease/therapy , Practice Guidelines as Topic/standards , Adolescent , Adult , Choice Behavior , Disease Management , Hodgkin Disease/pathology , Humans , Risk Factors , Young AdultABSTRACT
BACKGROUND: The International Working Group on Staging Evaluation and Response Criteria Harmonization (SEARCH) seeks to provide a universally acceptable definition of cortical bone involvement in the staging of newly diagnosed pediatric Hodgkin lymphoma. PROCEDURE: A comprehensive literature search was performed using PubMed and Google Scholar with the search terms "Hodgkin lymphoma," "osseous lesions," "bony involvement," and "pediatric." Publications reviewed included case reports, retrospective analyses, and literature reviews. Each was evaluated for study design, number of participants, median age and age range at diagnosis, percentage of pediatric patients, criteria of interest definition, diagnostic tools, study objectives, and level of evidence. The final definition was based on the available data and consensus of the SEARCH working group. RESULTS: Twenty-five papers specifically addressing cortical bone involvement in Hodgkin lymphoma met the inclusion criteria. Eighteen papers were case reports with literature reviews; the remainder were observational cohort studies. Of these, 14 included pediatric patients (aged 0-21 years). The criteria for cortical bone involvement were not clearly defined in any paper, often varied within a study, and were inconsistent between publications. CONCLUSIONS: The SEARCH group for Childhood, Adolescent, and Young Adult Hodgkin Lymphoma (CAYAHL) proposes the following criteria as defining cortical bone involvement: any cortical bone biopsy-proven lesion; a positive bony window lesion on computer tomography (CT), with an FDG-PET positive correlate in a patient with biopsy-proven Hodgkin lymphoma, if there is no other typical skeletal pathology; auspicious skeletal lesions on FDG-PET or magnetic resonance imaging should be confirmed by CT or Tc-99m scan to distinguish cortical lesions from bone marrow involvement. Nodal masses that extend into bone with bony destruction are considered extranodal extension or "E" lesions and do not represent metastatic or stage IV disease.
Subject(s)
Cortical Bone/pathology , Diagnostic Imaging/methods , Hodgkin Disease/classification , Hodgkin Disease/pathology , Child , Cortical Bone/diagnostic imaging , Hodgkin Disease/diagnostic imaging , Humans , Neoplasm Staging , Response Evaluation Criteria in Solid TumorsABSTRACT
Hepatic involvement in Hodgkin lymphoma (HL) is uncommon (â¼5% of patients) but always implies stage IV disease. Accurate staging is mandatory for making the appropriate risk assignment and treatment decisions. The Staging Evaluation and Response Criteria Harmonization for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) international working group conducted a systematic literature review of liver involvement in HL patients with the aim to propose a universally acceptable definition for liver involvement in pediatric HL. Thirty-three articles describing 6985 pediatric and adult HL patients were reviewed, of which 539 (7.7%) mentioned liver involvement. The literature did not provide a uniform definition of hepatic involvement and we propose consensus criteria derived from the EuroNet and Children's Oncology Group protocols, where liver involvement is defined as any hepatic lesion on computed tomography scan that correlates with 18 F-FDG uptake greater than background liver. A clear definition of liver lesions is necessary to consistently identify liver involvement and compare its impact on outcomes among protocols worldwide.
Subject(s)
Fluorodeoxyglucose F18/therapeutic use , Hodgkin Disease/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Liver/diagnostic imaging , Positron-Emission Tomography , Adolescent , Adult , Child , Child, Preschool , Female , Hodgkin Disease/pathology , Hodgkin Disease/therapy , Humans , Infant , Liver/pathology , Liver Neoplasms/pathology , Liver Neoplasms/therapy , Male , Neoplasm Staging , Young AdultABSTRACT
Waldeyer's ring (WR) involvement in pediatric Hodgkin lymphoma (HL) is extremely rare and criteria for determining involvement and response to treatment are unclear. The international Staging, Evaluation, and Response Criteria Harmonization for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) Group performed a systematic review of the literature in search of involvement or response criteria, or evidence to support specific criteria. Only 166 cases of HL with WR involvement were reported in the literature, 7 of which were pediatric. To date no standardized diagnostic or response assessment criteria are available. Given the paucity of evidence, using a modified Delphi survey technique, expert consensus statements were developed by the SEARCH group to allow for a more consistent definition of disease and response evaluation related to this rare site of involvement among pediatric oncologists. The available evidence and expert consensus statements are summarized.
Subject(s)
Hodgkin Disease/pathology , Oropharynx/diagnostic imaging , Oropharynx/pathology , Adenoids/pathology , Expert Testimony , Fluorodeoxyglucose F18 , Hodgkin Disease/diagnostic imaging , Humans , Palate, Soft/pathology , Palatine Tonsil/pathology , Positron-Emission Tomography , Tongue/pathologyABSTRACT
International harmonization of staging evaluation and response criteria is needed for childhood, adolescence, and young adulthood Hodgkin lymphoma. Two Hodgkin lymphoma protocols from cooperative trials in Europe and North America were compared for areas in need of harmonization, and an evidence-based approach is currently underway to harmonize staging and response evaluations with a goal to enhance comparisons, expedite identification of effective therapies, and aid in the approval process for new agents by regulatory agencies.
Subject(s)
Hodgkin Disease/pathology , Neoplasm Staging/methods , Neoplasm Staging/standards , Adolescent , Child , Female , Humans , Male , Young AdultSubject(s)
Antineoplastic Agents, Immunological/therapeutic use , Brentuximab Vedotin/therapeutic use , Hodgkin Disease/drug therapy , Salvage Therapy , Adolescent , Adult , Consolidation Chemotherapy , Female , Follow-Up Studies , Hematopoietic Stem Cell Transplantation/methods , Hodgkin Disease/therapy , Humans , Male , Remission Induction , Retrospective Studies , Treatment Outcome , Young AdultABSTRACT
Hodgkin lymphoma (HL) involving the central nervous system (CNS) is exceedingly rare. Information regarding the presentation, management, treatment and outcome of patients with CNS HL is limited to case reports or small series. We describe 45 pediatric patients with 55 extra-axial CNS lesions at diagnosis with HL from a cohort of 4995 patients enrolled on Children's Oncology Group AHOD1331 and the European Network for Pediatric Hodgkin lymphoma (EuroNet-PHL) C1 and C2 trials (NCT02166463, NCT00433459 and NCT02684708, clinicaltrials.gov), with an overall incidence of 0.9%. 82.2% of patients had a single CNS lesion in the thoracic, lumbar or sacral spine. In the evaluated cohort, HL did not occur within the CNS parenchyma. Lesions extended into the extra-axial CNS space from adjacent soft tissue or bone and never directly infiltrated through the dura into the brain or spinal cord. Patients with CNS involvement had a 2-fold greater incidence of extranodal lesions (E-lesions) than previously reported cohorts without CNS involvement. 89.1% of CNS lesions demonstrated a complete metabolic response and >75% decrease in volume after two cycles of chemotherapy. Thirteen CNS lesions (23.6%) received irradiation, none were sites of disease relapse. Relapse occurred at the site of two lesions involving the CNS, both of which had an adequate interim response to chemotherapy. In summary, we present the largest reported cohort of systemic HL involving the CNS at diagnosis, demonstrating that these lesions originate from surrounding tissues, extend into the extra-axial CNS space, and respond similarly to other nodal and extranodal disease.
ABSTRACT
Data commons have proven to be an indispensable avenue for advancing pediatric cancer research by serving as unified information technology platforms that, when coupled with data standards, facilitate data sharing. The Pediatric Cancer Data Commons, the flagship project of Data for the Common Good (D4CG), collaborates with disease-based consortia to facilitate development of clinical data standards, harmonization and pooling of clinical data from disparate sources, establishment of governance structure, and sharing of clinical data. In the interest of international collaboration, researchers developed the Hodgkin Lymphoma Data Collaboration and forged a relationship with the Pediatric Cancer Data Commons to establish a data commons for pediatric Hodgkin lymphoma. Herein, we describe the progress made in the formation of Hodgkin Lymphoma Data Collaboration and foundational goals to advance pediatric Hodgkin lymphoma research.
Subject(s)
Hodgkin Disease , Hodgkin Disease/therapy , Humans , Child , Information Dissemination , Biomedical Research/organization & administration , Databases, FactualABSTRACT
PURPOSE: Hodgkin lymphoma (HL) survivors experience neurocognitive impairment despite receiving no central nervous system-directed therapy, though little is known about the underlying mechanisms. EXPERIMENTAL DESIGN: HL survivors (n = 197) and age-, sex- and race/ethnicity frequency-matched community controls (n = 199) underwent standardized neurocognitive testing, and serum collection. Luminex multiplex or ELISA assays measured markers of inflammation and oxidative stress. Linear regression models compared biomarker concentrations between survivors and controls and with neurocognitive outcomes, adjusting for age, sex, race, body mass index, anti-inflammatory medication, and recent infections. RESULTS: HL survivors [mean (SD) current age 36 (8) years, 22 (8) years after diagnosis] demonstrated higher concentrations of interleukin-6 (IL6), high-sensitivity c-reactive protein (hs-CRP), oxidized low-density lipoprotein, and glutathione peroxidase (GPx), compared with controls (P's < 0.001). Among survivors, higher concentrations of IL6 were associated with worse visuomotor processing speed (P = 0.046). hs-CRP ≥3 mg/L was associated with worse attention, processing speed, memory, and executive function (P's < 0.05). Higher concentrations of malondialdehyde were associated with worse focused attention and visual processing speed (P's < 0.05). Homocysteine was associated with worse short-term recall (P = 0.008). None of these associations were statistically significant among controls. Among survivors, hs-CRP partially mediated associations between cardiovascular or endocrine conditions and visual processing speed, whereas IL6 partially mediated associations between pulmonary conditions and visuomotor processing speed. CONCLUSIONS: Neurocognitive function in long-term survivors of HL appears to be associated with inflammation and oxidative stress, both representing potential targets for future intervention trials.
Subject(s)
Biomarkers , Cancer Survivors , Hodgkin Disease , Oxidative Stress , Humans , Female , Male , Adult , Cancer Survivors/psychology , Cancer Survivors/statistics & numerical data , Neurocognitive Disorders/etiology , Neurocognitive Disorders/epidemiology , C-Reactive Protein/metabolism , Neuropsychological Tests , Interleukin-6/blood , Inflammation , Middle Aged , Case-Control Studies , Child , Survivors/psychology , AdolescentABSTRACT
Hypodense volumes (HDV) in mediastinal masses can be visualized in a computed tomography scan in Hodgkin lymphoma. We analyzed staging CT scans of 1178 patients with mediastinal involvement from the EuroNet-PHL-C1 trial and explored correlations of HDV with patient characteristics, mediastinal tumor volume and progression-free survival. HDV occurred in 350 of 1178 patients (29.7%), typically in larger mediastinal volumes. There were different patterns in appearance with single lesions found in 243 patients (69.4%), multiple lesions in 107 patients (30.6%). Well delineated lesions were found in 248 cases (70.1%), diffuse lesions were seen in 102 cases (29.1%). Clinically, B symptoms occurred more often in patients with HDV (47.7% compared to 35.0% without HDV (p = 0.039)) and patients with HDV tended to be in higher risk groups. Inadequate overall early-18F-FDG-PET-response was strongly correlated with the occurrence of hypodense lesions (p < 0.001). Patients with total HDV > 40 ml (n = 80) had a 5 year PFS of 79.6% compared to 89.7% (p = 0.01) in patients with HDV < 40 ml or no HDV. This difference in PFS is not caused by treatment group alone. HDV is a common phenomenon in HL with mediastinal involvement.