Response-adapted omission of radiotherapy in children and adolescents with early-stage classical Hodgkin lymphoma and an adequate response to vincristine, etoposide, prednisone, and doxorubicin (EuroNet-PHL-C1): a titration study

Meeting proceedings: International Society for Fertility Preservation Tokyo, 15-17 November, 2024

The 8 th International Congress of the ISFP was held in Tokyo, Japan, from November 15 to 17, 2024. The theme of this year's Congress was "Rethinking Personalized Fertility Preservation and Cancer Survivors-Opening a New Frontier". The congress featured special lectures, keynote addresses, and 25 sessions-including a dedicated session on nursing and oral presentations by young doctors and researchers-making it one of the largest and most comprehensive events in the ISFP's history. Additionally, the program incorporated sessions featuring the Japanese, Korean, and Chinese Societies for Fertility Preservation, providing a convenient platform for international participants from across the globe to showcase their work and discuss the unique characteristics and challenges of these areas within Asia. Participants also had the opportunity to attend workshops on ovarian tissue cryopreservation and oocyte cryopreservation, conducted by leaders in their respective fields exploring the latest technological and clinical advances and translational prospects for the future.

Prognostic Impact of Quantitative Changes Between Baseline and Interim 18F-FDG PET/CT in Pediatric Classic Hodgkin Lymphoma

PURPOSE

18F-FDG PET/CT plays a crucial role in the evaluation and management of pediatric classic Hodgkin lymphoma (cHL). In addition to visual assessment, quantitative parameters also have prognostic value. This study aimed to investigate the prognostic significance of PET parameters, with a particular focus on the changes observed in these parameters after 2 cycles of chemotherapy, in pediatric cHL patients.

PATIENTS AND METHODS

The study was designed as a single-center, retrospective. A total of 198 pediatric cHL patients who underwent baseline and post-2-cycle chemotherapy interim 18F-FDG PET/CT imaging between January 2019 and October 2023 were included in the study. Four different segmentation methods (%41 SUVmax, %42 SUVmax, mediastinal SUVmax, and liver SUVmax) were applied. Quantitative parameters, including metabolic tumor volume (MTV), total lesion glycolysis (TLG), and their changes after 2 chemotherapy cycles (ΔMTV, ΔTLG), were evaluated for each segmentation method. The prognostic significance of these parameters for progression-free survival (PFS) was assessed using Cox regression analysis, while survival differences based on optimal cutoff values were evaluated using Kaplan-Meier analysis.

RESULTS

A total of 48 pediatric cHL patients (32 males, median age: 12 y) met the inclusion criteria. During a median follow-up of 21 months (range: 5-52 mo), disease progression was observed in 22.9% of the patients (n=11). Baseline 18F-FDG PET/CT quantitative parameters did not show significant differences between progression and nonprogression groups. However, on interim 18F-FDG PET/CT, higher values of quantitative parameters from 3 segmentation methods (%41 SUVmax, %42 SUVmax, and mediastinal SUVmax) and lower postchemotherapy reductions in ΔSUVmax, ΔMTV(41), ΔMTV(42), ΔTLG(41), and ΔTLG(med) were associated with poor PFS. In multivariate Cox regression analysis, i-SUVmax (Hazard ratio, HR: 1.20, P<0.001) and ΔMTV(41) (HR: 0.965, P=0.007) were identified as independent risk factors for PFS.

CONCLUSIONS

Interim 18F-FDG PET parameters and postchemotherapy changes demonstrated significant prognostic value. Quantitative evaluation beyond visual assessment may contribute to risk-adapted and personalized treatment approaches in pediatric cHL.

Transplant and Nontransplant Salvage Therapy in Pediatric Relapsed or Refractory Hodgkin Lymphoma: The EuroNet-PHL-R1 Phase 3 Nonrandomized Clinical Trial

Importance

The current standard-of-care salvage therapy in relapsed/refractory classic Hodgkin lymphoma (cHL) includes consolidation high-dose chemotherapy (HDCT)/autologous stem cell transplant (aSCT).

Objective

To investigate whether presalvage risk factors and fludeoxyglucose-18 (FDG) positron emission tomography (PET) response to reinduction chemotherapy can guide escalation or de-escalation between HDCT/aSCT or transplant-free consolidation with radiotherapy to minimize toxic effects while maintaining high cure rates.

Design, Setting, and Participants

EuroNet-PHL-R1 was a nonrandomized clinical trial that enrolled patients younger than 18 years with first relapsed/refractory cHL across 68 sites in 13 countries in Europe between January 2007 and January 2013. Data were analyzed between September 2022 and July 2024.

Intervention

Reinduction chemotherapy consisted of alternating IEP (ifosfamide, etoposide, prednisolone) and ABVD (adriamycin, bleomycin, vinblastine, dacarbazine). Patients with low-risk disease (late relapse after 2 cycles of first-line chemotherapy and any relapse with an adequate response after 1 IEP/ABVD defined as complete metabolic response on FDG-PET and at least 50% volume reduction) received a second IEP/ABVD cycle and radiotherapy (RT) to all sites involved at relapse. Patients with high-risk disease (all primary progressions and relapses with inadequate response after 1 IEP/ABVD cycle) received a second IEP/ABVD cycle plus HDCT/aSCT with or without RT.

Main Outcomes and Measures

The primary end point was 5-year event-free survival. Secondary end points were overall survival (OS) and progression-free survival (PFS). PFS was identical to event-free survival because no secondary cancers were observed. PFS data alone are presented for simplicity.

Results

Of 118 patients analyzed, 58 (49.2%) were female, and the median (IQR) age was 16.3 (14.5-17.6) years. The median (IQR) follow-up was 67.5 (58.5-77.0) months. The overall 5-year PFS was 71.3% (95% CI, 63.5%-80.1%), and OS was 82.7% (95% CI, 75.8%-90.1%). For patients in the low-risk group (n = 59), 41 received nontransplant salvage with a 5-year PFS of 89.7% (95% CI, 80.7%-99.8%) and OS of 97.4% (95% CI, 92.6%-100%). In contrast, 18 received HDCT/aSCT off protocol, with a 5-year PFS of 88.9% (95% CI, 75.5%-100%) and OS of 100%. All 59 patients with high-risk disease received HDCT/aSCT (and 23 received post-HDCT/aSCT RT) with a 5-year PFS of 53.3% (95% CI, 41.8%-67.9%) and OS of 66.5% (95% CI, 54.9%-80.5%).

Conclusion and Relevance

In this nonrandomized clinical trial, FDG-PET response-guided salvage in relapsed cHL may identify patients in whom transplant-free salvage achieves excellent outcomes. HDCT/aSCT may be reserved for primary progression and relapsed cHL with inadequate response.

Trial Registration

ClinicalTrials.gov Identifier: NCT00433459.

IFN-γ reprograms cardiac microvascular endothelial cells to mediate doxorubicin transport and influences the sensitivity of mice to doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a first-line chemotherapy agent known for its cardiac toxicity. DOX-induced cardiotoxicity (DIC) severely limits the use for treating malignant tumors and is associated with a poor prognosis. The sensitivity to DIC varies among patients, but the precise mechanisms remain elusive. Here we constructed a mouse model of DIC using DOX to investigate potential mechanisms contributing to the differential susceptibility to DIC. Through surface-enhanced Raman spectroscopy and single-cell RNA sequencing, we explored the mechanisms underlying DIC phenotypic variations. In vitro and in vivo studies with small-molecule drugs were conducted. DIC-insensitive mice displayed preserved ejection fractions, lower DOX levels in cardiac tissues and higher levels in the serum. Single-cell RNA sequencing revealed differences of gene expression in cardiac endothelial cells between DIC-insensitive and DIC-sensitive groups. The expression of IFN-γ pathway-related genes was high in DIC-insensitive mice. IFN-γ administration decreased the DOX distribution in cardiac tissues, whereas PPAR-γ activation increased DIC susceptibility. IFN-γ stimulation upregulated P-glycoprotein expression, leading to increased DOX efflux and DIC insensitivity. Our model provides insights into the mechanisms of DIC sensitivity and potential preventive strategies.

CT, MRI, and FDG PET/CT in the Assessment of Lymph Node Involvement in Pediatric Hodgkin Lymphoma: An Expert Consensus Definition by an International Collaboration on Staging Evaluation and Response Criteria Harmonization for Children, Adolescent, and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL)

Staging of pediatric Hodgkin lymphoma is currently based on the Ann Arbor classification, incorporating the Cotswold modifications and the Lugano classification. The Cotswold modifications provide guidelines for the use of CT and MRI. The Lugano classification emphasizes the importance of CT and PET/CT in evaluating both Hodgkin lymphoma and non-Hodgkin lymphoma but focuses on adult patients. This article presents consensus guidelines that extend the traditional classifications used for adult Hodgkin lymphoma staging and provide rigorous definitions of lymph node groups based on MRI, CT, and fluorodeoxyglucose PET/CT findings. This allows consistent terminology and definitions, using metabolic and morphologic imaging to identify affected lymph nodes or extranodal regions and organs. The pattern of involvement, together with other individual risk factors, determines treatment strategy. In case of inadequate response to chemotherapy, radiation therapy is often required. Standardization of staging definitions for pediatric Hodgkin lymphoma is necessary for comparing treatment outcomes between North American and European clinical trials and a prerequisite for clear communication during tumor boards and central review. This comprehensive imaging atlas is intended to provide regional criteria for nodal involvement and to serve as a standardized guide for the anatomic assignment of lymph node involvement in pediatric Hodgkin lymphoma.

The Role of Radiotherapy in Hematologic Malignancies in Children, Adolescents, and Young Adults

Hematologic cancers in pediatric, adolescent, and young adult populations include a diverse spectrum of malignancies. The cornerstone of treatment is multiagent chemotherapy. While radiation therapy (RT) is highly effective and played a pivotal role historically, its use has evolved. In classic HL, advancements in systemic therapy have allowed for reduced RT volumes and doses and careful patient selection. Similarly, NLPHL management has shifted toward observation after complete resection, or limited chemotherapy after incomplete resection with RT used only for partially responding disease sites. In primary mediastinal B-cell lymphoma, the role of RT is an area of active study, and treatment with chemotherapy alone has shown promise in adults. Frontline treatment of diffuse large B-cell lymphoma and Burkitt lymphoma relies on chemotherapy; evidence do not support a role for consolidative RT. In leukemia, the use of prophylactic cranial and testicular RT is declining in the setting of modern chemotherapy regimens. RT may play an important role in the salvage of relapsed/refractory lymphomas and leukemias. In addition, palliative RT is often integral to symptom relief and function preservation. Future research aims to refine risk stratification, personalize treatment approaches, and incorporate novel therapies to maintain or improve oncologic outcomes while mitigating late effects.

Risk-Stratified Radiotherapy in Pediatric Cancer

While the cure rate of cancer in children has markedly improved in the last few decades, late effects continue to be a problem in survivors. Radiotherapy, which is a major component of treatment in many cancers, is one of the major agents responsible for late toxicity. In the past decade, radiotherapy has been omitted in patients achieving excellent response to chemotherapy, such as in Hodgkin lymphoma and some Wilms tumors with lung metastases. Likewise, response to chemotherapy has been used to determine whether lower doses of radiation can be delivered in intracranial germinoma and pediatric nasopharyngeal carcinoma. Molecular subtyping in medulloblastoma is currently being employed, and in WNT-pathway M0 tumors, the reduction in radiotherapy dose to the craniospinal axis and tumor bed is currently being investigated. Finally, dose escalation was recently evaluated in patients with rhabdomyosarcoma > 5 cm who do not achieve a complete response to initial 9 weeks of chemotherapy as well as for unresectable Ewing sarcoma patients to improve local control.

Hodgkin lymphoma involving the extra-axial CNS: an AHOD1331, PHL-C1, and PHL-C2 report from the COG and EuroNet-PHL

ABSTRACT

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 C1 and C2 trials, with an overall incidence of 0.9%. Up to 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 twofold greater incidence of extranodal lesions than previously reported cohorts without CNS involvement. After 2 cycles of chemotherapy, 89.1% of CNS lesions demonstrated a complete metabolic response and >75% decrease in volume. Thirteen CNS lesions (23.6%) received irradiation; none were sites of disease relapse. Relapse occurred at the site of 2 lesions involving the CNS, both of which had an adequate interim response to chemotherapy. In summary, we present, to our knowledge, 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. The trials were registered at www.clinicaltrials.gov as #NCT02166463, #NCT00433459, and #NCT02684708.

Successful treatment of paediatric refractory Hodgkin lymphoma with immunotherapy - A case report and literature review

AIM

To describe a rare case of primary refractory Hodgkin lymphoma nodular sclerosis syncytial variant in a child and review immunotherapy in relapsed/refractory Hodgkin lymphoma.

METHODS

We described the treatment course of a child with primary refractory classic Hodgkin lymphoma and discussed different options for salvage therapy, with an emphasis on immunotherapy. We searched PubMed for all published clinical trials investigating immunotherapy in classic Hodgkin lymphoma written in English until 31 June, 2023. The reference list of each identified paper was searched for additional publications.

RESULTS

Our patient was salvaged with anti-programmed cell death 1 (PD-1) antibody therapy followed by high-dose chemotherapy with autologous stem cell rescue. Radiotherapy was avoided. We identified five one-armed phase II trials investigating anti-PD-1 therapy in first relapse/refractory disease in a total of 254 patients aged 9-71 years, of which one included 31 children. The complete remission rate before high-dose chemotherapy was 59%-95% overall and 67%-89% among those with refractory disease.

CONCLUSION

Although it remains to be proven in randomised trials, anti-PD-1 therapy may provide higher complete response rates than traditional chemotherapy. Anti-PD-1 therapy has the potential to increase the chance of cure while decreasing the risk of late effects from chemotherapy and radiotherapy.

Hodgkin lymphoma: hypodense lesions in mediastinal masses

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.

Pediatric and Adolescent Hodgkin Lymphoma: Paving the Way for Standards of Care and Shared Decision Making

Hodgkin lymphoma (HL) is a treatable cancer with an incidence peak in adolescent and young adult years. Treatment strategies have been developed to balance the intensity of therapy needed to maintain disease-free survival while simultaneously preserving overall survival. Risk-based, response-adapted frontline therapy has long used a combination of chemotherapy and radiotherapy (RT). Successive clinical trials over the past three decades have safely reduced cumulative alkylator, anthracycline, and RT exposures for many patients. The advent of checkpoint inhibitors and the CD30-targeted antibody drug conjugate, brentuximab vedotin, has provided new options for de-escalation of conventional therapies associated with late effects in survivors treated at a young age. The ability to evaluate novel agents has been accelerated in collaborative trials inclusive of children and adolescents within the US National Clinical Trials Network and between the Children's Oncology Group and the EuroNet Pediatric Hodgkin Lymphoma Consortium. With numerous treatment options, patients with HL and their clinicians have an opportunity for shared decision making from diagnosis, through cancer treatment, and into survivorship. Given excellent survival outcomes, decisions about treatment in classic HL should be collaborative and attention to long-term survivorship needs should remain a high priority. Patient-reported outcomes remain an important tool to aid clinicians working with survivors to optimize health status and related quality of life for decades after HL therapy.

The pediatric approach to Hodgkin lymphoma

Hodgkin lymphoma (HL) occurs throughout the lifespan but is one of the most common cancers in adolescents and young adults (AYA; 15-39 years). HL has become a highly curable disease with survival rates surpassing 90%, including patients with high-risk and advanced stage disease. Unfortunately, intensive treatment carries a risk of short- and long-term toxicity. Given the decades pediatric HL survivors are expected to live after treatment, the pediatric approach to treatment has focused on improving the therapeutic index through response adapted treatment and more recently the incorporation of novel agents. The efforts of pediatric and medical oncologists in research and clinical trial development have long occurred in parallel, but recent efforts have laid the foundation for collaboration with the goal of standardizing AYA care and allowing earlier incorporation of novel therapy for younger patients. This review focuses on the evolution of the management of pediatric HL including epidemiology, biology, and approaches to upfront and salvage treatment regimens.

Pulmonary lesions in early response assessment in pediatric Hodgkin lymphoma: prevalence and possible implications for initial staging

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.

Update on FDG-PET in pediatric lymphoma

Lymphoma represent the third most common malignant disease in childhood and adolescence. They are divided into pediatric Hodgkin lymphoma (P-HL) and pediatric non-Hodgkin lymphoma (P-NHL). In P-HL, excellent cure rates are achieved through combined modality treatment using chemotherapy and radiotherapy. For more than 20 years, FDG-PET has been an integral part of the treatment and guides its intensity through improved staging and precise assessment of chemotherapy response. In P-NHL, good cure rates are achieved with chemotherapy alone. At present FDG-PET plays only a subordinate role in the treatment setting. Its potential to contribute to treatment management is far from being fully utilised. In this article, the current status of FDG-PET in pediatric lymphoma is presented in detail. The core elements are the sections on staging and response assessment. In addition, challenges and pitfalls are discussed and future developments are outlined.

Classic Hodgkin Lymphoma in Adolescents and Young Adults

Hodgkin lymphoma (HL) represents one of the more common cancers occurring in adolescent and young adults (AYAs) age 15-39 years. Despite a generally high cure rate, age-related differences in HL biology and the optimal therapeutic approaches including supportive care and risks for long-term adverse effects in the AYA population remain understudied. After an overview of HL epidemiology and biology in the AYA population, this review will cover frontline pediatric and adult treatment approaches. Recently completed and ongoing studies will foster harmonization of risk group definition and trial eligibility criteria across the AYA spectrum, enabling more rapid progress. In addition to treatment approaches, an evolving holistic care approach to AYA HL will result in enhanced understanding of unique challenges, and continued improved short- and long-term outcome for these patients.

Prevention of activated brown adipose tissue on 18F-FDG-PET scans of young lymphoma patients: results of an ancillary study within the EuroNet-PHL-C2 trial

Activated brown fat (aBAT) is known to affect the evaluation of 18F-FDG PET scans, especially in young patients. The aim of this study was to determine factors influencing the occurrence of aBAT, and to investigate the effectiveness of the two preventive measures, warming and beta-blocker (propranolol) administration. Five-hundred-twenty-eight 18F-FDG-PET scans of 241 EuroNet-PHL-C2 trial patients from 41 nuclear medicine departments in Germany and Czech Republic were screened for aBAT. The occurrence of aBAT was analyzed with patient characteristics (age, sex, body mass index, predisposition to aBAT), weather data at the day of 18F-FDG PET scanning as well as the preventive measures taken. Potentially important factors from univariate analyses were included into a logistic regression model. Warming as a preventive measure was used in 243 18F-FDG-PET scans, propranolol was administered in 36, warming and propranolol were combined in 84, and no preventive measures were taken in 165 scans. Whereas age, sex and body mass index had no clear impact, there was an individual predisposition to aBAT. Logistic regression model revealed that the frequency of aBAT mainly depends on the outside temperature (p = 0.005) and can be effectively reduced by warming (p = 0.004), the administration of unselective beta-blocker or the combination of both. Warming is a simple, cheap and non-invasive method to reduce the frequency of aBAT. However, the effect of warming decreases with increasing outside temperatures. Administration of propranolol seems to be equally effective and provides advantages whenever the positive effect of warming is compromised. The combination of both preventive measures could have an additive effect.

Deep-learning based classification of a tumor marker for prognosis on Hodgkin's disease

PURPOSE

Hodgkin's disease is a common malignant disorder in adolescent patients. Although most patients are cured, approximately 10%-15% of patients experience a relapse or have resistant disease. Furthermore, there are no definitive molecular predictors for early identification of patients at high risk of treatment failure to first line therapy. The aim of this study was to evaluate the deep learning-based classifier model of medical image classification to predict clinical outcome that may help in appropriate therapeutic decisions.

METHODS

Eighty-three FFPE biopsy specimens from patients with Hodgkin's disease were stratified according to the patient's qPET scores, stained with picrosirius red dye and digitalized by whole slide image scanning. The resulting whole slide images were cut into tiles and annotated by two classes based on the collagen fibers' degree of coloring with picrosirius red. The neural network (YOLOv4) was then trained with the annotated data. Training was performed with 30 cases. Prognostic power of the weakly stained picrosirius red fibers was evaluated with 53 cases. The same neural network was trained with MMP9 stained tissue slides from the same cases and the quantification results were compared with the variant from the picrosirius red cases.

RESULTS

There was a weak monotonically increasing relationship by parametric ANOVA between the qPET groups and the percentages of weakly stained fibers (p = .0185). The qPET-positive cases showed an average of 18% of weakly stained fibers, and the qPET-negative cases 10%-14%. Detection performance showed an AUC of 0.79.

CONCLUSIONS

Picrosirius red shows distinct associations as a prognostic metric candidate of disease progression in Hodgkin's disease cases using whole slide images but not sufficiently as a prognostic device.

Significance of E-lesions in Hodgkin lymphoma and the creation of a new consensus definition: a report from SEARCH

The International Staging Evaluation and Response Criteria Harmonization for Childhood, Adolescent, and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) seeks to provide an appropriate, universal differentiation between E-lesions and stage IV extranodal disease in Hodgkin lymphoma (HL). A literature search was performed through the PubMed and Google Scholar databases using the terms "Hodgkin disease," and "extranodal," "extralymphatic," "E lesions," "E stage," or "E disease." Publications were reviewed for the number of participants; median age and age range; diagnostic modalities used for staging; and the definition, incidence, and prognostic significance of E-lesions. Thirty-six articles describing 12 640 patients met the inclusion criteria. Most articles reported staging per the Ann Arbor (72%, 26/36) or Cotswolds modification of the Ann Arbor staging criteria (25%, 9/36), and articles rarely defined E-lesions or disambiguated "extranodal disease." The overall incidence of E-lesions for patients with stage I-III HL was 11.5% (1330/11 602 unique patients). Available stage-specific incidence analysis of 3888 patients showed a similar incidence of E-lesions in stage II (21.2%) and stage III (21.9%), with E-lesions rarely seen with stage I disease (1.1%). E-lesions likely remain predictive, but we cannot unequivocally conclude that identifying E-lesions in HL imparts prognostic value in the modern era of the more selective use of targeted radiation therapy. A harmonized E-lesion definition was reached based on the available evidence and the consensus of the SEARCH working group. We recommend that this definition of E-lesion be applied in future clinical trials with explicit reporting to confirm the prognostic value of E-lesions.

Nivolumab plus Brentuximab vedotin +/- bendamustine combination therapy: a safe and effective treatment in pediatric recurrent and refractory classical Hodgkin lymphoma

Introduction

Classical Hodgkin lymphoma (cHL) is the most common pediatric lymphoma. Approximately 10% of patients develop refractory or recurrent disease. These patients are treated with intensive chemotherapy followed by consolidation with radiotherapy or high-dose chemotherapy and autologous stem cell reinfusion. Although this treatment is effective, it comes at the cost of severe long-term adverse events, such as reduced fertility and an increased risk of secondary cancers. Recently, promising results of inducing remission with the immune checkpoint inhibitor nivolumab (targeting PD-1) and the anti-CD30 antibody-drug conjugate Brentuximab vedotin (BV) +/- bendamustine were published.

Methods

Here we describe a cohort of 10 relapsed and refractory pediatric cHL patients treated with nivolumab + BV +/- bendamustine to induce remission prior to consolidation with standard treatment.

Results and discussion

All patients achieved complete remission prior to consolidation treatment and are in ongoing complete remission with a median follow-up of 25 months (range: 12 to 42 months) after end-of-treatment. Only one adverse event of CTCAE grade 3 or higher due to nivolumab + BV was identified. Based on these results we conclude that immunotherapy with nivolumab + BV +/- bendamustine is an effective and safe treatment to induce remission in pediatric R/R cHL patients prior to standard consolidation treatment. We propose to evaluate this treatment further to study putative long-term toxicity and the possibility to reduce the intensity of consolidation treatment.