Circulating tumor DNA reveals genetics, clonal evolution, and residual disease in classical Hodgkin lymphoma

Early serum TARC reduction predicts prognosis in advanced-stage Hodgkin lymphoma patients treated with a PET-adapted strategy

Among patients with advanced-stage classical Hodgkin lymphoma (cHL) receiving ABVD chemotherapy, PET performed after the first two treatment cycles (PET-2) has prognostic value. However, 15% of patients with a negative PET-2 will experience treatment failure. Here we prospectively evaluated serum thymus and activation-regulated chemokine (TARC) levels, to improve risk assessment in patients treated according to HD0607 PET-driven trial (#NCT00795613). In 266 patients with available serum samples, who have agreed to participate in a sub-study for assessment of the role of TARC monitoring, serum TARC levels were measured at baseline and at time of PET-2 by commercially available ELISA test kits. The primary end-point was to evaluate the association between TARC after 2 ABVD cycles and PFS. Median TARC-2 values were significantly higher in PET-2-positive patients compared to PET-2-negative patients (P = .001), and in patients with treatment failure compared to those in continuous CR (P = .01). The 4-year PFS significantly differed between patients with TARC-2 >800 pg/mL vs ≤800 pg/mL (64% vs 86%, P = .0001). Moreover, among PET-2-negative patients, elevated TARC-2 identified those with a worse prognosis (74% vs 89%; P = .01). In multivariable analysis, TARC-2 >800 pg/mL was a significant independent predictor of PFS in the whole study population (HR 2.39, P = .004) and among the PET-2-negative patients (HR 2.49, P = .02). In conclusion, our results indicate that TARC-2 serum levels above 800 pg/mL suggest the need for a stringent follow-up in PET-2-negative patients, and the evaluation of new drugs in PET-2-positive, who will likely fail to respond to intensification with escalated BEACOPP.

The immune landscape and response to immune checkpoint blockade therapy in lymphoma

The clinical development of effective cancer immunotherapies, along with advances in genomic analysis, has led to the identification of tumor environmental features that predict for sensitivity to immune checkpoint blockade therapy (CBT). Early-phase clinical trial results have demonstrated the remarkable effectiveness of CBT in specific lymphoma subtypes, including classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma. Conversely, CBT has been relatively disappointing in follicular lymphoma and diffuse large B-cell lymphoma. These clinical observations, coupled with important scientific discoveries, have uncovered salient features of the lymphoma microenvironment that correlate with immunotherapy response in patients. For example, classical Hodgkin lymphoma is characterized by an inflammatory environment, genetic alterations that facilitate escape from immune attack, and sensitivity to PD-1 blockade therapy. On the other hand, for lymphomas in which measures of immune surveillance are lacking, including follicular lymphoma and most diffuse large B-cell lymphomas, anti-PD-1 therapy has been less effective. An improved understanding of the immune landscapes of these lymphomas is needed to define subsets that might benefit from CBT. In this article, we describe the immune environments associated with major B-cell lymphomas with an emphasis on the immune escape pathways orchestrated by these diseases. We also discuss how oncogenic alterations in lymphoma cells may affect the cellular composition of the immune environment and ultimately, vulnerability to CBT. Finally, we highlight key areas for future investigation, including the need for the development of biomarkers that predict for sensitivity to CBT in lymphoma patients.

Hodgkin lymphoma

Hodgkin lymphoma (HL) is a B cell lymphoma characterized by few malignant cells and numerous immune effector cells in the tumour microenvironment. The incidence of HL is highest in adolescents and young adults, although HL can affect elderly individuals. Diagnosis is based on histological and immunohistochemical analyses of tissue from a lymph node biopsy; the tissue morphology and antigen expression profile enable classification into one of the four types of classic HL (nodular sclerosis, mixed cellularity, lymphocyte-depleted or lymphocyte-rich HL), which account for the majority of cases, or nodular lymphocyte-predominant HL. Although uncommon, HL remains a crucial test case for progress in cancer treatment. HL was among the first systemic neoplasms shown to be curable with radiation therapy and multiagent chemotherapy. The goal of multimodality therapy is to minimize lifelong residual treatment-associated toxicity while maintaining high levels of effectiveness. Recurrent or refractory disease can be effectively treated or cured with high-dose chemotherapy followed by autologous haematopoietic stem cell transplantation, and prospective trials have demonstrated the potency of immunotherapeutic approaches with antibody-drug conjugates and immune checkpoint inhibitors. This Primer explores the wealth of information that has been assembled to understand HL; these updated observations verify that HL investigation and treatment remain at the leading edge of oncological research.

Plasma circulating tumor DNA assessment reveals KMT2D as a potential poor prognostic factor in extranodal NK/T-cell lymphoma

Background

The early detection of tumors upon initial diagnosis or during routine surveillance is important for improving survival outcomes. Here, we investigated the feasibility and clinical significance of circulating tumor DNA (ctDNA) detection for Extranodal NK/T-cell lymphoma, nasal type (ENTKL).

Methods

The plasma ctDNA assessment was based on blood specimens collected from 65 newly diagnosed patients with ENKTL in the hematology medical center of Xinqiao Hospital. Longitudinal samples collected under chemotherapy were also included. The gene mutation spectrum of ENKTL was analyzed via next generation sequencing.

Results

We found that the most frequently mutated genes were KMT2D (23.1%), APC (12.3%), ATM (10.8%), ASXL3 (9.2%), JAK3 (9.2%), SETD2 (9.2%), TP53 (9.2%) and NOTCH1 (7.7%). The mutation allele frequencies of ATM and JAK3 were significantly correlated with the disease stage, and mutated KMT2D, ASXL3 and JAK3 were positively correlated with the metabolic tumor burden of the patients. Compared with the tumor tissue, ctDNA profiling showed good concordance (93.75%). Serial ctDNA analysis showed that treatment with chemotherapy could decrease the number and mutation allele frequencies of the genes. Compared with PET/CT, ctDNA has more advantages in tracking residual disease in patients. In addition, patients with mutated KMT2D had higher expression compared with those with wild type, and mutated KMT2D predicted poor prognosis.

Conclusion

Our results unveil the mutation spectrum of ENKTL patients' plasma, which can be used to monitor the disease status of the patients exactly, and KMT2D is the most frequently mutated gene with prognosis prediction value. The application of ctDNA sequencing can provide precision treatment strategies for patients.

Trial registration

This study is registered with chictr.org (ChiCTR1800014813, registered 7 February, 2018-Retrospectively registered).

Quantitative Analysis and Monitoring of EZH2 Mutations Using Liquid Biopsy in Follicular Lymphoma

Recent advances in molecular technologies enable sensitive and quantitative assessment of circulating tumor DNA, offering a noninvasive disease monitoring tool for patients with malignant disorders. Here, we demonstrated on four follicular lymphoma cases that circulating tumor DNA based EZH2 mutation analysis performed by a highly sensitive droplet digital PCR method may be a valuable treatment monitoring approach in EZH2 mutant follicular lymphoma. EZH2 variant allele frequencies changed in parallel with the volume of metabolically active tumor sites observed on 18F-fluorodeoxyglucose positron emission tomography combined with computer tomography (PET-CT) scans. Variant allele frequencies of EZH2 mutations decreased or were eliminated rapidly upon successful treatment, with treatment failure being associated with elevated EZH2 variant allele frequencies. We also demonstrated spatial heterogeneity in a patient with two different EZH2 mutations in distinct anatomical sites, with both mutations simultaneously detected in the liquid biopsy specimen. In summary, circulating tumor DNA based EZH2 mutation analysis offers a rapid, real-time, radiation-free monitoring tool for sensitive detection of EZH2 mutations deriving from different anatomical sites in follicular lymphoma patients receiving immunochemotherapy.

Routine next generation sequencing of lymphoid malignancies: clinical utility and challenges from a 3-Year practical experience

Since 2016, a next-generation sequencing (NGS) panel targeting 68 genes frequently mutated in lymphoid malignancies is an accredited part of routine diagnostics at the Institute of Pathology in Basel, Switzerland. Here, we retrospectively evaluate the feasibility and utility of integrating this NGS platform into routine practice on 80 diagnostic cases of lymphoid proliferations. NGS analysis was useful in most instances, yielding a diagnostically, predictively and/or prognostically meaningful result. In 35 out of the 50 cases, in which conventional histopathological evaluation remained indecisive, molecular subtyping with the NGS panel was helpful to either confirm or support the favored diagnosis, enable a differential diagnosis, or seriously question a suspected diagnosis. A total of 61 actionable or potentially actionable mutations in 34 out of 80 cases that might have enabled patient selection for targeted therapies was detected. NGS panel analysis had implications for prognosis in all 15 cases interrogated for risk assessment.

PET-adapted approaches to primary therapy for advanced Hodgkin lymphoma

Recent results of randomized phase III studies of FDG-PET-adapted therapy for advanced Hodgkin lymphoma (HL) have clearly demonstrated benefit to alteration of treatment according to interim response, in particular regarding reducing toxicity while maintaining efficacy. However, these studies have differences in design including initial chemotherapy regimen, PET response criteria, patient populations enrolled, and inclusion of radiation, and report different results regarding efficacy and toxicities, which makes cross-trial comparisons difficult. Practitioners are presented with deciding which of these approaches will provide the optimum outcome, balancing toxicity and efficacy, and for which patient with advanced-stage HL. This review summarizes the observations reported from these trials and provides context to help guide physicians and patients in treatment decisions for advanced HL.

Methodological framework for radiomics applications in Hodgkin's lymphoma

BACKGROUND

According to published data, radiomics features differ between lesions of refractory/relapsing HL patients from those of long-term responders. However, several methodological aspects have not been elucidated yet.

PURPOSE

The study aimed at setting up a methodological framework in radiomics applications in Hodgkin's lymphoma (HL), especially at (a) developing a novel feature selection approach, (b) evaluating radiomic intra-patient lesions' similarity, and (c) classifying relapsing refractory (R/R) vs non-(R/R) patients.

METHODS

We retrospectively included 85 patients (male:female = 52:33; median age 35 years, range 19-74). LIFEx (www.lifexsoft.org) was used for [18F]FDG-PET/CT segmentation and feature extraction. Features were a-priori selected if they were highly correlated or uncorrelated to the volume. Principal component analysis-transformed features were used to build the fingerprints that were tested to assess lesions' similarity, using the silhouette. For intra-patient similarity analysis, we used patients having multiple lesions only. To classify patients as non-R/R and R/R, the fingerprint considering one single lesion (fingerprint_One) and all lesions (fingerprint_All) was tested using Random Undersampling Boosting of Tree Ensemble (RUBTE).

RESULTS

HL fingerprints included up to 15 features. Intra-patient lesion similarity analysis resulted in mean/median silhouette values below 0.5 (low similarity especially in the non-R/R group). In the test set, the fingerprint_One classification accuracy was 62% (78% sensitivity and 53% specificity); the classification by RUBTE using fingerprint_All resulted in 82% accuracy (70% sensitivity and 88% specificity).

CONCLUSIONS

Lesion similarity analysis was developed, and it allowed to demonstrate that HL lesions were not homogeneous within patients in terms of radiomics signature. Therefore, a random target lesion selection should not be adopted for radiomics applications. Moreover, the classifier to predict R/R vs non-R/R performed the best when all the lesions were used.

Potential of Circulating Tumor DNA for the Management of Patients With Lymphoma

The characterization of circulating tumor-derived DNA (ctDNA) has recently emerged in the field of oncology as a powerful method to identify tumor-specific genetic aberrations using peripheral blood testing. Several technical precautions are needed at the pre-analytic stage (given the short half-life of free nucleic acids in plasma), and numerous techniques-with different sensitivities-are available to identify these molecular aberrations, ranging from the detection of single point mutations to extended genetic screening panels. Although a "liquid biopsy" cannot be substituted for the pathological examination of tissue specimens for diagnostic purposes, it can sometimes complement pathology results or serve as a proxy approach for particular lymphoma presentations where biopsies are sometimes difficult to perform. Moreover, ctDNA testing can characterize, at diagnosis or during treatment, mutations that may contribute to the choice of an optimal targeted therapy (such as Bruton tyrosine kinase or EZH2 inhibitors) or detect the emergence of resistance to those therapies. High levels of ctDNA before treatment appear to be correlated with advanced disease stages and prognosis in diffuse large B-cell and follicular lymphomas. Real-time follow-up of ctDNA levels during therapy in several lymphoma subtypes (diffuse large B-cell and Hodgkin lymphomas) has been explored: preliminary studies have demonstrated that this monitoring technique can predict clinical outcomes (end of treatment response and risk of progression after treatment completion) and that this approach may complement the information provided by metabolic imaging assessments. Technical standardization and careful prospective evaluation of the role of ctDNA monitoring in clinical studies represent current important challenges to allowing its application in routine practice.

Utility of Routine Surveillance Laboratory Testing in Detecting Relapse in Patients With Classic Hodgkin Lymphoma in First Remission: Results From a Large Single-Institution Study

PURPOSE

Classic Hodgkin lymphoma is highly curable with contemporary therapy. Although the limited role of surveillance imaging to detect early relapse for patients in complete remission at the end of therapy is well established, there is a paucity of data regarding role of laboratory testing in this setting.

METHODS

Patients with newly diagnosed classic Hodgkin lymphoma uniformly treated with the Stanford V regimen from 1998-2014 and in complete remission for at least 3 months were identified in a single-center institutional database. Laboratory tests categorized by Common Terminology Criteria for Adverse Events v4.03 as grade 2 or higher were considered abnormal. Primary analysis included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of surveillance laboratory tests for predicting relapse in the first 3 years after end of treatment.

RESULTS

Among 235 eligible patients, 24 (10.2%) patients ultimately relapsed. In the first 3 years after end of therapy, the mean number of surveillance blood draws per patient was 7.1, (range, 1-13). These 1,661 surveillance blood draws included 4,684 individual laboratory tests, comprising 1,609 CBCs, 1,578 metabolic panels, and 1,497 erythrocyte sedimentation rates. None of the biopsies confirming relapses were prompted by any abnormal laboratory finding. The sensitivity of any surveillance laboratory test for detecting relapse within 3 years of end of treatment was 72.7% (95% CI, 49.8% to 89.3%), specificity 22.6% (95% CI, 17.2% to 28.9%), yielding a PPV of 8.9% (95% CI, 7.0% to 11.3%) and NPV of 88.9% (95% CI, 79% to 94%).

CONCLUSION

Our study found limited clinically meaningful utility for routine surveillance laboratory testing in detecting relapse in patients with complete remission at end of treatment. Our results warrant consideration of modifications to current practice guidelines.

Diagnostic utility of STAT6YE361 expression in classical Hodgkin lymphoma and related entities

Although the distinction of classical Hodgkin lymphoma from nodular lymphocyte predominant Hodgkin lymphoma using morphology and immunostains is straightforward in most instances, occasional cases pose diagnostic challenge. We sought to determine the utility of the novel YE361 STAT6 rabbit monoclonal antibody in Hodgkin lymphoma and diagnostically challenging B- and T-cell non-Hodgkin lymphoma entities with Hodgkin-like features. Cases from seven institutions included: 57 classical Hodgkin lymphomas (31% EBV+), 34 nodular lymphocyte predominant Hodgkin lymphomas, 34 mimicking B- and T-cell non-Hodgkin lymphomas, and 7 reactive lymphoproliferations. After review of histology, STAT6^YE361 immunostaining was performed. The intensity and spatial localization of immunopositivity was assessed in neoplastic cells. Additional FISH for programmed death ligand-1 (PD-L1) was performed in one patient in paired treatment-naive and relapse biopsy tissues. Two STAT6^YE361 immunopositive cases were examined by whole-exome sequencing after flow sorting to assess mutations in STAT6 pathway genes. Most classical Hodgkin lymphomas showed nuclear staining for STAT6^YE361 [46/57 cases (80%)] on Hodgkin cells. Staining was exclusively nuclear in a minority [12/46 (26%)], while dual nuclear and cytoplasmic localization was more common [34/46 (74%)]. In contrast, all nodular lymphocyte predominant Hodgkin lymphomas [0/34 (0%)] were negative for nuclear STAT6^YE361 staining on the lymphocyte predominant cells. Within B- and T-cell non-Hodgkin lymphomas, nuclear STAT6^YE361 was seen in: B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma, and in primary mediastinal large B-cell lymphoma. Strong PD-L1 gene amplification was noted in the paired cHL and relapse B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma, although STAT6^YE361 was negative in both biopsies. Whole-exome sequencing identified mutations in B2M, XPO1, and ITPKB as well CISHP213L (in the STAT pathway) in one classical Hodgkin lymphoma patient positive for nuclear STAT6^YE361 although no underlying STAT6 mutations were observed in either sample examined. STAT6^YE361 nuclear staining has 100% positive predictive value and 85.7% negative predictive value in confirming or excluding classical Hodgkin lymphoma diagnosis in the distinction from nodular lymphocyte predominant Hodgkin lymphoma and other benign and malignant entities.

Digital PCR: A Reliable Tool for Analyzing and Monitoring Hematologic Malignancies

The digital polymerase chain reaction (dPCR) is considered to be the third-generation polymerase chain reaction (PCR), as it yields direct, absolute and precise measures of target sequences. dPCR has proven particularly useful for the accurate detection and quantification of low-abundance nucleic acids, highlighting its advantages in cancer diagnosis and in predicting recurrence and monitoring minimal residual disease, mostly coupled with next generation sequencing. In the last few years, a series of studies have employed dPCR for the analysis of hematologic malignancies. In this review, we will summarize these findings, attempting to focus on the potential future perspectives of the application of this promising technology.

An update on disease biomarkers for Hodgkin lymphoma

Introduction: Hodgkin Lymphoma (HL) carries an overall excellent prognosis for young patients treated with multimodal therapy. Predicting an individual patient's prognosis is currently heavily dependent on imaging modalities such as Positron Emission Tomography (PET).Areas covered: Potential biomarkers from serum, tissue, circulating nucleic acids and non-tumor derived cells have all been reported to be of prognostic relevance in HL. We review a range of these biomarkers and discuss the integration of new biomarkers into individualized patient care.Expert opinion: Better prognostic markers are needed to predict an individuals response to HL therapy. Interim PET-scan improves the ability to predict long-term treatment responders. However, it is our opinion that supplementation of PET results with additional biomarkers (including circulating tumor DNA, protein biomarkers, tissue genotyping and metabolic tumor volume) are likely to improve risk stratification for future patients with HL.

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.

Imaging Surveillance of Limited-stage Classic Hodgkin Lymphoma Patients After PET-CT-documented First Remission

INTRODUCTION

Early stage Hodgkin lymphoma (ESHL) is highly curable; however, 10% to 15% of patients experience relapse. We examined the utilization of follow-up imaging for patients with ESHL who achieved a metabolic complete response after upfront therapy.

MATERIALS AND METHODS

The records of adult patients treated at a single institution between 2003 and 2014 were reviewed. Positron emission tomography-computed tomography (PET-CT) and CT scan frequency was quantified during the 2 years following treatment and subsequent visits beyond 2 years.

RESULTS

The study cohort contained 179 patients. The median age was 31 years; bulky disease was present in 30%. ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) or AVD (doxorubicin, vinblastine, and dacarbazine) was given in 97%; 75% received radiation therapy. At a median follow-up of 6.9 years, the 5-year progression-free and overall survival rates were 93.7% and 98.1%, respectively. Relapse occurred in 5% (n = 9) of patients at a median of 9.1 months (range, 4.6-27.2 months) from therapy. Two patients presented with symptoms prompting imaging in follow-up. Within 2 years after therapy, 376 PET-CT scans and 3325 CT scans were performed, yielding an average of 2.1 PET-CTs and 18.6 CTs per patient. Of the initial 179 patients, 113 had follow-up conducted beyond 2 years post-therapy; an average of 2.7 PET-CTs and 33.2 CTs were performed. In the 2-year post-therapy period, 463 scans were performed per relapse detected.

CONCLUSION

In this cohort of patients with ESHL who responded completely to frontline therapy, the relapse rate was low. Routine imaging surveillance lacks clinical benefit in this patient population.

Genetic alterations in B cell lymphoma subtypes as potential biomarkers for noninvasive diagnosis, prognosis, therapy, and disease monitoring

Neoplastic transformation of germinal center B (GCB) cells may give rise to a variety of different B cell lymphoma subtypes, most of which show substantial heterogeneity in terms of genetic alterations and clinical features. The mutations observed in cancer-related genes in GCB cells are related to abnormalities in the immunogenetic mechanisms associated with germinal center reaction. Recent studies have rapidly identified genomic alterations in B cell lymphomas that may be useful for better subclassification, noninvasive diagnosis, and prediction of response to therapy. The WHO recognizes different lymphoma subsets classified within 2 major categories of B cell lymphoma: Hodgkin’s lymphoma (HL) and B cell non-Hodgkin’s lymphoma (NHL), each with distinct genetic aberrations, including chromosomal translocations, copy number abnormalities, or point mutations. Next-generation sequencing-based technologies have allowed cancer researchers to identify somatic mutations and gene expression signatures at a rapid pace so that novel diagnostic or prognostic biomarkers, as well as therapeutic targets, can be discovered much faster than before. Indeed, deep sequencing studies have recently revealed that lymphoma-specific somatic mutations may be detected in cell-free circulating DNA obtained from the peripheral blood of B cell lymphoma patients, suggesting the possibility of minimally invasive diagnosis, monitoring, and predicting response to therapy of B cell lymphoma patients. In this study, the current status of the recurrent genetic aberrations observed during diagnosis and/or relapse in HL and the major subtypes of B cell NHL (i.e. diffuse large B cell lymphoma, follicular lymphoma, mantle cell lymphoma, and Burkitt lymphoma) are discussed to shed light on their potential use as noninvasive diagnostic or prognostic biomarkers and to reveal their role in lymphomagenesis as a target in therapy for newly diagnosed and chemotherapy-resistant cases.

Prognostication with circulating tumor DNA: is it ready for prime time?

Emerging methods to detect tumor-derived DNA in the blood plasma of patients with lymphomas-so-called "circulating tumor DNA" (ctDNA)-have the potential to change the way in which lymphoma is diagnosed and managed in the clinic. The possible applications for ctDNA are numerous, including mutation genotyping, response monitoring, and detection of minimal residual disease during a time of radiographic remission. This article discusses the methodology for detecting ctDNA in aggressive B-cell lymphomas, including digital polymerase chain reaction, targeted sequencing of immunoglobulin receptors, and targeted next-generation sequencing. The advantages of each of these methods are also compared, with a focus on promising clinical applications. These include identification of molecular subtypes (eg, cell-of-origin and double-hit lymphomas) from pretreatment plasma, molecular response prediction after an initial course of therapy, and early detection of relapsing disease prior to clinical relapse. Finally, this article discusses the challenges in implementing ctDNA assays in the clinic today, including possible solutions to these challenges.

Development and verification of a nomogram for prediction of recurrence-free survival in clear cell renal cell carcinoma

Nowadays, gene expression profiling has been widely used in screening out prognostic biomarkers in numerous kinds of carcinoma. Our studies attempt to construct a clinical nomogram which combines risk gene signature and clinical features for individual recurrent risk assessment and offer personalized managements for clear cell renal cell carcinoma. A total of 580 differentially expressed genes (DEGs) were identified via microarray. Functional analysis revealed that DEGs are of fundamental importance in ccRCC progression and metastasis. In our study, 338 ccRCC patients were retrospectively analysed and a risk gene signature which composed of 5 genes was obtained from a LASSO Cox regression model. Further analysis revealed that identified risk gene signature could usefully distinguish the patients with poor prognosis in training cohort (hazard ratio [HR] = 3.554, 95% confidence interval [CI] 2.261‐7.472, P < .0001, n = 107). Moreover, the prognostic value of this gene‐signature was independent of clinical features (P = .002). The efficacy of risk gene signature was verified in both internal and external cohorts. The area under receiver operating characteristic curve of this signature was 0.770, 0.765 and 0.774 in the training, testing and external validation cohorts, respectively. Finally, a nomogram was developed for clinicians and did well in the calibration plots. This nomogram based on risk gene signature and clinical features might provide a practical way for recurrence prediction and facilitating personalized managements of ccRCC patients after surgery.

Cell-free DNA and the monitoring of lymphoma treatment

The technique of cell-free DNA (cfDNA) analysis, also called liquid biopsy, has been developed over the past several years to serve as a minimal residual disease tool, as has already been done with reliability and robustness in acute leukemias. This technique has important theoretical advantages, including the simplicity of acquiring blood samples, which can easily be repeated over time, its noninvasive and quantitative nature, which provides results consistent with the results obtained from tumor genomic DNA, and its speed and low cost. cfDNA analysis, as the leading tool to quantify somatic mutations, is a major technological leap in the noninvasive management of lymphomas. This technology may empower monitoring and treatment adjustment in real time and enable the quick detection of refractory lymphomas and resistance to routine therapies. Here, we summarize the results that have established the clinical relevance of cfDNA in diagnostic and prognostic stratification and the monitoring of lymphoma treatments.

Immune and Inflammatory Cells of the Tumor Microenvironment Represent Novel Therapeutic Targets in Classical Hodgkin Lymphoma

Classical Hodgkin Lymphoma (cHL) is a B-cell malignancy that, typically, responds well to standard therapies. However, patients who relapse after standard regimens or are refractory to induction therapy have a dismal outcome. The implementation of novel therapies such as the anti-CD30 monoclonal antibody Brentuximab Vedotin and immune checkpoint inhibitors has provided curative options for many of these patients. Nonetheless, responses are rarely durable, emphasizing the need for new agents. cHL is characterized by a unique microenvironment in which cellular and humoral components interact to promote tumor survival and dissemination. Knowledge of the complex composition of cHL microenvironment is constantly evolving; in particular, there is growing interest in certain cell subsets such as tumor-associated macrophages, myeloid-derived suppressor cells and neutrophils, all of which have a relevant role in the pathogenesis of the disease. The unique biology of the cHL microenvironment has provided opportunities to develop new drugs, many of which are currently being tested in preclinical and clinical settings. In this review, we will summarize novel insights in the crosstalk between tumor cells and non-malignant inflammatory cells. In addition, we will discuss the relevance of tumor-microenvironment interactions as potential therapeutic targets.

Five-year follow-up of SWOG S0816: limitations and values of a PET-adapted approach with stage III/IV Hodgkin lymphoma

Patients with advanced-stage Hodgkin lymphoma (HL) demonstrated excellent 2-year progression-free survival (PFS) after receiving positron emission tomography (PET)-adapted therapy on SWOG S0816. Patients received 2 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Patients achieving complete response (CR) on PET scan following cycle 2 of ABVD (PET2) continued 4 additional cycles of ABVD. Patients not achieving CR on PET2 were switched to escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP) for 6 cycles. After a median follow-up of 5.9 years, a subset of 331 eligible patients with central review of PET2 was analyzed. PET2 was negative in 82% and positive in 18%. For all patients, the estimated 5-year PFS and OS was 74% (95% confidence interval [CI], 69%-79%) and 94% (95% CI, 91%-96%), respectively. For PET2- and PET2+ patients, the 5-year PFS was 76% (95% CI, 70%-81%) and 66% (95% CI, 52%-76%), respectively. Seven (14%) and 6 (2%) patients reported second cancers after treatment with eBEACOPP and ABVD, respectively (P = .001). Long-term OS of HL patients treated on S0816 remains high. Nearly 25% of PET2- patients experienced relapse events, demonstrating limitations ABVD therapy and of the negative predictive value of PET2. In PET2+ patients who received eBEACOPP, PFS was favorable, but was associated with a high rate of second malignancies compared with historical controls. Our results emphasize the importance of long-term follow-up, and the need for more efficacious and less toxic therapeutic approaches for advanced-stage HL patients. This trial was registered at www.clinicaltrials.gov as #NCT00822120.

Closing the survivorship gap in children and adolescents with Hodgkin lymphoma

The treatment of Hodgkin lymphoma (HL) is one of early success. However, disease-free survival (DFS) does not reflect latent organ injury and its impact on health status and well-being beyond 5 years. In fact, we are at a crossroads, in terms of needing individualized approaches to maintain DFS, while minimizing late effects and preserving health-related quality of life (HRQoL). Premature morbidity and mortality translate to a high societal cost associated with the potential number of productive life years ahead in this population who are young at diagnosis. The discordance between short-term lymphoma-free survival and long-term health and HRQoL creates a "survivorship gap" which can be characterized for individuals and for subgroups of patients. The current review delineates contributors to compromised outcomes and health status in child and adolescent (paediatric) HL and frames the survivorship gap in terms of primary and secondary prevention. Primary prevention aims to titrate therapy. Secondary prevention entails strategies to intervene against late effects. Bridging the survivorship gap will be attained with enhanced knowledge of and attention to biology of the tumour and microenvironment, host genetic factors, HRQoL and sub-populations with disparate outcomes.

Novel Biomarker Approaches in Classic Hodgkin Lymphoma

Classic Hodgkin lymphoma (cHL) is one of the most common lymphomas in the Western world. Advances in the management of cHL have led to high cure rates exceeding 80%. Nevertheless, relapse or refractory disease in a subset of patients and treatment-related toxicity still represents unsolved clinical problems. The introduction of targeted treatments such as PD-1 blockade and the CD30 antibody drug conjugate, brentuximab vedotin, has broadened treatment options in cHL, emphasizing the critical need to identify biomarkers with the goal to provide rationales for treatment selection, increase effective drug utilization, and minimize toxicity. The unique biology of cHL featuring low abundant tumor cells and numerous nonmalignant immune cells in the tumor microenvironment can provide various types of promising biomarkers related to the tumor cells directly, tumor microenvironment cross-talk, and host immune response. Here, we comprehensively review novel biomarkers including circulating tumor DNA and gene expression-based prognostic models that might guide the ideal management of cHL in the future.

Resolving genetic heterogeneity in cancer

To a large extent, cancer conforms to evolutionary rules defined by the rates at which clones mutate, adapt and grow. Next-generation sequencing has provided a snapshot of the genetic landscape of most cancer types, and cancer genomics approaches are driving new insights into cancer evolutionary patterns in time and space. In contrast to species evolution, cancer is a particular case owing to the vast size of tumour cell populations, chromosomal instability and its potential for phenotypic plasticity. Nevertheless, an evolutionary framework is a powerful aid to understand cancer progression and therapy failure. Indeed, such a framework could be applied to predict individual tumour behaviour and support treatment strategies.

The STELLAR trial protocol: a prospective multicentre trial for Richter's syndrome consisting of a randomised trial investigation CHOP-R with or without acalabrutinib for newly diagnosed RS and a single-arm platform study for evaluation of novel agents in relapsed disease

BACKGROUND

Transformation of chronic lymphocytic leukaemia (CLL) to diffuse large B-cell lymphoma (DLCBL) type Richter's syndrome (RS) carries a dismal prognosis. Standard-of-care chemoimmunotherapy for de novo RS is inadequate with median survival of less than one year. Patients are frequently elderly or have co-morbidities limiting dose-intense chemotherapy. Treatment of relapsed/refractory (R/R) RS and RS emerging after CLL-directed therapy represent urgent unmet clinical needs. Agents targeting Bruton's tyrosine kinase (BTK) deliver improved outcomes for patients with high-risk CLL and expand effective treatments to frailer patients. Acalabrutinib is an oral, second-generation BTK inhibitor with a favourable toxicity profile and demonstrated activity in CLL and B-cell lymphomas. Combination of acalabrutinib with standard-of-care CHOP-R chemoimmunotherapy offers a sound rationale to test in a prospective trial for de novo RS.

METHODS

The prospective multicentre STELLAR study is designed in two elements, consisting of a randomised study to evaluate the safety and activity of CHOP-R chemoimmunotherapy in combination with acalabrutinib in newly diagnosed RS and single-arm studies of novel agents for other RS patient cohorts. Eligible patients with newly diagnosed DLBCL-type RS are randomised between six cycles of CHOP-R therapy and six cycles CHOP-R plus acalabrutinib, followed by acalabrutinib maintenance. The primary endpoint of the randomised component is progression free survival (PFS). Cohort 1 enrols RS patients with progressive disease following chemoimmunotherapy for acalabrutinib monotherapy. Patients with RS diagnosed while on ibrutinib may enrol in Cohort 2, a single-arm study of CHOP-R plus acalabrutinib. The primary endpoint for the single-arm studies is overall response rate (ORR). Secondary endpoints for all cohorts are overall survival (OS), quality of life and proportion of patients proceeding to stem cell transplantation. The study will be accompanied by exploratory analysis of the mutational landscape of RS and the relationship between dynamic changes in sequential circulating tumour DNA samples and clinical outcomes.

DISCUSSION

The STELLAR randomised trial evaluates the role of CHOP-R plus acalabrutinib in newly diagnosed RS patients. The single-arm platform studies enable the incorporation of promising novel therapies into the protocol. The STELLAR study has potential to identify novel biomarkers of treatment response in this high-risk malignancy.

TRIAL REGISTRATION

EudraCT: 2017-004401-40 , registered on the 31-Oct-2017. IRSCTN: https://www.isrctn.com/ISRCTN52839057 , registered on the 04-Mar-2019. ClinicalTrials.gov : NCT03899337 , registered on 02-April-2019.

Engineering Multidimensional Evolutionary Forces to Combat Cancer

With advances in technology and bioinformatics, we are now positioned to view and manage cancer through an evolutionary lens. This perspective is critical as our appreciation for the role of tumor heterogeneity, tumor immune compartment, and tumor microenvironment on cancer pathogenesis and evolution grows. Here, we explore recent knowledge on the evolutionary basis of cancer pathogenesis and progression, viewing tumors as multilineage, multicomponent organisms whose growth is regulated by subcomponent fitness relationships. We propose reconsidering some current tenets of the cancer management paradigm in order to take better advantage of crucial fitness relationships to improve outcomes of patients with cancer. SIGNIFICANCE: Tumor and tumor immune compartment and microenvironment heterogeneity, and their evolution, are critical disease features that affect treatment response. The impact and interplay of these components during treatment are viable targets to improve clinical response. In this article, we consider how tumor cells, the tumor immune compartment and microenvironment, and epigenetic factors interact and also evolve during treatment. We evaluate the convergence of these factors and suggest innovative treatment concepts that leverage evolutionary relationships to limit tumor growth and drug resistance.

Assessment of circulating tumor DNA in pediatric solid tumors: The promise of liquid biopsies

Circulating tumor DNA can be detected in the blood and body fluids of patients using ultrasensitive technologies, which have the potential to improve cancer diagnosis, risk stratification, noninvasive tumor profiling, and tracking of treatment response and disease recurrence. As we begin to apply "liquid biopsy" strategies in children with cancer, it is important to tailor our efforts to the unique genomic features of these tumors and address the technical and logistical challenges of integrating biomarker testing. This article reviews the literature demonstrating the feasibility of applying liquid biopsy to pediatric solid malignancies and suggests new directions for future studies.

Updates on Circulating Tumor DNA Assessment in Lymphoma

PURPOSE OF REVIEW

The use of circulating tumor DNA (ctDNA) for the purposes of diagnosis, prognosis, assessment of treatment response, and monitoring for relapse is a new and developing field in lymphoma. This review aims to summarize many of the most recent advances in ctDNA applications.

RECENT FINDINGS

Recent studies have demonstrated the use of ctDNA assessment across many lymphoma subtypes including diffuse large B-cell lymphoma, follicular lymphoma, Hodgkin lymphoma, and T-cell lymphoma. In addition, many novel applications of ctDNA assessment have been described such as the development of new prognostic models, investigation of clonal evolution and heterogeneity, early assessment of treatment response, and prediction of response to targeted therapy as a form of personalized medicine. The use of ctDNA has been shown to be feasible across many lymphoma subtypes and has shown significant promise for several new applications. Additional studies will be needed to validate these findings prior to routine use in clinical practice.

Translating insights into tumor evolution to clinical practice: promises and challenges

Accelerating technological advances have allowed the widespread genomic profiling of tumors. As yet, however, the vast catalogues of mutations that have been identified have made only a modest impact on clinical medicine. Massively parallel sequencing has informed our understanding of the genetic evolution and heterogeneity of cancers, allowing us to place these mutational catalogues into a meaningful context. Here, we review the methods used to measure tumor evolution and heterogeneity, and the potential and challenges for translating the insights gained to achieve clinical impact for cancer therapy, monitoring, early detection, risk stratification, and prevention. We discuss how tumor evolution can guide cancer therapy by targeting clonal and subclonal mutations both individually and in combination. Circulating tumor DNA and circulating tumor cells can be leveraged for monitoring the efficacy of therapy and for tracking the emergence of resistant subclones. The evolutionary history of tumors can be deduced for late-stage cancers, either directly by sampling precursor lesions or by leveraging computational approaches to infer the timing of driver events. This approach can identify recurrent early driver mutations that represent promising avenues for future early detection strategies. Emerging evidence suggests that mutational processes and complex clonal dynamics are active even in normal development and aging. This will make discriminating developing malignant neoplasms from normal aging cell lineages a challenge. Furthermore, insight into signatures of mutational processes that are active early in tumor evolution may allow the development of cancer-prevention approaches. Research and clinical studies that incorporate an appreciation of the complex evolutionary patterns in tumors will not only produce more meaningful genomic data, but also better exploit the vulnerabilities of cancer, resulting in improved treatment outcomes.

The emerging role of cell-free DNA as a molecular marker for cancer management

An increasing number of studies demonstrate the potential use of cell-free DNA (cfDNA) as a surrogate marker for multiple indications in cancer, including diagnosis, prognosis, and monitoring. However, harnessing the full potential of cfDNA requires (i) the optimization and standardization of preanalytical steps, (ii) refinement of current analysis strategies, and, perhaps most importantly, (iii) significant improvements in our understanding of its origin, physical properties, and dynamics in circulation. The latter knowledge is crucial for interpreting the associations between changes in the baseline characteristics of cfDNA and the clinical manifestations of cancer. In this review we explore recent advancements and highlight the current gaps in our knowledge concerning each point of contact between cfDNA analysis and the different stages of cancer management.

Progressive diffuse large B-cell lymphoma with TP53 gene mutation treated with chidamide-based chemotherapy

We attempted to explore novel treatment options for progressive diffuse large B-cell lymphoma (DLBCL) with TP53 mutation that has a poor response to rituximab-based immunochemotherapy. Herein, we report the case of a patient with DLBCL having TP53 mutation who showed progression following four cycles of rituximab-based immunochemotherapy but achieved sustained partial remission following chidamide-based chemotherapy. In vitro experiments performed using the DLBCL cell lines OCI-ly1 (LY1; mutant TP53), OCI-ly10 (LY10; wild-type TP53) and OCI-ly19 (LY19, wild-type TP53) demonstrated that chidamide is more potent against cells with mutant TP53 mutant than those with wild-type TP53. Moreover, chidamide can reduce the mRNA and protein expression levels of mutant TP53 and upregulate the surface expression of the CD20 antigen in lymphoma cells.

Ultrasensitive Detection of Circulating Tumor DNA in Lymphoma via Targeted Hybridization Capture and Deep Sequencing of Barcoded Libraries

Liquid biopsies are rapidly emerging as powerful tools for the early detection of cancer, noninvasive genomic profiling of localized or metastatic tumors, prompt detection of treatment resistance-associated mutations, and monitoring of therapeutic response and minimal residual disease in patients during clinical follow-up. Growing evidence strongly supports the utility of circulating tumor DNA (ctDNA) as a biomarker for the stratification and clinical management of lymphoma patients. However, ctDNA is diluted by variable amounts of cell-free DNA (cfDNA) shed by nonneoplastic cells causing a background signal of wild-type DNA that limits the sensitivity of methods that rely on DNA sequencing. Here, we describe an error suppression method for single-molecule counting that relies on targeted sequencing of cfDNA libraries constructed with semi-degenerate barcode adapters. Custom pools of biotinylated DNA baits for target enrichment can be designed to specifically track somatic mutations in one patient, survey mutation hotspots with diagnostic and prognostic value or be comprised of comprehensive gene panels with broad patient coverage in lymphoma. Such methods are amenable to track ctDNA levels during longitudinal liquid biopsy testing with high specificity and sensitivity and characterize, in real time, the genetic profiles of tumors without the need of standard invasive biopsies. The analysis of ultra-deep sequencing data according to the bioinformatics pipelines also described in this chapter affords to harness lower limits of detection for ctDNA below 0.1%.

Diagnosis of Hodgkin lymphoma in the modern era

The Hodgkin lymphomas are a family of unique lymphoma subtypes, in which the nature of the neoplastic cell was enigmatic for many years. Much of the mystery has been solved, with all forms now considered to be of B-cell origin, in most cases of germinal centre derivation. Today we recognize Hodgkin lymphoma as an eponym that encompasses multiple entities. One of the unifying themes is the major contribution from the tumour microenvironment. Both the character of the neoplastic cells and the nature of the immune environment are critical to accurate diagnosis. Moreover, an understanding of the molecular alterations that characterize both the neoplastic cells and their microenvironment have led to therapeutic advances, targeting both neoplastic and reactive components. Other conditions may foster a similar inflammatory milieu and lead to lymphoproliferations that mimic the Hodgkin lymphomas. In this review we provide an update on the diagnostic features of the various subtypes and include additional information relevant for prognostic evaluation and investigation of potential therapeutic targets. Additionally, we also discuss those conditions that often cause confusion in diagnosis and need to be distinguished from the Hodgkin lymphomas.

Therapeutic recommendations for early stage Hodgkin lymphomas

Combined modality treatment has been the standard option for the treatment of early stage Hodgkin lymphoma for several decades. Because of the high success rate and the risk of late toxicities, recent clinical trials have focused on reducing the treatment burden. Field and dose of radiotherapy, and number of cycles of chemotherapy have been successfully reduced, particularly for favourable early stage patients. However, the impact of these treatment reductions on the rate of secondary malignancies remains still unclear. Positron emission tomography-computed tomography (PET-CT) scanning has emerged as a very important tool for disease staging and end of treatment assessment. Interestingly, a PET performed after 2 cycles of ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) has been correlated with final outcome and was recently evaluated in a randomized clinical trial to evaluate individualized therapy based on PET response after 2 or 3 cycles of ABVD. These trials aimed to identify good prognosis (early PET-negative) patients who could be spared radiotherapy, but also patients with a bad prognosis (early PET-positive) who need more intensive treatment. More recently, new drugs, such as brentuximab vedotin and checkpoint inhibitors, have shown efficacy in relapsed/refractory patients and are currently under evaluation in early stage patients.

Risk-adapted therapy for advanced-stage Hodgkin lymphoma

More than 80% of patients with advanced-stage Hodgkin lymphoma are now cured with contemporary treatment approaches. The ongoing challenge is how to further improve outcomes by identifying both high-risk patients who may benefit from more intensive frontline therapy to reduce the risk of relapse as well as lower-risk patients who may do just as well with less intensive therapy. Numerous trials have used an interim positron emission tomography (PET) response-adapted approach to evaluate early escalation or deescalation of therapy for patients with a positive or negative interim PET scan, respectively. Recent trials have incorporated novel agents, including brentuximab vedotin (BV) and the immune checkpoint inhibitors, in the frontline setting. Based on results of the ECHELON-1 trial, the Food and Drug Administration approved BV in combination with adriamycin, vinblastine, and dacarbazine chemotherapy for stage III to IV Hodgkin lymphoma. Improved methods to assess higher risk at diagnosis using quantitative PET metrics, such as metabolic tumor volume and total lesion glycolysis, and incorporation of emerging biomarkers may further refine patient selection for more intensive upfront therapy. The ultimate goal is to achieve the highest level of efficacy for an individual patient while minimizing the short- and long-term toxicities.

Mutational Evolution in Relapsed Diffuse Large B-Cell Lymphoma

Current genomic models in diffuse large B-cell lymphoma (DLBCL) are based on single tumor biopsies, which might underestimate heterogeneity. Data on mutational evolution largely remains unknown. An exploratory study using whole exome sequencing on paired (primary and relapse) formalin fixed paraffin embedded DLBCL biopsies (n = 14) of 6 patients was performed to globally assess the mutational evolution and to identify gene mutations specific for relapse samples from patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone. A minority of the mutations detected in the primary sample (median 7.6%, range 4.8–66.2%) could not be detected in the matching relapse sample. Relapsed DLBCL samples showed a mild increase of mutations (median 12.5%, range 9.4–87.6%) as compared to primary tumor biopsies. We identified 264 genes possibly related to therapy resistance, including tyrosine kinases (n = 18), (transmembrane) glycoproteins (n = 73), and genes involved in the JAK-STAT pathway (n = 7). Among the potentially resistance related genes were PIM1, SOCS1, and MYC, which have been reported to convey a risk for treatment failure. In conclusion, we show modest temporal heterogeneity between paired tumor samples with the acquisition of new mutations and identification of genes possibly related to therapy resistance. The mutational evolution could have implications for treatment decisions and development of novel targeted drugs.

New Molecular Technologies for Minimal Residual Disease Evaluation in B-Cell Lymphoid Malignancies

The clearance of malignant clonal cells significantly correlates with clinical outcomes in many hematologic malignancies. Accurate and high throughput tools for minimal residual disease (MRD) detection are needed to overcome some drawbacks of standard molecular techniques; such novel tools have allowed for higher sensitivity analyses and more precise stratification of patients, based on molecular response to therapy. In this review, we depict the recently introduced digital PCR and next-generation sequencing technologies, describing their current application for MRD monitoring in lymphoproliferative disorders. Moreover, we illustrate the feasibility of these new technologies to test less invasive and more patient-friendly tissues sources, such as "liquid biopsy".

Determining the sequence of novel therapies in the treatment of relapsed Hodgkin's lymphoma

INTRODUCTION

Hodgkin's lymphoma (HL) accounts for about 10% of all lymphomas in the U.S.A. Exceptional progress has been made in the treatment of HL with complete response (CR) rates up to 94% in limited stage and 88% in advanced stage disease with regimens such as adriamycin, bleomycin, vinblastine, and dacarbazine in the frontline setting. Nevertheless, up to 10% of patients with limited stage disease and 20-30% of those with advanced stage HL relapse. In the last decade, newer agents such as brentuximab vedotin (BV) and checkpoint inhibitors have been approved by the FDA for treatment of patients with relapsed or refractory HL. As these newer agents are increasingly incorporated in both the frontline and relapsed settings, their optimal sequence becomes challenging for clinicians. Areas covered: This review will discuss the evidence behind the approval of BV and checkpoint inhibitors in HL and the appropriate sequence for using them in relapsed HL. Expert commentary: The appropriate sequence of BV and/or checkpoint inhibitors in the relapsed setting depends on the regimen used in the frontline setting.