Spatial phenotyping of nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B-cell lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma with sparse tumor B-cells and a favorable prognosis. Variant growth patterns of NLPHL, however, often show advanced stage, progression to T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) and a worse prognosis. We studied the tumor microenvironment (TME) of NLPHL and THRLBCL using highplex imaging and spatial profiling at the single cell level. Our findings show distinct differences in TME composition and spatial configuration that differ among typical and variant NLPHL and THRLBCL. Typical NLPHL show abundant helper T-cell subsets, while THRLBCL show abundant cytotoxic T-cells and macrophages. Tumor B-cell size and content is lowest in typical NLPHL, followed by variant NLPHL, and highest in THRLBCL, whereas an opposite trend characterized TME B-cells. CD4/CD8 double-positive T-cells are seen in all NLPHL but not in the majority of THRLBCL and are spatially distant from LP-cells and TFH-rosettes. The differences in macrophage/monocyte content in distinguishing NLPHL pattern E from THRLBCL is further corroborated in independent cohorts of cases. Our results validate the current approach to classification and in addition provide novel insights that could be leveraged to refine clinical management for patients with this spectrum of lymphomas.

Specific Polo-Like Kinase 1 Expression in Nodular Lymphocyte-Predominant Hodgkin Lymphoma Suggests an Intact Immune Surveillance Program

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare and relatively indolent B-cell lymphoma. Characteristically, the [lymphocyte-predominant (LP)] tumor cells are embedded in a microenvironment enriched in lymphocytes. More aggressive variants of mature B-cell and peripheral T-cell lymphomas exhibit nuclear expression of the polo-like kinase 1 (PLK1) protein, stabilizing MYC (alias c-myc) and associated with worse clinical outcomes. This study demonstrated expression of PLK1 in the LP cells in 100% of NLPHL cases (n = 76). In contrast, <5% of classic Hodgkin lymphoma cases (n = 70) showed PLK1 expression within the tumor cells. Loss-of-function approaches demonstrated that the expression of PLK1 promoted cell proliferation and increased MYC stability in NLPHL cell lines. Correlation with clinical parameters revealed that the increased expression of PLK1 was associated with advanced-stage disease in patients with NLPHL. A multiplex immunofluorescence panel coupled with artificial intelligence algorithms was used to correlate the composition of the tumor microenvironment with the proliferative stage of LP cells. The results showed that LP cells with PLK1 (high) expression were associated with increased numbers of cytotoxic and T-regulatory T cells. Overall, the findings demonstrate that PLK1 signaling increases NLPHL proliferation and constitutes a potential vulnerability that can be targeted with PLK1 inhibitors. An active immune surveillance program in NLPHL may be a critical mechanism limiting PLK1-dependent tumor growth.

Interim PET-guided treatment for early-stage NLPHL: a subgroup analysis of the randomized GHSG HD16 and HD17 studies

The optimal first-line treatment for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) diagnosed in early stages is largely undefined. We, therefore, analyzed 100 NLPHL patients treated in the randomized HD16 (early-stage favorable; n = 85) and HD17 (early-stage unfavorable; n = 15) studies. These studies investigated the omission of consolidation radiotherapy (RT) in patients with a negative interim positron emission tomography (iPET) (ie, Deauville score <3) after chemotherapy (HD16: 2× doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD]; HD17: 2× escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone [BEACOPP] plus 2× ABVD). Patients with NLPHL treated in the HD16 and HD17 studies had 5-year progression-free survival (PFS) rates of 90.3% and 92.9%, respectively. Thus, the 5-year PFS did not differ significantly from that of patients with classical Hodgkin lymphoma treated within the same studies (HD16: P = .88; HD17: P = .50). Patients with early-stage favorable NLPHL who had a negative iPET after 2× ABVD and did not undergo consolidation RT tended to have a worse 5-year PFS than patients with a negative iPET who received consolidation RT (83% vs 100%; P = .05). There were 10 cases of NLPHL recurrence. However, no NLPHL patient died during follow-up. Hence, the 5-year overall survival rate was 100%. Taken together, contemporary Hodgkin lymphoma-directed treatment approaches result in excellent outcomes for patients with newly diagnosed early-stage NLPHL and, thus, represent valid treatment options. In early-stage favorable NLPHL, consolidation RT appears necessary after 2× ABVD to achieve the optimal disease control irrespective of the iPET result.

Nodular lymphocyte-predominant Hodgkin lymphoma: current management strategies and evolving approaches to individualize treatment

INTRODUCTION

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity accounting for roughly 5% of all Hodgkin lymphoma (HL) cases. In contrast to classical HL, the malignant cells in NLPHL are positive for CD20 but lack CD30. The disease usually has an indolent clinical course resulting in high long-term survival rates.

AREAS COVERED

In this review, treatment options for NLPHL are summarized and factors that may help to individualize treatment are discussed.

EXPERT OPINION

Stage IA NLPHL without clinical risk factors should be treated with limited-field radiotherapy alone. In all other stages, NLPHL patients have excellent outcomes after standard HL approaches. The question of whether the addition of an anti-CD20 antibody to standard HL chemotherapy protocols or the use of approaches typically applied in B-cell non-Hodgkin lymphoma improve treatment results is unanswered until now. Different management strategies ranging from low-intensity treatment to high-dose chemotherapy and autologous stem cell transplantation have demonstrated activity in relapsed NLPHL. Second-line treatment is thus chosen individually. The major aim of NLPHL research is to spare toxicity and reduce the risk for treatment-related adverse events in low-risk patients while treating higher-risk patients with appropriate intensity. To this end, novel tools to guide treatment are required.

Treatment of Nodular Lymphocyte-Predominant Hodgkin Lymphoma: Where Do We Stand? Where Do We Go?

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare B cell-derived lymphoma entity accounting for ≈5% of all Hodgkin lymphoma (HL) cases. In recent decades, patients with newly diagnosed NLPHL have usually been treated very similarly to classical HL (cHL). The 10-year overall survival rates with HL-directed approaches are in excess of 90%. However, pathological and clinical characteristics of NLPHL resemble indolent B-cell non-Hodgkin lymphoma (B-NHL) in some aspects. Thus, nodular lymphocyte-predominant B-cell lymphoma has been proposed as an alternative name, and the use of B-NHL-directed treatment strategies has become more common in NLPHL despite limited data. Given the often indolent clinical course of NLPHL, even in the case of relapse, the majority of patients with disease recurrence do not require high-dose chemotherapy and autologous stem cell transplantation but are treated sufficiently with low-intensity approaches such as single-agent anti-CD20 antibody treatment. The establishment of novel prognostic scores for NLPHL patients may optimize risk group and treatment allocation in newly diagnosed and relapsed disease.

Role of Rituximab Addition to First-line Chemotherapy Regimens in Nodular Lymphocyte-predominant Hodgkin Lymphoma: A Study by Fondazione Italiana Linfomi

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare entity whose neoplastic cells retain a B-cell phenotype with expression of CD20. Radiotherapy is recommended for favorable stage IA disease while for other stages guidelines suggest therapeutic strategies similar to those used for classic HL. The role of rituximab, although quite widespread, is not completely elucidated. We retrospectively analyzed baseline characteristics of 308 consecutive patients with NLPHL diagnosed in 19 Italian centers from 2000 to 2018. With a median follow-up of 8.4 years (interquartile range: 4.5–12.4) for treated patients, median overall survival (OS) was not reached and estimated 5-year OS was 97.8% and 5-year progression-free survival (PFS) was 84.5%. Five-year cumulative incidence of histological transformation was 1.4%, 95% confidence interval (CI), 0.5%-3.8%. After adjusting for lymphocyte count, splenic involvement, bulky disease and B symptoms (fever, drenching night sweats, unintentional loss >10% of body weight within the preceding 6 months), patients with stage II or more showed superior PFS with immunochemotherapy in comparison to chemotherapy alone (hazard ratio = 0.4, 95% CI, 0.2-0.8; P = 0.015). Our data suggest an advantage of the use of rituximab combined with chemotherapy ± radiotherapy in the treatment of stage II–III–IV NLPHL.

Treatment patterns and outcomes in adolescents and young adults with nodular lymphocyte-predominant Hodgkin lymphoma: an IMPACT cohort study

We leveraged population-based clinical and healthcare data to identify treatment patterns and long-term outcomes among adolescents and young adults (AYA) with nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). All Ontario, Canada, AYA aged 15-21 years at diagnosis with NLPHL between 1992 and 2012 were identified, and their detailed clinical data were collected. Linkage to healthcare databases identified additional events (subsequent malignant neoplasms [SMN], relapses and deaths). Event-free survival (EFS) and overall survival (OS) were compared by locus of care (adult vs. paediatric) and predictors of outcomes determined. Of 1014 AYA with Hodgkin lymphoma, 54 (5.3%) had NLPHL; 15 (27.8%) were treated at a paediatric centre. No paediatric centre patient received radiation only versus 16 (41.0%) of adult centre patients. Excision only was more common in paediatric centres (p < 0.001). The 20-year EFS and OS rates were 82.9% ± 5.2% and 100% respectively. Advanced stage (hazard ratio: 4.9, 95% CI: 1.3-18.4; p = 0.02) was associated with inferior EFS. Although the 25-year cumulative incidence of SMN was 19.3% ± 9.6% for the entire cohort, there were no SMN among the patients treated with excision only. AYA with NLPHL have outstanding long-term survival. Resection alone was rare outside of paediatric institutions but associated with excellent outcomes. Given substantial SMN risks, chemotherapy-sparing and radiation-sparing strategies for appropriate subsets of patients are warranted.

Treatment approaches for nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare variant of Hodgkin lymphoma characterized by a persistent risk of relapse but an excellent overall survival. Historically, it was treated similarly to classic Hodgkin lymphoma, but efforts have been made to deintensify treatment due to risk of late toxicity associated with intensive therapy. For patients with completely resected stage IA NLPHL, no further treatment may be considered, particularly for pediatric patients. For those with stage I-II NLPHL without risk factors such as B symptoms, sites>2, or variant pattern histology, lower intensity treatment with radiotherapy or chemotherapy alone may be sufficient. However, combined modality therapy is a standard treatment for favorable and unfavorable risk stage I-II NLPHL associated with excellent progression-free and overall survival rates. For patients with advanced stage NLPHL, the optimal chemotherapy is not defined, but R-CHOP appears to be an effective treatment. Efforts to study NLPHL through multicenter collaborative efforts are crucial to develop evidence based and individualized treatments for patients with NLPHL.

Individualized patient care in nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma that has traditionally been considered a subgroup of Hodgkin lymphoma. However, morphology, surface marker expression, genetics, and clinical course are different from classic Hodgkin lymphoma. While most patients experience indolent disease with slow progression, some patients can also have more aggressive disease. Nevertheless, outcomes are excellent, and excess mortality due to NLPHL is at most very low. The treatment of newly diagnosed NLPHL has historically mirrored that of classic Hodgkin lymphoma. However, evidence for deviations from that approach has emerged over time and is discussed herein. Less evidence is available for the optimal management of relapsed patients. So-called variant histology has recently emerged as a biological risk factor, providing at least a partial explanation for the observed heterogeneity of NLPHL. Considering variant histology together with other risk factors and careful observation of the clinical course of the disease in each patient can help to assess individual disease aggressiveness. Also important in this mostly indolent disease are the preferences of the patient and host factors, such as individual susceptibility to specific treatment side effects. Considering all this together can guide individualized treatment recommendations, which are paramount in this rare disease.

Hodgkin Lymphoma: Biology and Differential Diagnostic Problem

Hodgkin lymphomas (HLs) are lymphoid neoplasms that are morphologically defined as being composed of dysplastic cells, namely, Hodgkin and Reed–Sternberg cells, in a reactive inflammatory background. The biological nature of HLs has long been unclear; however, our understanding of HL-related genetics and tumor microenvironment interactions is rapidly expanding. For example, cell surface overexpression of programmed cell death 1 ligand 1 (CD274/PD-L1) is now considered a defining feature of an HL subset, and targeting such immune checkpoint molecules is a promising therapeutic option. Still, HLs comprise multiple disease subtypes, and some HL features may overlap with its morphological mimics, posing challenging diagnostic and therapeutic problems. In this review, we summarize the recent advances in understanding the biology of HLs, and discuss approaches to differentiating HL and its mimics.

Management of children and adults with all stages of nodular lymphocyte predominant Hodgkin lymphoma - All StAGEs: A consensus-based position paper from the Hodgkin lymphoma subgroup of the UK National Cancer Research Institute

A consensus statement for the management for patients of all ages with all stages of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) - All StAGEs - is proposed by representatives of the UK National Cancer Research Institute (NCRI) Hodgkin lymphoma study group and the Children's Cancer & Leukaemia Group. Based on current practices and published evidence, a consensus has been reached regarding diagnosis, staging and risk-ik7 stratified management which includes active surveillance, low- and standard-dose immunochemotherapy and radiotherapy.

Nodular Lymphocyte-predominant Hodgkin Lymphoma With Nodular Sclerosis: An Underrecognized Feature Associated With Pattern D

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) with unusual features, including some that can overlap morphologically with classic Hodgkin lymphoma (CHL), have been described. Herein, we describe 12 cases of NLPHL with fibrous bands and capsular fibrosis resembling, in part, nodular sclerosis (NS) CHL. Seven of 12 cases harbored Reed-Sternberg-like cells, further suggestive of CHL, but all cases lacked associated eosinophils and/or plasma cells in the background. In this cohort, all cases had areas of so-called pattern D (nodular T-cell rich) as a sole component in 7 (58%) cases or as a hybrid pattern along with pattern E (diffuse T-cell/histiocyte-rich) in 5 (42%) cases. The immunophenotype of the large neoplastic cells in these cases supported their being lymphocyte predominant cells of NLPHL, positive for CD20, CD79a, and OCT2, and negative for CD15 and CD30. However, PAX5 was weak in 9 of 11 cases similar to Hodgkin/Reed-Sternberg cells in CHL. We conclude that some cases of NLPHL are associated with fibrous bands and capsular fibrosis and resemble, in part, NS CHL. In our experience, NLPHL with NS-like features occurs in 10% to 15% of cases of NLPHL and is associated with a variant pattern (D and/or E). In addition, all patients in this cohort were not treated before biopsy, suggesting that the prominent sclerosis in these cases is inherent to disease biology. Recognition of NLPHL with NS-like features further expands the morphologic spectrum of NLPHL and helps avoid potential misdiagnosis as CHL.

Nodular Lymphocyte-Predominant Hodgkin Lymphoma: Review of Current Literature and Case Discussion

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare subset of Hodgkin lymphoma (HL). It has a distinct clinical and pathological presentation. Unlike classic HL, where the predominant malignant cells are Reed Sternberg cells, the malignant cells in NLPHL are known as lymphocyte predominant (LP) cells, with their own unique immunohistochemistry antigen expression and staining pattern. Based on risk stratification and staging of the disease, treatment can range from active surveillance in asymptomatic patients with no organ compromise or bulky disease, to aggressive chemotherapeutic agents in advanced disease. Guidelines on which of these chemotherapy regimens would offer the most benefit to our patients are limited due to lack of randomized-controlled studies. Majority of the current prospective data on treatment were inclusive of both HL and NLPHL. Thus, the regimens employed in treatment of NLPHL are similar to the ones used in HL, though NLPHL is often viewed as its own distinct entity. This article aims to review the current literature and future advances on treatment of this rare disease.

Outcome of limited-stage nodular lymphocyte-predominant Hodgkin lymphoma and the impact of a PET-adapted approach

Radiotherapy (RT) is typically incorporated into the treatment of limited-stage nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), although it remains unknown whether chemotherapy alone may be suitable in select patients. We evaluated outcomes of limited-stage NLPHL at BC Cancer on the basis of era-specific guidelines: routine RT era, 1995 to 2005 (n = 36), combined modality with 2 cycles of doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) chemotherapy followed by RT or RT alone; positron emission tomography (PET) era, after 2005 (n = 63), ABVD alone (4 cycles) if the PET scan after the second cycle of ABVD (PET2) is negative, or treatment is changed to RT if PET2 is positive. Median age of patients was 38 years (range, 16-82 years), 73% were male, and 43% had stage II. With a median follow-up of 10.5 years for all patients, 5-year progression-free survival (PFS) was 91% [corrected] and was 97% for overall survival (OS), with no difference by treatment era (PFS, P = .15; [corrected] OS, P = .35). For the 49 patients who had a PET2 scan, 86% were PET negative and 14% were PET positive by Deauville criteria with 5-year PFS rates of 92% and 80% (P = .87) [corrected], respectively. This is the largest study of a PET-adapted approach in NLPHL and supports that ABVD alone may be a viable option in select patients with a negative PET2 scan, with consideration of acute and long-term toxicities.

Current treatment options for nodular lymphocyte-predominant Hodgkin lymphoma

PURPOSE OF REVIEW

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare B cell-derived malignancy. This review aims at providing an overview of recent developments in the management of NLPHL.

RECENT FINDINGS

Patients with stage IA NLPHL without risk factors have excellent outcomes. The 8-year progression-free survival (PFS) is roughly 90% and the 8-year overall survival (OS) close to 100% after limited-field radiotherapy (RT) alone. Individuals presenting with early stages other than stage IA without risk factors and intermediate stages have 10-year PFS rates in excess of 70% and 10-year OS rates exceeding 90% when treated with 2 and 4 cycles of ABVD, respectively, followed by consolidation RT. In advanced NLPHL, different protocols such as BEACOPP, ABVD, and R-CHOP have been evaluated retrospectively. However, the optimal approach is undefined. Patients with relapsed NLPHL mostly receive single-agent anti-CD20 antibody treatment or conventional chemotherapy. High-dose chemotherapy and autologous stem cell transplantation are restricted to high-risk patients. NLPHL recurrence is salvaged successfully in the majority of cases.

SUMMARY

Patients with NLPHL have a very good prognosis. Treatment differs from classical Hodgkin lymphoma in some situations.

Outcome of relapsed and refractory nodular lymphocyte-predominant Hodgkin lymphoma: a North American analysis

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare entity, with limited data on the outcome in the relapsed/refractory setting. We evaluated the outcome of all patients diagnosed between 04/1979 and 01/2019 with relapsed or progressive NLPHL after initial active therapy at two institutions, refractory disease being defined as lack of response to treatment and/or relapse within three months of treatment. NLPHL patients with histological evidence of transformation at time of first relapse or progression were excluded. In total, 69 patients with recurrent NLPHL were included in the study. After a median follow-up after initial diagnosis of 14 years (range, 0·5-46 years), median progression-free survival after front-line treatment (PFS-1) was four years. Second-line therapy included chemotherapy in 28 (41%) patients, biological therapy (rituximab, lenalidomide or brentuximab vedotin) in 14 (20%), high-dose chemotherapy followed by autologous stem cell transplant in 14 (20%) and radiation therapy (RT) alone in 10 (15%). The five-year PFS after second-line therapy (PFS-2) was 68% [95% confidence interval (CI), 54-79%] but the five-year overall survival (OS) after second-line therapy (OS-2) remained excellent, at 94% (95% CI, 85-99%). Due to excellent outcome in case of recurrence, studies aimed at characterizing its biology to guide therapy de-escalation are needed.

Pitfalls in the Diagnosis of Nodular Lymphocyte Predominant Hodgkin Lymphoma: Variant Patterns, Borderlines and Mimics

Simple Summary

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma containing infrequent tumor cells (LP cells) in a background of non-neoplastic cells. Some cases of NLPHL can recur or progress to a more aggressive lymphoma, such as diffuse large B-cell lymphoma. Awareness of the different appearances of NLPHL and its overlap with other lymphomas are important for the appropriate diagnosis, classification and research. This article discusses the conceptual framework and guidelines for the diagnosis of NLPHL, and how NLPHL can be best separated from its mimics. Emerging data in the field point to genetic changes in LP cells that are shaped by immune mechanisms. In addition, non-neoplastic cells in the background of LP cells also appear to play an important role. Further investigation is necessary to fully understand the biology of NLPHL and personalize cancer care for patients affected by this lymphoma.

Abstract

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) represents approximately 5% of Hodgkin lymphoma and typically affects children and young adults. Although the overall prognosis is favorable, variant growth patterns in NLPHL correlate with disease recurrence and progression to T-cell/histiocyte-rich large B-cell lymphoma or frank diffuse large B-cell lymphoma (DLBCL). The diagnostic boundary between NLPHL and DLBCL can be difficult to discern, especially in the presence of variant histologies. Both diagnoses are established using morphology and immunophenotype and share similarities, including the infrequent large tumor B-cells and the lymphocyte and histiocyte-rich microenvironment. NLPHL also shows overlap with other lymphomas, particularly, classic Hodgkin lymphoma and T-cell lymphomas. Similarly, there is overlap with non-neoplastic conditions, such as the progressive transformation of germinal centers. Given the significant clinical differences among these entities, it is imperative that NLPHL and its variants are carefully separated from other lymphomas and their mimics. In this article, the characteristic features of NLPHL and its diagnostic boundaries and pitfalls are discussed. The current understanding of genetic features and immune microenvironment will be addressed, such that a framework to better understand biological behavior and customize patient care is provided.

Rituximab-Containing Risk-Adapted Treatment Strategy in Nodular Lymphocyte Predominant Hodgkin Lymphoma: 7-Years Follow-Up

BACKGROUND

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare variant of HL that accounts for 5% of all HL cases. The expression of CD20 on neoplastic lymphocytes provides a suitable target for novel treatments based on Rituximab. Due to its rarity, consolidated and widely accepted treatment guidelines are still lacking for this disease.

METHODS

Between 1 December 2007 and 28 February 2018, sixteen consecutive newly diagnosed adult patients with NLPHL received Rituximab (induction ± maintenance)-based therapy, according to the baseline risk of German Hodgkin Study Group prognostic score system. The treatment efficacy and safety of the Rituximab-group were compared to those of a historical cohort of 12 patients with NLPHL who received Doxorubicin, Bleomycin, Vinblastine, Dacarbazine (ABVD) chemotherapy followed by radiotherapy (RT), if needed, according to a similar baseline risk. The primary outcome was progression-free survival (PFS) and secondary outcomes were overall survival (OS) and side-effects (according to the Common Terminology Criteria for Adverse Events, v4.03).

RESULTS

After a 7-year follow-up (range, 1-11 years), PFS was 100% for patients treated with the Rituximab-containing regimen versus 66% for patients of the historical cohort (p = 0.036). Four patients in the latter group showed insufficient response to therapy. The PFS for early favorable and early unfavorable NLPHLs was similar between treatment groups, while a better PFS was recorded for advanced-stages treated with the Rituximab-containing regimen. The OS was similar for the two treatment groups. Short- and long-term side-effects were more frequently observed in the historical cohort. Grade ≥3 neutropenia was more frequent in the historical cohort compared with the Rituximab-group (58.3% vs. 18.7%, respectively; p = 0.03). Long-term non-hematological toxicities were observed more frequently in the historical cohort.

CONCLUSION

Our results confirm the value of Rituximab in NLPHL therapy and show that Rituximab (single-agent) induction and maintenance in a limited-stage, or Rituximab with ABVD only in the presence of risk factors, give excellent results while sparing cytotoxic agent- and/or RT-related damage. Furthermore, Rituximab inclusion in advanced-stage therapeutic strategy seems to improve PFS compared to conventional chemo-radiotherapy.

Nodular lymphocyte-predominant Hodgkin lymphoma characteristics, management of primary and relapsed/refractory disease and outcome analysis: the first comprehensive report from the Middle East

BACKGROUND

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon variant of Hodgkin lymphoma. There is limited data on treatment, management of refractory and relapsed disease, and long-term outcome. Many registries or country-wide data reports are unable to provide detailed primary and subsequent management. We are reporting our observation on patient's characteristics, management, and outcome.

METHODS

This single-institution retrospective cohort analysis includes NLPHL patients seen from 1998 to July 2019. We used Fisher's exact test, chi-square, and Kaplan-Meier (KM) method for various analyses.

RESULTS

Two hundred patients were identified, (6.34% of all the HL). Male:female was 3:1. The median age at diagnosis was 22 years (4-79 years). Stage I-II in 145 (72.5%) cases. One hundred patients (50%) received chemotherapy, 68 (34%) chemotherapy + radiation therapy (RT); 87% of all chemotherapy was ABVD (adriamycin, bleomycin, vinblastine, dacarbazine). Thirteen patients (6.5%) received RT alone and 16 (8%) had surgery alone. Complete response in 82%, partial response in 5.5% and progressive disease in 10.5%. The median follow is 60 months (5-246). Median 5 and 10 years overall survival (OS) is 94.8 and 92.4% (stages I-II, 97.7 and 97.7%, stage III-IV, 94.8 and 92.4%). Median event-free survival (EFS) is 62.3 and 54% respectively (stage I-II, 72 and 64%, stage III-IV, 36.4 and 18.2%). Stage I-II vs III-IV OS (p = < 0.001) and EFS (p = < 0.001) were significant. For stage I-II, 5 year EFS of chemotherapy + RT (83.3%) was superior to chemotherapy alone (60%, p = 0.008). Five year EFS for early favorable (80%), early unfavorable (60%), and advanced (36.4%) was significant (p = < 0.001). Eleven patients (5.5%) had high-grade transformation. Twenty-nine patients underwent HDC auto-SCT, all are alive (28 in remission). 25% of patients had pathologically proved nodal hyperplasia at some point in time.

CONCLUSION

OS of NLPHL is excellent and independent of treatment type. EFS is better for chemotherapy + RT than chemotherapy alone. Stem cell transplant in refractory / multiple relapses resulted in excellent disease control. There is a need to identify optimal treatment strategies accordingly to the risk stratification.

Hodgkin Lymphoma-Review on Pathogenesis, Diagnosis, Current and Future Treatment Approaches for Adult Patients

Hodgkin lymphoma (HL) is a rare malignancy accounting for roughly 15% of all lymphomas and mostly affecting young patients. A second peak is seen in patients above 60 years of age. The history of HL treatment represents a remarkable success story in which HL has turned from an incurable disease to a neoplasm with an excellent prognosis. First-line treatment with stage-adapted treatment consisting of chemotherapy and/or radiotherapy results in cure rates of approximately 80%. Second-line treatment mostly consists of intensive salvage chemotherapy followed by high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). Novel approaches such as antibody drug conjugates and immunomodulatory drugs have shown impressive results in clinical trials in refractory and relapsed HL and are now increasingly implemented in earlier treatment lines. This review gives a comprehensive overview on HL addressing epidemiology, pathophysiology and current treatment options as well as recent developments and perspectives.

Stage I-II nodular lymphocyte-predominant Hodgkin lymphoma: a multi-institutional study of adult patients by ILROG

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon histologic variant, and the optimal treatment of stage I-II NLPHL is undefined. We conducted a multicenter retrospective study including patients ≥16 years of age with stage I-II NLPHL diagnosed from 1995 through 2018 who underwent all forms of management, including radiotherapy (RT), combined modality therapy (CMT; RT+chemotherapy [CT]), CT, observation after excision, rituximab and RT, and single-agent rituximab. End points were progression-free survival (PFS), freedom from transformation, and overall survival (OS) without statistical comparison between management groups. We identified 559 patients with median age of 39 years: 72.3% were men, and 54.9% had stage I disease. Median follow-up was 5.5 years (interquartile range, 3.1-10.1). Five-year PFS and OS in the entire cohort were 87.1% and 98.3%, respectively. Primary management was RT alone (n = 257; 46.0%), CMT (n = 184; 32.9%), CT alone (n = 47; 8.4%), observation (n = 37; 6.6%), rituximab and RT (n = 19; 3.4%), and rituximab alone (n = 15; 2.7%). The 5-year PFS rates were 91.1% after RT, 90.5% after CMT, 77.8% after CT, 73.5% after observation, 80.8% after rituximab and RT, and 38.5% after rituximab alone. In the RT cohort, but not the CMT cohort, variant immunoarchitectural pattern and number of sites >2 were associated with worse PFS (P < .05). Overall, 21 patients (3.8%) developed large-cell transformation, with a significantly higher transformation rate in those with variant immunoarchitectural pattern (P = .049) and number of involved sites >2 (P = .0006). OS for patients with stage I-II NLPHL was excellent after all treatments.

Long-term follow-up of patients with nodular lymphocyte predominant Hodgkin lymphoma: A report from the Spanish Lymphoma Oncology Group

Nodular lymphocytic predominance Hodgkin lymphoma (NLPHL) is a very uncommon subtype of Hodgkin lymphoma (HL), representing approximately 5% of all HL cases, with an incidence of 0.3/100,000 cases per year and with unique characteristics which distinguish it from classic Hodgkin lymphoma. Given its low frequency, there is a lack of prospective randomized studies to inform practice, the accumulated experience of academic groups being the main source of relevant information for the management of these patients. Eighty-five patients recruited by the Spanish Lymphoma Group (GOTEL) from 12 different hospitals were retrospectively analyzed to describe their sociodemographic and clinical characteristics. The median follow-up was 16 years, with a 10-year overall survive of 92.9% and 81.2% at 20 years. Five patients developed a second malignancy. No transformation to a more aggressive lymphoma was detected. A total of 31% tumor relapses was found: 77% in a single location; most of them at a supra-diaphragmatic level. Patients received different first-line treatments, and progression was observed in 3/4 (75%) of the patients who did not receive any type of treatment, 6/23 (26%) who received both chemotherapy (CH) and radiotherapy (RT), 12/43 (27%) who received RT and 7/15 (47%) that received only CH treatment. The mean time to relapse was 3 years and 47% presented relapses beyond 5 years (higher probability in stage IV p < 0.001). This is one of the longest follow-up series of NLPHL published, confirming its excellent prognosis, and that treatments may be adapted to reduce toxicity. Causes of death in these patients are varied, and the minority due to a primary malignancy relapses.

How we treat mature B-cell neoplasms (indolent B-cell lymphomas)

Mature B cell neoplasms, previously indolent non-Hodgkin lymphomas (iNHLs), are a heterogeneous group of malignancies sharing similar disease courses and treatment paradigms. Most patients with iNHL have an excellent prognosis, and in many, treatment can be deferred for years. However, some patients will have an accelerated course and may experience transformation into aggressive lymphomas. In this review, we focus on management concepts shared across iNHLs, as well as histology-specific strategies. We address open questions in the field, including the influence of genomics and molecular pathway alterations on treatment decisions. In addition, we review the management of uncommon clinical entities including nodular lymphocyte-predominant Hodgkin lymphoma, hairy cell leukemia, splenic lymphoma and primary lymphoma of extranodal sites. Finally, we include a perspective on novel targeted therapies, antibodies, antibody-drug conjugates, bispecific T cell engagers and chimeric antigen receptor T cell therapy.

The stage-specific roles of radiotherapy and chemotherapy in nodular lymphocyte predominant Hodgkin lymphoma patients: a propensity score-matched analysis of the SEER database

BACKGROUND

The stage-specific roles of radiotherapy (RT) alone, chemotherapy alone, and combined RT and chemotherapy (CRT) for patients with nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) have not been adequately evaluated.

METHODS

We analyzed patients with all stages of NLPHL enrolled in the Surveillance, Epidemiology, and End Results (SEER) registry from January 2000 to December 2015. Propensity score (PS) analysis with 1:1 matching (PSM) was performed to ensure the well-balanced characteristics of the comparison groups. Kaplan-Meier and Cox proportional-hazards models were used to evaluate the overall survival (OS), cancer-specific survival (CSS), hazard ratios (HRs), and corresponding 95% confidence intervals (95% CI). Restricted mean survival times (RMST) were also used for the survival analyses.

RESULTS

For early-stage patients, CRT was associated with the best survival, the mean OS was significantly improved by approximately 20 months (20 m), and the risk of death was reduced by more than 80%, both before and after PSM (p < 0.05). For advanced-stage patients, none of RT alone, chemotherapy alone, or CRT had a significant effect on survival. Chemotherapy alone and CRT might be more beneficial for long-term survival (RMST120 m : neither RT nor chemotherapy vs. chemotherapy alone vs. CRT = 104 m vs. 111 m vs. 108 m). Subgroup analysis of patients with early-stage NLPHL showed that CRT was associated with better survival of elderly patients (improved OS = 43.8 m, HR = 0.14, p < 0.05). However, the survival benefits of treatments for young patients were not statistically significant. The efficacy of RT was significantly different between the age groups (pfor interaction  = 0.020).

CONCLUSIONS

These results from SEER data suggest that CRT may be considered for early-stage NLPHL, especially for elderly patients. Further studies are needed to identify effective treatments in patients with advanced-stage NLPHL.

How I treat nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity with distinct pathologic and clinical characteristics. Unlike the malignant cells in classical Hodgkin lymphoma, the disease-defining lymphocyte-predominant cells in NLPHL are consistently positive for CD20, but do not express CD30. The clinical course of NLPHL is indolent in the majority of cases. Most patients present with early-stage disease at the initial diagnosis. First-line treatment of stage IA NLPHL usually consists of limited-field radiotherapy alone. Patients with early-stage NLPHL other than stage IA and intermediate-stage disease mostly receive combined-modality treatment, whereas individuals with advanced NLPHL are treated with chemotherapy alone. In relapsed NLPHL, conventional chemotherapy, anti-CD20 antibodies, and radiotherapy represent active treatment modalities. Only patients with poor-risk characteristics such as early disease recurrence are candidates for aggressive salvage treatment with high-dose chemotherapy and autologous stem cell transplantation. The overall and relative survival of patients with NLPHL is excellent as indicated by a low excess mortality compared with the general population. This article discusses treatment options for patients with NLPHL and factors that influence the choice of therapy on the basis of the available data and 2 clinical cases.

Favorable outcomes with de-escalated radiation therapy for limited-stage nodular lymphocyte-predominant Hodgkin lymphoma

Radiation fields for limited-stage nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) have shrunk over time; involved-site radiation therapy (ISRT) has replaced extended-field radiation therapy (EFRT) and involved-field radiation therapy (IFRT), but this has not been validated. The role of systemic therapy is unclear. We reviewed 71 stage I/II NLPHL patients and assessed progression-free survival (PFS), overall survival (OS), locoregional disease-free survival, and distant disease-free survival (DDFS). Median patient age was 39 years, and 61% had stage II disease. Thirty-six (51%) received radiation therapy (RT) only, 6 (8%) received systemic therapy only, and 29 (41%) received both. More patients receiving combined therapy had B symptoms (P = .035) and stage II disease (P = .001). In the RT-only group, 9 (25%) received EFRT, 13 (36%) received IFRT, and 14 (39%) received ISRT; in the combined-modality group, 3 (10%) received EFRT, 7 (24%) received IFRT, and 19 (66%) received ISRT. After a median follow-up of 6.2 years, 15 patients relapsed (13 distant, 2 locoregional). Five-year PFS and OS rates were 86% and 96% and did not differ by treatment. In the RT-only group, follow-up was shorter in the ISRT cohort (2.6 years vs 17.9 years [EFRT] and 8.5 years [IFRT], P < .01), but 5-year PFS did not differ by field size (P = .20). Locoregional control rates were 100% for the RT-only and combined groups, and corresponding 5-year DDFS rates were 93% and 95% (P = .95). Eight patients (11%) experienced a second malignancy (1 within RT field). Six patients died (1 from lymphoma). Use of limited ISRT fields does not appear to increase the risk of locoregional relapse, even when RT is given as single-modality therapy.

Long-Term Follow-Up of Patients With Nodular Lymphocyte-Predominant Hodgkin Lymphoma Treated in the HD7 to HD15 Trials: A Report From the German Hodgkin Study Group

PURPOSE

The optimal treatment of newly diagnosed nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is ill defined. We therefore conducted a retrospective analysis using the database of the German Hodgkin Study Group (GHSG).

PATIENTS AND METHODS

The long-term course of 471 patients with NLPHL (early stages, n = 251; intermediate stages, n = 76; advanced stages, n = 144) who had received stage-adapted first-line treatment in the randomized GHSG HD7 to HD15 studies was investigated. Treatment consisted of radiotherapy alone, chemotherapy alone, or combined-modality approaches.

RESULTS

The median age at NLPHL diagnosis was 39 years (range, 16 to 75 years). Patients were mostly male (75.8%). The median observation time was 9.2 years. At 10 years, progression-free survival and overall survival estimates were 75.5% and 92.1% (early stages, 79.7% and 93.3%; intermediate stages, 72.1% and 96.2%; advanced stages, 69.8% and 87.4%), respectively. A total of 48 patients (10.2%) developed a second malignancy during follow-up (non-Hodgkin lymphoma, n = 13; leukemia, n = 6; solid tumor, n = 25; unspecified malignancy, n = 4). Death occurred in 43 patients (9.1%). However, only a minority of deaths were NLPHL related (n = 10), whereas second malignancies (n = 20) and nonmalignant conditions possibly associated with radiotherapy or chemotherapy (n = 13) caused the death in the majority of patients.

CONCLUSION

The overall outcome of patients with NLPHL who had received Hodgkin lymphoma–directed first-line treatment in randomized GHSG trial protocols was good. Nonetheless, treatment optimization is still necessary to reduce toxicity in standard-risk patients and to improve the prognosis in high-risk patients.

Treatment of Nodular Lymphocyte Hodgkin Lymphoma: The Goldilocks Principle

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Active surveillance for nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare subtype of lymphoma that, like other Hodgkin lymphomas, has historically been treated aggressively. However, in most cases, NLPHL has an indolent course, which raises the question of to what extent these patients require aggressive upfront treatment. We describe the management and outcomes of consecutive NLPHL patients diagnosed at Memorial Sloan Kettering Cancer Center (MSK), with a focus on evaluating active surveillance. All patients aged 16 years or older diagnosed and followed at MSK between 1974 and 2016 were included. Treatment outcomes were compared between management with active surveillance and other strategies. We identified 163 consecutive patients who were treated with radiotherapy alone (46%), active surveillance (23%), chemotherapy (16%), combined modality (12%), or rituximab monotherapy (4%). Median follow-up was 69 months. Five-year progression-free survival (PFS), second PFS (PFS2), and overall survival (OS) estimates were 85% (95% confidence interval [CI], 78-90), 97% (95% CI, 92-99), and 99% (95% CI, 95-100), respectively. Only 1 of 7 deaths was lymphoma related. Patients managed with active surveillance had slightly shorter PFS than those receiving any active treatment, with 5-year PFS of 77% (95% CI, 56-89) vs 87% (95% CI, 79-92; P = .017). This difference did not translate into better PFS2 or OS. Only 10 patients managed with active surveillance (27%) eventually required treatment, after a median of 61 months, and none died. NLPHL has an excellent prognosis. Within the limitations of a retrospective analysis, active surveillance is a viable initial management strategy for selected NLPHL patients.

Use of flow cytometry in the phenotypic diagnosis of hodgkin's lymphoma

Hodgkin's lymphoma (HL) has a unique immunophenotype derived from immunohistochemistry (positive for CD15, CD30, and Pax-5; negative for CD3, CD20 in most cases, and CD45). The knowledge gained over recent years enables better diagnosis, prognosis, and treatment of HL. Flow cytometry as a tool for the diagnosis of classic HL has not been useful in the past due to the difficulty in isolating Reed-Sternberg cells as they are admixed in a rich inflammatory background which consists mainly of T cells, B cells, eosinophils, histiocytes, and plasma cells. However, in the recent past, several studies have tried to identify Reed-Sternberg cells using flow cytometry on fine needle aspiration or tissue biopsy of lymph nodes to confirm or supplement immunohistochemistry staining in diagnosis. Newer and more sensitive tools such as flow cytometry can be used for diagnosis, technology that may have been difficult in the past for diagnosis of this lymphoma subtype. Using flow cytometry, diagnosis is faster and could lead to point-of-care technology especially where we have typical immunophenotype signatures. © 2018 International Clinical Cytometry Society.

Eichenauer* D, Jakob T, Follmann M, Engert A, Skoetz N. Hodgkin Lymphoma in Adults

BACKGROUND

Hodgkin lymphoma is the most common neoplasm in young adults, with an incidence of 2 to 3 cases per 100 000 persons per year. Risk-adapted chemotherapy and radiotherapy usually lead to cure. Finding ways to lessen the treatment- associated morbidity and mortality is a major goal of current research.

METHODS

For the creation of an updated guideline (DKH grant number 111778), a systematic literature search was carried out in medical databases (MEDLINE, CENTRAL) and guideline databases (GIN) (search dates: January 2012 to June 2017).

RESULTS

Results from 10 meta-analyses, 89 randomized and controlled trials, and 81 prospective or retrospective trials were evaluated. The use of positron emission tomography (PET) is strongly recommended in the initial diagnostic evaluation, as well as for the guidance of treatment in advanced stages. In early stages, two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and involved-site radiotherapy (IS-RT) at a dose of 20 Gy are recommended. For the treatment of intermedi- ate stages, two cycles of escalated BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) + two cycles of ABVD and 30 Gy IS-RT are recommended. In advanced stages, two cycles of escalated BEACOPP are administered, and then PET is performed for the guidance of further treatment: two further cycles of escalated BEACOPP are recommended if the PET is negative and four further cycles if it is positive, followed by radiotherapy of PET- positive residual tumor tissue. The five-year survival of patients with Hodgkin lymphoma is 95%. In case of disease recurrence, high-dose chemotherapy followed by autologous stem-cell transplantation is performed, and targeted drugs including brentuxi- mab vedotin, nivolumab, and pembrolizuab are used.

CONCLUSION

The highly favorable long-term prognosis of HL necessitates careful consideration of the intensity of treatment as well as thorough follow-up to enable the detection of late sequelae, such as second tumors or organ damage.

Relapsed and refractory nodular lymphocyte-predominant Hodgkin lymphoma: an analysis from the German Hodgkin Study Group

The optimal treatment of patients with relapsed or refractory nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is ill defined. To shed more light on treatment options and outcome, we performed an analysis using the database of the German Hodgkin Study Group (GHSG). Ninety-nine patients who had received first-line treatment within 12 prospective GHSG studies conducted between 1993 and 2009, and subsequently developed disease recurrence (n = 91) or had primary disease progression (n = 8), were included. At initial NLPHL diagnosis, the median age was 40 years and 76% of patients were male. First-line treatment consisted of radiotherapy (RT) alone (20%), chemotherapy with or without RT (74%), and the anti-CD20 antibody (Ab) rituximab (6%), respectively. The median follow-up from initial diagnosis was 11.2 years. The median time to disease recurrence was 3.7 years. The applied salvage approaches included single-agent anti-CD20 Ab treatment or RT alone (37%), conventional chemotherapy (CT) with or without anti-CD20 Ab treatment with or without RT (27%) and high-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) (31%). No salvage treatment was given in 4% of patients. The 5-year progression-free survival and overall survival estimates after NLPHL recurrence were 75.6% and 89.5% (74.1% and 97.2% after single-agent anti-CD20 Ab treatment or RT alone; 68.0% and 77.8% after CT with or without anti-CD20 Ab treatment with or without RT; 84.6% and 89.8% after HDCT and ASCT). Hence, patients with relapsed or refractory NLPHL had a good overall prognosis. Factors such as time to disease recurrence and previous treatment may guide the choice of the optimal salvage approach for the individual patient.

Adult nodular lymphocyte-predominant Hodgkin lymphoma: treatment modality utilization and survival

Early-stage nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is associated with a favorable prognosis. Our aim was to evaluate the patterns of care of radiotherapy utilization in this disease and to define the relationship between treatment modality and survival. The National Cancer Database was queried for patients with stages I-II NLPHL diagnosed from 2004 to 2012. Patients were compared based on primary therapy into four categories: radiotherapy, chemotherapy, both, or neither. Covariate-adjusted and propensity score-weighted (PS) Cox proportional hazards models were used, adjusting for potential factors confounding survival. After exclusions, 1420 patients were evaluated, 571 (40%) received radiotherapy alone, 318 (22%) received chemotherapy alone, 351 (25%) received both, and 180 (13%) received neither. Younger patient age (P = 0.001), female gender (P = 0.019), and chemotherapy use (P < 0.001) were associated with decreased radiotherapy utilization. On PS, radiation alone (HR = 0.298, P < 0.001) and chemoradiotherapy (HR = 0.258, P < 0.001) were associated with improved survival compared to no upfront therapy, but the use of chemotherapy alone did not statistically differ compared to no initial therapy (HR = 0.784, P = 0.078). In this large database analysis, over one-third of patients with early-stage NLPHL did not receive radiotherapy as a component of initial therapy. The omission of upfront radiotherapy was associated with inferior survival.

Nodular Lymphocyte-predominant Hodgkin Lymphoma in a 15-Year-Old Boy With Li-Fraumeni Syndrome Having a Germline TP53 D49H Mutation

Germline mutations in TP53 are the primary cause of Li-Fraumeni syndrome (LFS). Most mutations are reported within the DNA-binding domain. We report a case of a 15-year-old boy with LFS who developed early-stage nodular lymphocyte-predominant Hodgkin lymphoma, a rare subtype of Hodgkin lymphomas. His sister was diagnosed with embryonal rhabdomyosarcoma at the age of 1.5 years. Sequence analysis revealed a germline mutation in the transactivation domain of TP53, c.145G>C (p.D49H), in the patient, his sister, and father. One family with LFS with a germline TP53 D49H mutation has previously been reported. This report supports the pathogenicity of this mutation.

Hodgkin lymphoma: A review and update on recent progress

Hodgkin lymphoma (HL) is a unique hematopoietic neoplasm characterized by cancerous Reed-Sternberg cells in an inflammatory background. Patients are commonly diagnosed with HL in their 20s and 30s, and they present with supradiaphragmatic lymphadenopathy, often with systemic B symptoms. Even in advanced-stage disease, HL is highly curable with combination chemotherapy, radiation, or combined-modality treatment. Although the same doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapeutic regimen has been the mainstay of therapy over the last 30 years, risk-adapted approaches have helped de-escalate therapy in low-risk patients while intensifying treatment for higher risk patients. Even patients who are not cured with initial therapy can often be salvaged with alternate chemotherapy combinations, the novel antibody-drug conjugate brentuximab, or high-dose autologous or allogeneic hematopoietic stem cell transplantation. The programmed death-1 inhibitors nivolumab and pembrolizumab have both demonstrated high response rates and durable remissions in patients with relapsed/refractory HL. Alternate donor sources and reduced-intensity conditioning have made allogeneic hematopoietic stem cell transplantation a viable option for more patients. Future research will look to integrate novel strategies into earlier lines of therapy to improve the HL cure rate and minimize long-term treatment toxicities. CA Cancer J Clin 2018;68:116-132. © 2017 American Cancer Society.