Pediatric Classical Hodgkin Lymphoma Research Articles

Outcome and toxicity of ifosfamide, carboplatin, and etoposide versus gemcitabine and vinorelbine regimen for pediatric patients with relapsed or refractory Hodgkin's lymphoma.

Pediatric classical Hodgkin lymphoma (CHL) is a curable disease; however, the optimal salvage regimen is unclear for relapsed/refractory (R/R) disease. This study aimed to compare response rates, toxicity, event-free survival (EFS), and overall survival (OS) of ifosfamide, carboplatin, and etoposide (ICE) with gemcitabine and vinorelbine (GV) regimen after first-line doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) in pediatric patients with R/R CHL. This is a retrospective cohort study of 132 pediatric patients with R/R CHL treated from July 2012 to December 2020 with ICE (n = 82) or GV (n = 50). The median age at relapse was 13.9 years, and 68.2% were men. Rates of complete response, partial response, and progressive disease before consolidation were 50.6%, 3.7%, and 45.7% for ICE and 28.5%, 0%, and 71.5% for GV (P = 0.011). By multivariate analysis, regimen (P = 0.002), time to relapse (P = 0.0001), and B-symptoms (P = 0.002) were independent factors to lower response rates. Hematological toxicity, electrolyte disturbance, hemorrhagic cystitis, infectious complications, and hospital admission for fever neutropenia were statistically significant higher for the ICE regimen. Treatment-related mortalities were 2.4% for ICE and 2% for GV (P = 0.86). The 3-year EFS was 39.3% ± 11.4% for ICE and 24.9% ± 12.5% for GV (P = 0.0001), while 3-year OS was 69.3% ± 10.6% and 74% ± 12.9% (P = 0.3), respectively. By multivariate analysis, regimen (P = 0.0001), time to relapse (P = 0.011), B-symptoms (P = 0.001), and leukocytosis (P = 0.007) were significant for EFS, while anemia (P = 0.008), and progressive disease on early response evaluation (P = 0.022) were significant for OS. The ICE regimen had a better overall response rate and EFS, but higher toxicity, than GV; however, OS and mortality were similar.

An update on molecular features and therapeutic perspectives of pediatric classical Hodgkin Lymphoma. What the clinician needs to know?

Our understanding of Hodgkin lymphoma (HL) molecular biology has been radically transformed over recent years due to the advent and the spreading of the new generation sequencing approaches. These advances offer new insights about genetic predisposition to HL in children and are currently being translated into promising and more selective drugs (brentuximab and checkpoint inhibitors) offering the perspective to reduce treatment-related toxicity. Thus, as more than 90% of pediatric patients are cured after the first line treatment, a major emphasis is placed on survivorship by reducing treatment intensity, in particular, the use of radiotherapy and chemotherapy associated with long-term toxicities. The purposes of this review are to summarize the recent advances performed in the field of molecular biology of HL, in particular the promising development of liquid biopsies. We also provide an update review of immunodeficiencies associated to HL in children recently identified. Finally, we report the recent studies supporting the efficacy of new targeted therapeutics in adult and pediatric cHL (anti-CD30 and anti-PD1).

Pediatric classical Hodgkin lymphoma.

Over the past century, classical Hodgkin lymphoma (HL) has been transformed from a uniformly fatal disease to one of the most curable cancers. Given the high cure rate, a major focus of classical HL management is reducing the use of radiation therapy (RT) and chemotherapy agents such as procarbazine and doxorubicin to minimize long-term toxicities. In both North America and Europe, an important philosophy in the management of classical HL is to guide the intensity of treatment according to the risk category of the disease. The main factors used for risk classification are tumor stage, bulk of disease, and the presence of B symptoms. Response to chemotherapy is an important factor guiding the utilization of RT in ongoing Children's Oncology Group (COG) and European Network Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials. Both trial groups have transitioned to reduced RT volumes that target the highest risk sites using highly conformal techniques, along with standard or intensified chemotherapy regimens to improve outcomes in higher risk patients. However, given the potential acute toxicities of intensified chemotherapy, immunoregulatory drugs are being investigated in upcoming trials. The purpose of this review is to summarize current approaches to treating pediatric classical HL according to the COG and EuroNet-PHL.

Plasma thymus and activation-regulated chemokine (TARC) as diagnostic marker in pediatric Hodgkin lymphoma.

Pediatric classical Hodgkin's lymphoma (cHL) is characterized by Hodgkin Reed‐Sternberg cells located in an inflammatory microenvironment. Blood biomarkers result from active crosstalk between these cells. One promising biomarker in adult cHL patients is “thymus‐and‐activation‐regulated chemokine” (TARC). The objectives of this study were to define normal TARC values in non‐cHL children and to investigate and correlate pretherapy TARC as diagnostic marker in pediatric cHL. In this multicenter prospective study, plasma and serum samples were collected of newly diagnosed cHL patients before start of treatment (n = 49), and from randomly selected non‐cHL patients (n = 81). TARC levels were measured by enzyme‐linked immunosorbent assay. The non‐cHL patients had a median plasma TARC value of 71 pg/mL (range: 18‐762), compared to 14 619 pg/mL (range: 380‐73 174) in cHL patients (P < .001). TARC values had a high discriminatory power (AUC = .999; 95% confidence interval, .998‐1). A TARC cutoff level of 942 pg/mL maximized the sum of sensitivity (97.9%) and specificity (100%). TARC plasma levels were associated with age, treatment level, bulky disease, B‐symptoms, and erythrocyte sedimentation rate. TARC was found to be a highly specific and sensitive diagnostic marker for pediatric cHL. This noninvasive marker could be of great value as screening test in the work‐up for pediatric patients with lymphadenopathy.

Cyclooxygenase-2 expression as a prognostic factor in pediatric classical Hodgkin lymphoma.

Cyclooxygenase-2 (COX-2) is an inflammation-related enzyme that has been shown to have a role in tumor initiation, angiogenesis, and proliferation. It has been demonstrated that COX-2 expression is increased in many tumors and is a negative prognostic parameter. Our objective is to investigate the prognostic value of COX-2 expression in pediatric patients with classical Hodgkin lymphoma (CHL). This was a retrospective analysis in pediatric patients (n = 127) diagnosed with CHL and treated at the pediatric oncology department, National Cancer Institute, Cairo University, January 2005-June 2013. We correlated COX-2 immunostaining in Reed-Sternberg (RS) cells with clinical variables and outcome. COX-2 was expressed on 38.6% of RS cells. The median follow-up time was 48.4months (range 4-114months). The 5-year OS and PFS, in COX-2(+ve) versus COX-2(-ve) was 85.3% versus 96.0% (p = 0.248) and 78.6% versus 84.3% (p = 0.354), respectively. A multivariate analysis showed that COX-2(+ve) was not significantly associated with the 5-year OS (HR = 2.9; 95% CI 0.7-12.4, p = 0.149) or with the 5-year PFS (HR = 1.4; 95% CI 0.6-3.2, p = 0.490). High-risk patients in the COX-2(+ve) group had a significantly lower 5-year OS (p = 0.021). The 5-year PFS was significantly lower in the COX-2(+ve) group with B symptoms (p = 0.023) and bulky disease (p = 0.028). Radiotherapy was given only to high-risk patients; survival was much better in radiation-treated children in both the Cox-2(+ve) and Cox-2(-ve) groups. The magnitude of the radiotherapy effect was also greater in the Cox-2(+ve) group, but this difference was not statistically significant. COX-2 expression showed a tendency to be a poor prognostic factor, but it failed to provide meaningful independent information. Further larger studies are needed to investigate COX-2 as a prognostic factor and potential therapeutic target.

Pathway‐focused gene expression profiles and immunohistochemistry detection identify contrasting association of caspase 3 (CASP3) expression with prognosis in pediatric classical Hodgkin lymphoma

The search for clinically relevant molecular markers in classical Hodgkin lymphoma (cHL) is hampered by the histopathological complexity of the disease, resulting from the admixture of a small number of neoplastic Hodgkin and Reed-Sternberg (H-RS) cells with an abundant and heterogeneous microenvironment. In this study, we evaluated gene expression profiles of 11 selected genes previously proposed as a molecular score for adult cHL, aiming to validate its application in the pediatric setting. Assays were performed by RT-qPCR from formalin-fixed paraffin-embedded (FFPE) lymph nodes in 80 patients with cHL. Selected genes were associated with cell cycle (CENPF, CDK1, CCNA2, CCNE2, and HMMR), apoptosis (BCL2, BCL2L1, and CASP3), and monocytes/macrophages (LYZ and STAT1). Despite using controlled preanalytical and analytical strategies, we were not able to validate the 11-gene score to be applied in pediatric cHL. Principal component analysis (PCA) disclosed 3 components that accounted for 65.7% of the total variability. The second PC included microenvironment and apoptosis genes, from which CASP3 expression was associated with a short time of progression-free survival, which impact was maintained in the unfavorable risk group, Epstein-Barr virus-negative cases, and multivariate analysis (P<.05). Because this is a counterintuitive association, CASP3 active expression was assessed at the protein level in H-RS cells by double immunohistochemistry. In contrast to the association of mRNA levels with a poor therapeutic response, a high number of cleaved CASP3+ cells were associated with longer progression-free survival (P=.03) and overall survival (P=.002). Our results demonstrate the feasibility of using FFPE samples as RNA source for molecular prognostication, but argue against the concept of direct and wide applicability of molecular scores in cHL. We reinforce the potential of CASP3 as an interesting target to be explored in adult and pediatric cHL, and alert for its dual biological role in H-RS cells and tumor microenvironment.

Macrophage Polarization Reflects T Cell Composition of Tumor Microenvironment in Pediatric Classical Hodgkin Lymphoma and Has Impact on Survival

Macrophages have been implicated in the pathogenesis of classical Hodgkin lymphoma (cHL) and have been suggested to have a negative impact on outcome. Most studies addressing the role of macrophages in cHL have relied on identification of macrophages by generic macrophage antigens, e.g., CD68. We have therefore conducted an in situ analysis of macrophage polarization in a series of 100 pediatric cHL (pcHL) cases using double staining immunohistochemistry, combining CD68 or CD163 with pSTAT1 (M1-like) or CMAF (M2-like). M1- or M2-polarised microenvironment was defined by an excess of one population over the other (>1.5). Expression of STAT1 and LYZ genes was also evaluated by RT-qPCR. Patients <14 years and EBV+ cases displayed higher numbers of CD68+pSTAT1+ cells than older children and EBV- cases, respectively (P=0.01 and P=0.02). A cytotoxic tumor microenvironment, defined by a CD8+/FOXP3+ ratio >1.5 was associated with higher numbers of CD68+pSTAT1+ (P=0.025) and CD163+pSTAT1+ macrophages (P<0.0005). Levels of STAT1 and LYZ expression were associated with the numbers of CD68+pSTAT1+ macrophages. EBV+ cHL cases disclosed a predominant M1 polarized microenvironment similar to Th1 mediated inflammatory disorders, while EBV- cHL showed a predominant M2 polarized microenvironment closer to Th2 mediated inflammatory diseases. Better overall-survival (OS) was observed in cases with higher numbers of CD163+pSTAT1+ macrophages (P=0.02) while larger numbers of CD163+CMAF+ macrophages were associated with worse progression-free survival (PFS) (P=0.02). Predominant M1-like polarization as disclosed by CD163+pSTAT1+/CD163+CMAF+ ratio > 1.5 was associated with better OS (P= 0.037). In conclusion, macrophage polarization in pcHL correlates with prevalent local T cell response and may be influenced by the EBV-status of neoplastic cells. Besides, M1-like and M2-like macrophages displayed differential effects on outcome in pcHL.

Risk Adapted Therapy in Pediatric Classical Hodgkin Lymphoma

Risk Adapted Therapy in Pediatric Classical Hodgkin Lymphoma

Pediatric Hodgkin Lymphoma in a South Indian Regional Cancer Center: Its Immunomorphology, Tumor-Associated Macrophages, and Association with Epstein–Barr Virus

Pediatric Hodgkin lymphoma (HL) comprises approximately a fifth of all patients with HL in India. Seventy-four cases of pediatric classical Hodgkin Lymphoma (cHL) from a regional cancer center in southern India were analyzed on a tissue microarray (TMA) for the stage of B-cell differentiation of the Hodgkin/Reed Sternberg (HRS) cell by immunohistochemistry (IHC) using CD10, bcl6, MUM1/IRF4, and CD 138. Fifty-two of seventy-four (70.3%) cases were of late germinal center/early post-germinal center phenotype (CD10−/bcl6−/MUM1+/CD138−). Epstein–Barr virus (EBV) association using Epstein-Barr virus encoded RNA (EBER) RISH and EBV-LMP1 immunohistochemistry (IHC) revealed an EBV association of 93%. Tumor-associated macrophages (TAM) in the microenvironment were also assessed on the TMA by CD68 IHC, and most cases (59.7%) showed >25% TAMs, with no case showing ≤5%. These findings indicate that pediatric cHL in India is a tumor, predominantly, of late germinal center/early post-germinal center B cells, is almost invariably EBV associated, and with a high number of TAMs in the microenvironment. This latter finding suggests that criteria other than TAM scores need to be developed for risk stratification of pediatric EBV-associated HL especially in developing countries.

PD1+ Cells in Pediatric Classical Hodgkin Lymphoma is Associated with Better Outcome

Classical Hodgkin lymphoma (cHL) is characterized by few neoplastic cells in a background of inflammatory cells. Many studies have described the T cell composition of tumour microenvironment in adult cases and we have demonstrated differences between pediatric and adult cHL in this respect. Two studies recently described that high numbers of PD1+ cells were associated with worse survival in adult cHL. PD1 is a receptor expressed by CD8+ and CD4+ T cells upon activation, as well as by T follicular helper cells, exhausted CD8+ T cells and effector memory CD8+ T cells. The objective of this study was to evaluate PD1+ cells in 100 paediatric cHL cases (3 to 18 y, median: 14 y) using immunohistochemistry and computer assisted microscopical analysis. The results were compared with the other T-cell populations as determined in our previous study of these cases. A median of 5 PD1+ cells/mm2 was observed (1 to 363 cells/mm2), while 40% of cases did not show any PD1+ cell. A direct correlation was observed between the numbers of PD1+ and CD4+ cells (P = 0.018), as well as PD1+ and CD8+ cells (P = 0.02). Higher numbers of PD1+ cells were observed in cases with cytotoxic microenvironment profile (P = 0.016), as disclosed by the ratio TIA1+ cells/FOXP3+ cells > 1.5. The numbers of PD1+ cells were not associated with age group or EBV-status. Cases with higher numbers of PD1+ cells (> 5 cells/mm2) were associated with better 5-years overall survival (P = 0.019). Our results suggest that the majority of PD1+ cells in the tumour microenvironment of paediatric cHL may contribute to the immune response against the neoplastic cells. A more detailed characterization of these cells is in progress.

Tumor-Associated Macrophages in Pediatric Classical Hodgkin Lymphoma: Association with Epstein-Barr Virus, Lymphocyte Subsets, and Prognostic Impact

Tumor-infiltrating macrophages are associated with adverse outcome in adult classical Hodgkin lymphoma (cHL). We have previously shown age-related changes in the lymphocyte composition of pediatric cHL. We therefore hypothesized that the number, function, and prognostic impact of macrophages in pediatric cHL would be different from adult cases. We analyzed the number of macrophages and dendritic cells (DC) in the tumor microenvironment of pediatric cHL by immunohistochemistry. Results were analyzed in context of age, histologic characteristics, Epstein-Barr virus (EBV) status, clinical follow-up, and our previous study of T-cell populations in these cases. One hundred cHL cases were studied, including 69% nodular sclerosis and 23% mixed cellularity cases. A total of 44.8% of cases were EBV-positive. Patients ≤10 years displayed more CD14(+) cells (P = 0.025). In comparison with nodular sclerosis, mixed cellularity was characterized by higher numbers of CD14(+), (P = 0.003) and CD163(+) cells (P = 0.027). EBV(+) cases exhibited higher numbers of CD14(+) (P < 0.0005), CD68(+) (P = 0.005), and CD163(+) cells (P = 0.02). CD68-positive cells did not display an effect on outcome. Worse overall survival was observed in cases with CD163/CD8 ratio ≥2 (P = 0.007). High numbers of CD163(+) cells were associated with worse progression-free survival (PFS; P = 0.015). Furthermore, high numbers of CD163(+) and granzyme B(+) cells were associated with worse PFS in EBV-negative (P = 0.005) but not in EBV-positive cases. Our results suggest that macrophage composition in pediatric cHL is distinct from adults. Functional status of macrophages and their value as prognostic indicators in pediatric cHL may depend on EBV status.

Tumor microenvironment composition in pediatric classical Hodgkin lymphoma is modulated by age and Epstein‐Barr virus infection

Classical Hodgkin lymphoma (cHL) is characterized by a small number of neoplastic cells in a background of reactive cells. Children and adults differ in constitution and functionality of the immune system and it is possible that there may be age-related differences in tumor microenvironment composition in cHL. One hundred children with pediatric cHL were studied. Tumor-infiltrating lymphocytes were analyzed by immunohistochemistry (IHC) and image analysis. Epstein-Barr virus (EBV) status was determined by EBER-specific in situ hybridization and IHC. Results were analyzed in the context of age-group, histological characteristics and clinical follow-up. EBV-status was not associated with age-group. Children<10 years and EBV+ cases were characterized by a more intense T cell infiltrate, exhibiting a cytotoxic/Th1 profile, characterized by higher numbers of CD3+, CD8+, TIA1+ and TBET+ lymphocytes. Extranodal disease (p=0.016) and high number of GranzymeB+ lymphocytes (p=0.04) were independently associated with reduced progression-free survival (PFS). Yet, in EBV+ cases, improved outcome was observed in cases with low numbers of FOXP3+ lymphocytes (p=0.046), FOXP3/CD8 ratio<1 (p=0.021) and TBET/CMAF ratio<1 (p=0.017). By contrast, in EBV- cases, poor survival was observed in cases with extranodal disease (p=0.028), MC subtype (p=0.009) and high numbers of TIA1+ (p=0.044) and GranzymeB+ (p=0.04) lymphocytes. The results suggest that in EBV+ cHL an effective immune response directed against viral or tumor antigens may be triggered in the tumor microenvironment and that physiological and age-related changes of the immune system may also modulate the tumor microenvironment in pediatric cHL.

Disease patterns in pediatric classical Hodgkin lymphoma: a report from a developing area in Brazil

Epidemiological patterns established about 20 years ago, divided classical Hodgkin lymphoma (cHL) in three entities with regard to Epstein-Barr virus (EBV) status and histological subtypes and suggested different epidemiological patterns associated with degree of economic development. Here, we investigated histopathological features and EBV association in 100 consecutive pediatric cHL cases occurring in Rio de Janeiro (Brazil). Age at diagnosis ranged from 3 to 18 years (median 14 years) with 27% of cases ≤10 years. Unexpectedly, we did not observe an early childhood peak with most cases occurring in the >10 years age group. Nodular sclerosis (NS) was the most frequent subtype (69%) and was more frequently observed in the >10 years age group, followed by mixed cellularity (MC, 23%) which was distributed equally between age groups. EBV was identified in 44.8% of cases, without preferential association with age groups (≤10 years vs. >10 years). MC cases were independently associated with EBV infection of tumour cells (p = 0.045) and with a CD4/CD20 ratio <1 in the microenvironment (p = 0.014). Our results suggest that a gradual shift from childhood peak to early adulthood peak may be observed in developing regions. The development of MC subtype may result from early exposure to EBV in the context of an impaired immune system reflected by a CD4/CD20 ratio <1. Conversely, it is possible that NS originates predominantly in the context of a better immune response against EBV and/or tumour antigens expressed in the neoplastic cells.

Unfavorable outcome in CD15 negative pediatric classical Hodgkin lymphoma

Unfavorable outcome in CD15 negative pediatric classical Hodgkin lymphoma

Proliferative index and CD15 expression in pediatric classical Hodgkin lymphoma

This study was conducted to assess the clinical and prognostic significance of lack of CD15 expression, proliferative index (PI), and expression of tumor suppressor protein p53 in pediatric classical Hodgkin lymphoma (CHL). Pre-treatment lymph node (LN) biopsies were studied by immunohistochemistry for immunophenotyping of the lymphoma and with Ki-67 (PI) and p53 antibodies. Expression of CD15 antigen on the Hodgkin and Reed-Sternberg (H-RS) cells, proliferation, and apoptosis parameters were correlated with clinical stage, response to chemotherapy alone, overall (OS) and failure-free survival (FFS). One hundred and twenty-one children with CHL were studied. Expression of Ki-67 and p53 in H-RS cells was seen in 100% and 89.9% of the cases, respectively. Loss of CD15 expression, seen in 12 (9.9%) cases, was significantly associated with p53 negativity and was an independent prognostic factor for poor OS and poor FFS. PI </= 74% was an independent prognostic factor for poor FFS. Loss of CD15 expression in CHL might be related to p53 dysregulation. High PI in HL might reflect a high level of endomitosis within tumor cells, and could lead to higher sensitivity to chemotherapy. Low pre-treatment PI and lack of CD15 expression were found to be predictive factors for poor FFS in pediatric CHL.