The many faces of Hodgkin's disease around the world: what have we learned from its pathology?

Classic Hodgkin lymphoma in Guatemalan children of age less than six years: analysis of immune regulatory pathways and the tumor microenvironment

Classic Hodgkin lymphoma (cHL) in young children (ages 0-6) is rare in high income countries (HICs) but is more prevalent in low- and middle-income countries (LMICs) like Guatemala. Given that the majority of cHL studies have evaluated adolescent/adults, and the immune system changes with age, we sought to characterize Epstein-Barr virus (EBV) expression, immune regulatory pathway markers and the tumor microenvironment in 42 children ages 0-6 with cHL from Guatemala. We found a very high frequency of EBV expression (97.5%). Hodgkin cells showed increased expression of PD1 ligands and CD137, indicative of shared immune regulatory mechanisms with adult cHL. Pediatric cHL also showed an increase in CD8+ tumor infiltrating lymphocytes and tumor associated macrophages within the tumor microenvironment. Despite 25 having high risk disease, only 4 patients died from progressive disease, relapse or infection.

Socioeconomic deprivation and regional variation in Hodgkin's lymphoma incidence in the UK: a population-based cohort study of 10 million individuals

OBJECTIVES

Hodgkin's lymphoma (HL) is the the most common cancer in teenagers and young adults. This nationwide study conducted over a 25-year period in the UK investigates variation in HL incidence by age, sex, region and deprivation to identify trends and high-risk populations for HL development.

DESIGN

Population-based cohort study.

SETTING

Clinical Practice Research Datalink (CPRD) electronic primary care records linked to Hospital Episode Statistics and Index of Multiple Deprivation data were used.

PARTICIPANTS

Data on 10 million individuals in the UK from 1992 to 2016 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Poisson models were used to explore differences in HL incidence by age, sex, region and deprivation. Age-specific HL incidence rates by sex and directly age-standardised incidence rates by region and deprivation group were calculated.

RESULTS

A total of 2402 new cases of HL were identified over 78 569 436 person-years. There was significant variation in HL incidence by deprivation group. Individuals living in the most affluent areas had HL incidence 60% higher than those living in the most deprived (incidence rate ratios (IRR) 1.60, 95% CI 1.40 to 1.83), with strong evidence of a marked linear trend towards increasing HL incidence with decreasing deprivation (p=<0.001). There was significant regional variation in HL incidence across the UK, which persisted after adjusting for age, sex and deprivation (IRR 0.80-1.42, p=<0.001).

CONCLUSIONS

This study identified high-risk regions for HL development in the UK and observed a trend towards higher incidence of HL in individuals living in less deprived areas. Consistent with findings from other immune-mediated diseases, this study supports the hypothesis that an affluent childhood environment may predispose to development of immune-related neoplasms, potentially through fewer immune challenges interfering with immune maturation in early life. Understanding the mechanisms behind this immune dysfunction could inform prevention, detection and treatment of HL and other immune diseases.

Lower socioeconomic status is independently associated with shorter survival in Hodgkin Lymphoma patients-An analysis from the Brazilian Hodgkin Lymphoma Registry

Socioeconomic status (SES) is a well-known determinant of outcomes in cancer. The purpose of this study was to analyze the impact of the SES on the outcomes of Hodgkin lymphoma (HL) patients from the Brazilian Prospective HL Registry. SES stratification was done using an individual asset/education-based household index. A total of 624 classical HL patients with diagnosis from January/2009 to December/2014, and treated with ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine), were analyzed. The median follow-up was 35.6 months, and 33% were classified as lower SES. The 3-year progression- free survival (PFS) in higher and lower SES were 78 and 64% (p < 0.0001), respectively. The 3-year overall survival (OS) in higher and lower SES were 94 and 82% (p < 0.0001), respectively. Lower SES patients were more likely to be ≥ 60 years (16 vs. 8%, p = 0.003), and to present higher risk International Prognostic score (IPS) (44 vs. 31%, p = 0.004) and advanced disease (71 vs. 58%, p = 0.003). After adjustments for potential confounders, lower SES remained independently associated with poorer survival (HR = 3.12 [1.86-5.22] for OS and HR = 1.66 [1.19-2.32] for PFS). The fatality ratio during treatment was 7.5 and 1.3% for lower and higher SES (p = 0.0001). Infections and treatment toxicity accounted for 81% of these deaths. SES is an independent factor associated with shorter survival in HL in Brazil. Potential underlying mechanisms associated with the impact of SES are delayed diagnosis and poorer education. Educational and socio-economic support interventions must be tested in this vulnerable population.

Treatment outcomes for Hodgkin lymphoma: First report from the Brazilian Prospective Registry

Data about Hodgkin lymphoma (HL) in developing countries are scarce and suggest the existence of substantial disparities in healthcare and outcomes in large areas of the world. In 2009, a prospective registry of HL was implemented in Brazil. Web-based data were contributed by 20 institutions across the country participating in the Brazilian Prospective Hodgkin's Lymphoma Registry. The aim of this study was to present the clinical features and outcomes of newly diagnosed patients with HL aged 13 to 90 years. Multivariate Cox regression models were used to estimate progression-free (PFS) and overall survival (OS) by clinical factors. A total of 674 patients with classical HL were analysed, with a median follow-up of 37 months. Median age was 30 years (13-90). The median time from the onset of symptoms to diagnosis was 6 months (0-60). Only 6% of patients had early favourable disease, while 65% had advanced disease. Stage IVB was present in 26% and a high-risk International Prognostic Score in 38%. Doxorubicin, bleomycin, vinblastine, and dacarbazine was used in 93%. The median dose of radiotherapy was 36 Gy for localized disease and 32 Gy for advanced disease. The 3 year PFS in early favourable, early unfavourable, and advanced disease were 95%, 88%, and 66%, respectively. High-risk International Prognostic Score, advanced disease, and age greater than or equal to 60 were independently associated with poorer PFS and OS; performance status greater than or equal to 2 was also associated with a poorer OS. Poor-risk patients predominated. Radiation doses for localized disease appear higher than current recommendations. Outcomes appear inferior in developing countries than in developed countries. Delayed diagnosis is probably a major factor underlying these findings. Scattered reports from developing nations suggest that many aspects of standard care in developed countries remain unmet needs for populations living in developing countries. The present report contributes to this body of data, with a proper description of what is currently achieved in urban areas in Brazil.

Epstein-Barr virus and Hodgkin lymphoma in Jordan

BACKGROUND AND OBJECTIVES

This study aims to examine the possible association of Epstein-Barr virus (EBV) in Classical Hodgkin lymphoma (cHL) and to shed light on the epidemiology of Hodgkin lymphoma (HL) in Jordan.

PATIENTS AND METHODS

We examined 100 consecutive cases of HL for the presence of EBV in tumor cells by immunohistochemistry for latent membrane protein-1 (LMP-1). We collected patient data on age, sex and histologic subtype. We reviewed the pathological findings in each case and confirmed diagnosis.

RESULTS

Nodular lymphocyte predominant HL was diagnosed in 6% of the cases and these were negative for EBV LMP-1. Of the 94 cases of cHL, 65% were males, the most common subtype was nodular sclerosis (NS), representing 70% of the cases, and 45.7% of cHL (43% of all HL) cases were positive for EBV LMP-1. The positive cases were significantly related to age: ⩽15 years and >51 years (p: 0.009 and 0.014 respectively), male gender (p: 0.03) and mixed cellularity (MC) subtype (p: <0.0001). In line with other developing countries, there also appears to be a trend towards a decreasing association of EBV with cHL and a subtype switch from MC to NS in Jordan.

CONCLUSION

The epidemiology of HL in Jordan and some developing countries is approaching that of developed countries.

Epstein-Barr virus (EBV) positive classical Hodgkin lymphoma of Iraqi children: an immunophenotypic and molecular characterization of Hodgkin/Reed-Sternberg cells

BACKGROUND

Classical Hodgkin lymphoma (cHL) in children is often associated with EBV infection, more commonly in developing countries.

PROCEDURE

Here we describe the histological, immunohistochemical, and molecular features of 57 cases of HL affecting Iraqi children under 14 years of age.

RESULTS

Histologically, 51 cases were classified as cHL of Mixed Cellularity and Nodular Sclerosis subtypes (MC = 69%; NS = 31%), and 6 cases as Nodular Lymphocyte Predominant HL (NLP-HL). EBV infection of H/RS cells was demonstrated in 44 of 51 cases of cHL (86%), and was more common in MC than in NS (97% vs. 63%; P = 0.0025). The immunophenotypic profile of H/RS cells was similar in MC and NS, and was not influenced by EBV infection; H/RS cells were consistently positive for PAX-5 and to a lesser degree for other B cell markers including CD20/CD79a, OCT-2, and BOB-1. Clonal IGH rearrangements were detected in 14 of 38 cHL (37%), with no significant difference between MC and NS cases, and with no association with the EBV status. Oligoclonal/monoclonal TCRγ rearrangements were present in 28 of 38 cases (74%), suggestive of restricted T cell responses.

CONCLUSIONS

Our findings indicate that cHL occurring in Iraqi children is characterized by immunohistochemical and molecular features undistinguishable from those present in cHL occurring elsewhere in the world. Moreover, the high incidence of EBV-infected H/RS cells and frequent occurrence of restricted T cell responses might be indicative of a defective local immune response perhaps related to the very young age of the children.

EBV primary infection in childhood and its relation to B-cell lymphoma development: a mini-review from a developing region

In most underdeveloped countries, the initial contact with Epstein Barr virus (EBV) usually happens in the first decade of life and results in an asymptomatic infection, whereas in developed areas, primary infection in adolescence or adulthood is accompanied by infectious mononucleosis in 50% cases. Although it is generally a harmless passenger, in some individuals, it is associated with B-cell lymphoma. In Argentina, EBV primary infection shows the classical pattern observed in developing populations, given that nearly 70% of patients are seropositive by the age of 2 years. However, EBV association with pediatric Hodgkin and Burkitt lymphoma resembles that observed in developed regions. Concerning diffuse large B-cell lymphoma, our series demonstrated higher EBV association than other adult ones from either developed or underdeveloped countries. Interestingly, the early EBV primary infection observed, characteristic of an underdeveloped population, together with the statistically significant EBV association with patients ≤ 10 years old demonstrated in all types of lymphoma studied, suggest a relationship between low age of EBV seroconversion and B-cell lymphoma development risk.

NF-κB as a target for oncogenic viruses

NF-κB is a pivotal transcription factor that controls cell survival and proliferation in diverse physiological processes. The activity of NF-κB is tightly controlled through its cytoplasmic sequestration by specific inhibitors, IκBs. Various cellular stimuli induce the activation of an IκB kinase, which phosphorylates IκBs and triggers their proteasomal degradation, causing nuclear translocation of activated NF-κB. Under normal conditions, the activation of NF-κB occurs transiently, thus ensuring rapid but temporary induction of target genes. Deregulated NF-κB activation contributes to the development of various diseases, including cancers and immunological disorders. Accumulated studies demonstrate that the NF-κB signaling pathway is a target of several human oncogenic viruses, including the human T cell leukemia virus type 1, the Kaposi sarcoma-associated herpesvirus, and the Epstein-Bar virus. These viruses encode specific oncoproteins that target different signaling components of the NF-κB pathway, leading to persistent activation of NF-κB. This chapter will discuss the molecular mechanisms by which NF-κB is activated by the viral oncoproteins.

Pediatric Hodgkin lymphoma in 2 South American series: a distinctive epidemiologic pattern and lack of association of Epstein-Barr virus with clinical outcome

Hodgkin lymphoma (HL) shows a bimodal distribution with a first peak in developing countries during childhood. The causative role and prognostic significance of Epstein-Barr virus (EBV) association in patients with HL is controversial. Our aim was to perform a comparative study of EBV association in 2 Latin American pediatric HL series, and to correlate it with patient's survival. Epstein-Barr encoded RNAs in situ hybridization and latent membrane protein 1 immunohistochemistry were performed on formalin-fixed, paraffin-embedded HL biopsies from 176 pediatric patients from 2 public institutions from Argentina and Southeast Brazil. Mixed cellularity subtype was prevalent in Argentine HL (Arg HL) (52%) and nodular sclerosis subtype in Brazilian HL (BR HL) (83%). EBV expression was detected in 52% of cases, namely 54% Arg HL and 48% Br HL. EBV was significantly associated with mixed cellularity subtype in both populations. In Arg HL, EBV positivity was significantly higher in patients<or=10 years (P=0.0011). Event-free survival did not attain statistical significance neither in Arg HL (P=0.5317), nor in Br HL (P=0.8321). Our results do not support EBV association stated for pediatric HL in developing countries. Correlation of younger age with EBV infection only in Argentine patients might be related to a different age background. In our pediatric series, EBV status cannot be used as prognostic factor.

Comparison of Epstein-Barr virus presence in Hodgkin lymphoma in pediatric versus adult Argentine patients

CONTEXT

In developed countries and high socioeconomic groups, Hodgkin lymphoma has an initial peak in young adulthood, whereas in undeveloped countries and low socioeconomic groups, it shows an early childhood peak. In developing countries, 90% of children are infected with the Epstein-Barr virus (EBV) by the age of 6 years, but in developed countries, only 30% to 40% are seropositive by that age. Early childhood EBV infection in 75% of Argentine patients was demonstrated.

OBJECTIVE

To explore the epidemiology of Hodgkin lymphoma and its relationship with EBV in Argentine patients.

METHODS

The presence of EBV was assessed by Epstein-Barr encoded RNA in situ hybridization and latent membrane protein 1 immunohistochemistry. We studied 92 pediatric and 42 adult Hodgkin lymphoma cases from a public center as well as 39 adult cases from a private center.

RESULTS

The mixed cellularity Hodgkin lymphoma had a prevalence of 52% in the pediatric group, while similar frequencies of both nodular sclerosis Hodgkin lymphoma (47%) and mixed cellularity Hodgkin lymphoma (44%) were observed in adults. As for Epstein-Barr encoded RNAs, 55% of the pediatric cases and 31% of the adult cases were positive. Among adult EBV+ cases, 38% were from the public hospital, and 23% were from the private center. EBV was present in 77% of the pediatric mixed cellularity Hodgkin lymphoma cases when compared with the other histologic subtypes of Hodgkin lymphoma. EBV was mainly detected in mixed cellularity cases (39% in the adult group).

CONCLUSION

Our findings strengthen the argument that EBV is involved in the pathogenesis of Hodgkin lymphoma in most children younger than 10 years. Our findings of EBV prevalence, along with both childhood and second-decade peaks as well as comparable frequencies for Hodgkin lymphomas of mixed cellularity and nodular sclerosis, distinguish our population from others in developing countries.

Epstein-Barr virus expression in Hodgkin's lymphoma in Kuwait

The epidemiology of Hodgkin's lymphoma (HL) shows wide geographic variation in histological subtypes and in its association with the Epstein-Barr virus (EBV). The proportion of EBV positive HL is low in industrialized countries, high in non-industrialized countries and intermediate in early-industrialized countries. Reports from the Persian Gulf and Middle East are very limited. The aim of this study was to determine the epidemiology of HL in Kuwait, an early-industrialized country in the Persian Gulf, and to delineate the extent of its association with EBV. We reviewed 134 cases of HL for histological classification and demographic data. 107 cases were examined for the presence of EBV using immunohistochemistry (IHC) for the latent membrane protein I (LMPI) and in-situ hybridization (ISH) for EBVencoded RNA (EBER). 70.4% of the patients were males and 29.6% were females. The male: female ratio was 2.4:1. The mean age was 30.6 years (range, 4-71 years). Mixed cellularity HL (MCHL) was the most common subtype (45.5%), followed by nodular sclerosis (37.3%), nodular lymphocyte predominant (6.7%), lymphocyte rich (3%) and lymphocyte depletion (3%). 4.5% of cases were unclassifiable. EBV expression was seen in 56%, was significantly higher in MCHL, in children, and in males. Our findings suggest that the frequency of EBV expression in HL in Kuwait is similar to other early-industrialized countries. Further research from other countries in the Persian Gulf and the Middle East should shed more light on the epidemiology of HL and its relation to EBV in this region.

Estimates of cancer incidence and mortality in Europe in 1995

Cancer incidence and mortality estimates for 1995 are presented for the 38 countries in the four United Nations-defined areas of Europe, using World Health Organization mortality data and published estimates of incidence from national cancer registries. Additional estimation was required where national incidence data was not available, and the method involved incorporating the high quality incidence and mortality data available from the expanding number of population-based cancer registries in Europe. There were an estimated 2.6 million new cases of cancer in Europe in 1995, representing over one-quarter of the world burden of cancer. The corresponding number of deaths from cancer was approximately 1.6 million. After adjusting for differing population age structures, overall incidence rates in men were highest in the Western European countries (420.9 per 100,000), with only Austria having a rate under 400. Eastern European men had the second highest rates of cancer (414.2), with extremely high rates being observed in Hungary (566.6) and in the Czech Republic (480.5). The lowest male all-cancer rate by area was observed in the Northern European countries, with fairly low rates seen in Sweden (356.6) and the UK (377.8). In contrast to men, the highest rates in women were observed in Northern Europe (315.9) and were particularly high in Denmark (396.2) and the other Nordic countries excepting Finland. The rates of cancer in Eastern European women were lower than in the other three areas, although as with men, female rates were very high in Hungary (357.2) and in the Czech Republic (333.6). There was greater disparity in the mortality rates within Europe--generally, rates were highest in Eastern European countries, notably in Hungary, reflecting a combination of poorer cancer survival rates and a higher incidence of the more lethal neoplasms, notably cancer of the lung. Lung cancer, with an estimated 377,000 cases, was the most common cancer in Europe in 1995. Rates were particularly high in much of Eastern Europe reflecting current and past tobacco smoking habits of many of its inhabitants. Together with cancers of colon and rectum (334,000), and female breast (321,000), the three cancers represented approximately 40% of new cases in Europe. In men, the most common primary sites were lung (22% of all cancer cases), colon and rectum (12%) and prostate (11%), and in females, breast (26%), colon and rectum (14%) and stomach (7%). The number of deaths is determined by survival, as well as incidence; by far the most common cause of death was lung cancer (330,000)--about one-fifth of the total number of cancer deaths in Europe in 1995. Deaths from cancers of the colon and rectum (189,000) ranked second, followed by deaths from stomach cancer (152,000), which due to poorer survival ranked higher than breast cancer (124,000). Lung cancer was the most common cause of death from cancer in men (29%). Breast cancer was the leading cause of death in females (17%). Cancer registries are a unique source of information on cancer incidence and survival, and are used here with national mortality to demonstrate the very substantial burden of cancer in Europe, and the scope for prevention. Despite some provisos about data quality, the general patterns which emerge in Europe verify the role of past exposures and interventions, and more importantly, firmly establish the need for cancer control measures which target specific populations. In particular, there is a clear urgency to combat the ongoing tobacco epidemic, now prevalent in much of Europe, particularly in the Eastern countries.

Concurrent Hodgkin's disease (mixed cellularity type) and T-cell chronic lymphocytic leukemia/prolymphocytic leukemia

We describe a patient with leukopenic T-cell chronic lymphocytic leukemia/prolymphocytic leukemia (T-CLL/PLL), according to the Revised European-American Classification of Lymphoid Neoplasms. This patient simultaneously developed classic Hodgkin's disease (HD), a combination previously unreported. The leukemic cells were small and mature, did not have cytoplasmic granulation, and appeared similar to B-cell chronic lymphocytic leukemia. Immunophenotyping of the bone marrow-infiltrating cells revealed a postthymic suppressor/cytotoxic phenotype of CD2+, CD3+, CD4, CD5+, CD8+, CD25-, TCR-alpha beta. A lymph node biopsy showed the histological features of HD (mixed cellularity) with infiltrating CD8+ lymphocytes, and immunohistochemical examination revealed the following phenotype of Reed-Sternberg cells: LeuM1/CD15+, BerH2/CD30+, L26/PanB-, UCHL-1/CD45RO-, cyCD3-, CD4, CD8-, CD20-, CD79a-, EMA-, EBER-1+, LMP-1+. Southern blot analysis of the bone marrow and lymph node revealed the same rearrangement of bands of T-cell-receptor genes. Although the HD was treated with chemotherapy that resulted in complete remission, the T-PLL/CLL took an indolent course. This case may suggest the existence of a subtype of T-CLL/PLL with leukopenia and an indolent clinical course. Both diseases were believed to be independent and not a transformation of one to the other.

Molecular morphology of Hodgkin lymphoma

No other disease entity has provided greater impetus for the development of the concept of "molecular morphology" than Hodgkin lymphoma. Efforts to understand the etiology of this enigmatic disease have stimulated the application and refinement of almost every mode of biomedical scientific exploration. Notwithstanding the vast amount of data generated, much is still unknown about this remarkable disease, serving as an ongoing inducement to the development and application of new technologies for the analysis of cells and molecules in a morphologic environment.

The classification of lymphomas and leukemias

Classifications of lymphomas and leukemias have developed from two distinct clinical needs - to understand the natural history of these diseases in order to predict outcome and to make treatment decisions in a rational fashion. The utility of classifications for research on etiology of these diseases has not guided their development in the past. The classification of leukemias and lymphomas has undergone dramatic changes with increasing understanding of the development of the normal immune cells. Historically, the first entity to be recognised was Hodgkin disease. Other malignancies of the lymphatic system were then called 'Non-Hodgkin Lymphomas' (NHL), a distinction that remains valid even today. Cancers that tend not to form distinct masses but usually present with a raised white blood cell count were called leukemias. As knowledge has improved, however, the early juxtaposition of leukemias versus lymphomas has lost relevance, since often the same entity can present in either way. With better understanding the terms 'lymphosarcoma' and 'reticulosarcoma', which were earlier widely applied have been replaced by more precise terminology. Different classifications have been put forward over the years. The 'Revised European and American Classification of Lymphoid Neoplasms' and the derived WHO classification are structured to mirror normal B/T-cell differentiation. In these modern classifications, distinct disease entities are defined based on the combination of morphology, immunological and molecular techniques and clinical features. The proposed major groups of lymphoid neoplasms are B-cell lymphomas/leukemias, T/Natural Killer-cell lymphomas/leukemias and Hodgkin disease. About 20 entities are recognised. This provides for the first time a truly international view of lymphomas and leukemias. It has emerged that such a classification can be used successfully by expert hematopathologists and yields highly reproducible results. It is also clear that no single marker, be it morphology, genetic analysis or immunophenotyping can be used as the 'gold standard' for diagnosis but that a combination of techniques is needed.

Marked decrease in the Epstein-Barr virus positivity rate in nodular sclerosis subtype Hodgkin's disease in Tokyo: trend between 1955 and 1999

We studied the trends of the Epstein-Barr virus (EBV) positivity rate in Hodgkin's disease (HD) between 1955 and 1999. The overall positivity rate gradually decreased over time [12 out of 23 (52%) in 1955-69; 18 out of 39 (46%) in 1970-84; 13 out of 44 (35%) in 1985-99; P = 0.135]. Interestingly, a marked decrease in the rate was noted in the nodular sclerosis (NS) subtype [5 out of 11 (45%); 4 out of 19 (21%); 1 out of 24 (4%); P < 0.01] but not in other classic HD [7 out of 11 (63%); 14 out of 18 (78%); 12 out of 18 (67%); P = 0.775]. Our results indicate that the EBV positivity rate in HD has decreased over time and that this trend reflected the increasing incidence of EBV-negative NS.

Epstein-Barr virus association in classical Hodgkin's disease provides survival advantage to patients and correlates with higher expression of proliferation markers in Reed-Sternberg cells

BACKGROUND

Most Epstein-Barr virus (EBV) associated lymphoproliferative disorders have high proliferation indices. However, classical Hodgkin's disease (cHD) is heterogeneous, with respect to proliferation index of the Reed-Sternberg cell (RS cell), and EBV association. Hence, we investigated whether cHD with and without EBV-association differ with respect to the proliferation index of the RS cells. Further we investigated whether this would have a bearing on patients survival.

PATIENTS AND METHODS

We investigated 110 cases of cHD for: a) EBV association by immunohistochemical demonstration of EBV-latent membrane protein-1 and EBV encoded nuclear RNA 1 by mRNA in situ hybridisation; b) Proliferating cell nuclear antigen (PCNA) expression in the RS cells.

RESULTS

EBV association was noted in 86 of 110 cases (78%). Higher PCNA expression (P = 0.004) and younger age (P = 0.001) correlated independently with EBV association. The 10 year relapse free survival (RFS) of EBV+ and EBV- patients were 60% and 44%, respectively (P = 0.03). The 10 year overall survival (OS) of EBV+ and EBV- patients were 85% and 64%, respectively (P = 0.03). EBV association maintained its significant impact on RFS and OS within Cox proportional hazard model.

CONCLUSIONS

Our study suggests that EBV is likely to confer a higher PCNA expression and also contribute towards maintaining the RS cells of cHD in cell cycle. Hence, RS cells in EBV associated cHD would be more responsive to chemotherapy and radiotherapy associated DNA damage. Thus, EBV-association provides survival advantage to cHD patients treated with standard chemotherapy and radiotherapy protocols.