Prospective measurement of Epstein-Barr virus-DNA in plasma and peripheral blood mononuclear cells of extranodal NK/T-cell lymphoma, nasal type. Blood. 2011;118:6018-6022. [PMID: 21984805 DOI: 10.1182/blood-2011-05-354142]

A differential diagnosis method for systemic CAEBV and the prospect of EBV-related immune cell markers via flow cytometry

Chronic active Epstein-Barr virus (CAEBV) infection of the T-cell or Natural killer (NK)-cell type, systemic form (systemic CAEBV or sCAEBV) was defined by the WHO in 2017 as an EBV-related lymphoproliferative disorder and is listed as an EBV-positive T-cell and NK-cell proliferation. The clinical manifestations and prognoses are heterogeneous. This makes systemic CAEBV indistinguishable from other EBV-positive T-cell and NK-cell proliferations. Early diagnosis of systemic CAEBV and early hematopoietic stem cell transplantation can improve patient prognosis. At present, the diagnosis of systemic CAEBV relies mainly on age, clinical manifestations, and cell lineage, incurring missed diagnosis, misdiagnosis, long diagnosis time, and inability to identify high-risk systemic CAEBV early. The diagnostic methods for systemic CAEBV are complicated and lack systematic description. The recent development of diagnostic procedures, including molecular biological and immunological techniques such as flow cytometry, has provided us with the ability to better understand the proliferation of other EBV-positive T cells and NK cells, but there is no definitive review of their value in diagnosing systemic CAEBV. This article summarizes the recent progress in systemic CAEBV differential diagnosis and the prospects of flow cytometry.

Resistance mechanisms and potential therapeutic strategies in relapsed or refractory natural killer/T cell lymphoma

ABSTRACT

Natural killer/T cell lymphoma (NKTCL) is a malignant tumor originating from NK or T cells, characterized by its highly aggressive and heterogeneous nature. NKTCL is predominantly associated with Epstein-Barr virus infection, disproportionately affecting Asian and Latin American populations. Owing to the application of asparaginase and immunotherapy, clinical outcomes have improved significantly. However, for patients in whom first-line treatment fails, the prognosis is exceedingly poor. Overexpression of multidrug resistance genes, abnormal signaling pathways, epigenetic modifications and active Epstein-Barr virus infection may be responsible for resistance. This review summarized the mechanisms of resistance for NKTCL and proposed potential therapeutic approaches.

CDK4/6 inhibition augments anti-tumor efficacy of XPO1 inhibitor selinexor in natural killer/T-cell lymphoma

XPO1 is an attractive and promising therapeutic target frequently overexpressed in multiple hematological malignancies. The clinical use of XPO1 inhibitors in natural killer/T-cell lymphoma (NKTL) is not well documented. Here, we demonstrated that XPO1 overexpression is an indicator of poor prognosis in patients with NKTL. The compassionate use of the XPO1 inhibitor selinexor in combination with chemotherapy showed favorable clinical outcomes in three refractory/relapsed (R/R) NKTL patients. Selinexor induced complete tumor regression and prolonged survival in sensitive xenografts but not in resistant xenografts. Transcriptomic profiling analysis indicated that sensitivity to selinexor was correlated with deregulation of the cell cycle machinery, as selinexor significantly suppressed the expression of cell cycle-related genes. CDK4/6 inhibitors were identified as sensitizers that reversed selinexor resistance. Mechanistically, targeting CDK4/6 could enhance the anti-tumor efficacy of selinexor via the suppression of CDK4/6-pRb-E2F-c-Myc pathway in resistant cells, while selinexor alone could dramatically block this pathway in sensitive cells. Overall, our study provids a preclinical proof-of-concept for the use of selinexor alone or in combination with CDK4/6 inhibitors as a novel therapeutic strategy for patients with R/R NKTL.

Primary Testicular Extranodal NK/T-cell Lymphoma Nasal Type Associated With Epstein-Barr Virus Infection: A Moroccan Case Report

Epstein-Barr virus (EBV) is a ubiquitous and potentially oncogenic human herpesvirus. In this article, we discuss a rare case of primary testicular NK/T-cell lymphoma, nasal type, associated with high plasma Epstein-Barr virus DNA load. The patient, a 45-year-old man, presented with painful testicular swelling, fever, and weight loss. An orchiectomy revealed tumor proliferation, which was diagnosed as testicular NK/T cell lymphoma, nasal type, confirmed by immunohistochemistry, and classified as stage IV according to the Ann Arbor classification. The patient was treated with SMILE chemotherapy. After treatment, a PET scan showed complete remission with negative EBV DNA levels. The discussion focused on the role of EBV in the development of this malignant lymphoproliferation and the importance of quantifying EBV DNA load by real-time PCR in assessing prognosis, patient follow-up, and response to treatment.

Extranodal nasal-type NK/T lymphoma treated with chemotherapy and radiotherapy: case series from a European tertiary referral center and review of the literature

PURPOSE

Extranodal nasal-type NK/T-cell lymphoma (ENKTL) is very rare in western countries and few data are available regarding the prognosis and the outcome of patients treated for this disease. We aimed to evaluate the prognosis, the pattern and risk factors of disease failure after combined therapy and also performed a review of the literature.

PATIENTS AND METHODS

We retrospectively analyzed 20 patients with (ENKTL) who underwent L‑Asparaginase based chemotherapy followed by (chemo-) radiotherapy between 2010 and 2020 in our center. Data on clinical characteristics and irradiation were collected. Failure patterns were recorded as local (tumor site), regional (regional lymph nodes) or distant failure (metastasis and/or nonregional lymph nodes).

RESULTS

During a median follow-up period of 46 months, disease failure was observed in 8 patients (40%). The 3‑year progression-free survival (PFS) and overall survival (OS) rates were 62.5 and 83.0%, respectively. The failure patterns were local (n = 6, 30%), regional (n = 3, 15%) and distant (n = 4, 20%). Among patients with local failure, all failures occurred within the radiation fields (100%). Univariate analysis showed that bilateral regional lymph node involvement (p = 0.0002), initial circulating EBV viral load ≥ 3.5 log (p = 0.03) and no negativation of EBV PCR after induction CT (p = 0.0497) were independent predictors of PFS.

CONCLUSION

Patients with bilateral lymph node involvement and/or high EBV viral load have a significant recurrence rate despite multimodal therapy. These results need to be confirmed by larger studies. Given the high rate of local recurrence within radiotherapy fields, the value of dose escalation should be considered. Patients at risk of relapse should be included in dedicated trials.

A Rare Case of Extranodal Natural Killer/T-cell Lymphoma, Nasal Type Associated With Hemophagocytic Lymphohistiocytosis in a Patient With Recurrent Sinusitis

We present a rare case of hemophagocytic lymphohistiocytosis (HLH) secondary to nasal-type extranodal natural killer/T-cell lymphoma (ENKL). Nasal-type ENKL is a rare subtype of non-Hodgkin's lymphoma usually associated with Epstein-Barr virus (EBV). The patient was a 19-year-old woman who presented with facial numbness, diminished hearing, and dysgeusia. She was febrile with palatal necrosis, loss of gag reflex, and cranial nerve palsies. Labs revealed neutropenia. Broad-spectrum antimicrobials, including amphotericin, were started. Given concern for invasive fungal disease, she underwent surgical debridement, which revealed inflamed fibrous tissue and extensive necrosis. Pathology showed no fungal elements or malignancy. Lack of clinical improvement and worsening palatal necrosis prompted additional debridement. Histology identified an atypical CD3+/CD56+ cellular infiltrate. Bone marrow biopsy showed prominent hemophagocytosis, but no malignancy. She met the criteria for HLH and high-dose dexamethasone was started. Her fevers resolved. Additional labs and nasal tissue sampling with EBV-encoded RNA staining were recommended. Flow cytometry was negative, but histology revealed ENKL nasal-type, with positive EBV-encoded RNA in situ hybridization. Plasma EBV DNA level was 11,518 IU/mL. The M-SMILE (dexamethasone, methotrexate, ifosfamide, l-asparaginase, and etoposide) regimen was initiated; one cycle led to marked improvement. EBV level returned to zero. Subsequent radiation and chemotherapy, followed by autologous stem cell transplant consolidation, led to complete remission. We conclude that ENKL may mimic invasive sinusitis clinically. Fibrinoid necrosis in vessels and surrounding tissues often leads to diagnostic delay. It is important to have a high degree of clinical suspicion for malignancy in cases of HLH and sinusitis unresponsive to appropriate therapy. Obtaining proper tissue, communication with the pathologist, and prompt initiation of therapy are crucial.

Initial diagnosis of extranodal NK/T-cell lymphoma in pericardial fluid with concomitant hemophagocytic lymphohistiocytosis (HLH)

Extranasal natural killer/T-cell lymphoma arising in the heart is rare and typically presents with non-specific clinical symptoms, necessitating a biopsy for a definitive diagnosis. We report an unusual case of a 48-year-old male who initially presented with chest pain and shortness of breath. Subsequent diagnosis via pericardial fluid analysis, including flow cytometry and immunohistochemical stains, revealed extranasal NK/T-cell lymphoma without sinonasal involvement. The analysis identified neoplastic lymphoid cells expressing CD2, cytoplasmic CD3, Epstein-Barr virus, and CD56 and exhibiting increased Ki-67 staining. Additionally, the patient developed hemophagocytosis lymphocytosis secondary to NK/T cell lymphoma. Treatment included an interleukin-1 receptor antagonist (anakinra), dexamethasone, rituximab, and etoposide. Unfortunately, the patient's condition rapidly deteriorated, leading to multiorgan failure and eventual demise. Given the rarity of this lymphoma, early diagnosis based on a high suspicion level provides the best chance for improved overall survival.

Outcomes and prognostic factors of patients with Extranodal NK T cell lymphoma (ENKTL)

The staging, prognostication, and treatment of ENKTL has evolved over the years with better understanding of the disease biology. There is significant heterogeneity in the treatment followed across the world. Literature from India have been few with small number of patients. We studied the outcomes and prognostic factors of patients with ENKTL treated between May 2010 and December 2021 at our center. A total of 78 patients diagnosed with ENKTL were treated at our center. L-asparaginase based chemotherapy was administered in 84% of the patients. Close to 2/3rd patients received SMILE chemotherapy. After a median follow-up of 30 months (18.5-41.4 months), the median relapse free survival and overall survival for the overall population was 45 months (12-118 months) and 45 months (14-118 months) respectively. By multivariate analysis, PINK score of 2-4, non-receipt of RT and non-achievement of CR were associated with poor survival.

Targeted therapy with nanatinostat and valganciclovir in recurrent EBV-positive lymphoid malignancies: a phase 1b/2 study

Lymphomas are not infrequently associated with the Epstein-Barr virus (EBV), and EBV positivity is linked to worse outcomes in several subtypes. Nanatinostat is a class-I selective oral histone deacetylase inhibitor that induces the expression of lytic EBV BGLF4 protein kinase in EBV+ tumor cells, activating ganciclovir via phosphorylation, resulting in tumor cell apoptosis. This phase 1b/2 study investigated the combination of nanatinostat with valganciclovir in patients aged ≥18 years with EBV+ lymphomas relapsed/refractory to ≥1 prior systemic therapy with no viable curative treatment options. In the phase 1b part, 25 patients were enrolled into 5 dose escalation cohorts to determine the recommended phase 2 dose (RP2D) for phase 2 expansion. Phase 2 patients (n = 30) received RP2D (nanatinostat 20 mg daily, 4 days per week with valganciclovir 900 mg orally daily) for 28-day cycles. The primary end points were safety, RP2D determination (phase 1b), and overall response rate (ORR; phase 2). Overall, 55 patients were enrolled (B-non-Hodgkin lymphoma [B-NHL], [n = 10]; angioimmunoblastic T-cell lymphoma-NHL, [n = 21]; classical Hodgkin lymphoma, [n = 11]; and immunodeficiency-associated lymphoproliferative disorders, [n = 13]). The ORR was 40% in 43 evaluable patients (complete response rate [CRR], 19% [n = 8]) with a median duration of response of 10.4 months. For angioimmunoblastic T-cell lymphoma-NHL (n = 15; all refractory to the last prior therapy), the ORR/CRR ratio was 60%/27%. The most common adverse events were nausea (38% any grade) and cytopenia (grade 3/4 neutropenia [29%], thrombocytopenia [20%], and anemia [20%]). This novel oral regimen provided encouraging efficacy across several EBV+ lymphoma subtypes and warrants further evaluation; a confirmatory phase 2 study (NCT05011058) is underway. This phase 1b/2 study is registered at www.clinicaltrials.gov as #NCT03397706.

HTLV-1 cell-free DNA in plasma as a potential biomarker in HTLV-1 carriers and adult T-cell leukemia-lymphoma

Viral cell-free DNA (cfDNA) in plasma has been widely evaluated for detecting cancer and monitoring disease in virus-associated tumors. We investigated whether the amount of cfDNA of human T-cell leukemia virus type 1 (HTLV-1) correlates with disease state in adult T-cell leukemia-lymphoma (ATL). HTLV-1 cfDNA in aggressive ATL was significantly higher than that in indolent ATL and asymptomatic carriers. Notably, patients with lymphoma type represented higher HTLV-1 cfDNA amount than chronic and smoldering subtypes, though they had no abnormal lymphocytes in the peripheral blood. HTLV-1 cfDNA can be a universal biomarker that reflects the expansion of ATL clones.

Extranodal NK-/T-cell lymphoma, nasal type: what advances have been made in the last decade?

Extranodal NK-/T-cell lymphoma (ENKTCL) is a rare and highly aggressive malignancy with significant racial and geographic variations worldwide. In addition to the formerly "nasal-type" initial description, these lymphomas are predominantly extranodal in origin and typically cause vascular damage and tissue destruction, and although not fully understood, Epstein-Barr virus (EBV) has an important role in its pathogenesis. Initial assessment must include a hematopathology review of representative and viable tumor areas without necrosis for adequate immunohistochemistry studies, including EBV-encoded small RNA (EBER) in situ hybridization (ISH). Positron emission tomography with 18-fluorodeoxyglucose (¹⁸F-FDG-PET/CT) for accurate staging is essential, and most patients will have localized disease (IE/IIE) at diagnosis. Apart from other T-cell malignancies, the best treatment even for localized cases is combined modality therapy (chemotherapy plus radiotherapy) with non-anthracycline-based regimens. For advanced-stage disease, l-asparaginase-containing regimens have shown improved survival, but relapsed and refractory cases have very poor outcomes. Nowadays, even with a better understanding of pathogenic pathways, up-front therapy is completely based on chemotherapy and radiotherapy, and treatment-related mortality is not low. Future strategies targeting signaling pathways and immunotherapy are evolving, but we need to better identify those patients with dismal outcomes in a pre-emptive way. Given the rarity of the disease, international collaborations are urgently needed, and clinical trials are the way to change the future.

Epstein‒Barr virus-associated cellular immunotherapy

Epstein‒Barr virus (EBV) is a human herpes virus that is saliva-transmissible and universally asymptomatic. It has been confirmed that more than 90% of the population is latently infected with EBV for life. EBV can cause a variety of related cancers, such as nasopharyngeal carcinoma, diffuse large B-cell lymphoma, and Burkitt lymphoma. Currently, many clinical studies have demonstrated that EBV-specific cytotoxic T lymphocytes and other cell therapies can be safely and effectively transfused to prevent and treat some diseases caused by EBV. This review will mainly focus on discussing EBV-specific cytotoxic T lymphocytes and will touch on therapeutic EBV vaccines and chimeric antigen receptor T-cell therapy briefly.

Virological Markers in Epstein–Barr Virus-Associated Diseases

Epstein–Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world’s population. After primary infection—responsible for infectious mononucleosis in young adults—the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

Expression of soluble CD27 in extranodal natural killer/T-cell lymphoma, nasal type: potential as a biomarker for diagnosis and CD27/CD70-targeted therapy

The engagement of CD27 on lymphocytes with its ligand, CD70, on tumors is believed to mediate tumor immune evasion and the elevation of serum soluble CD27 (sCD27) levels in patients with CD70-positive malignancies. We previously showed that CD70 is expressed in extranodal natural killer/T-cell lymphoma, nasal type (ENKL), an Epstein-Barr virus (EBV)-related malignancy. However, little is known about serum sCD27 expression and its association with the clinical characteristics of, and the CD27/CD70 interaction in, ENKL. In the present study, we show that serum sCD27 is significantly elevated in the sera of patients with ENKL. The levels of serum sCD27 provided excellent diagnostic accuracy for discriminating patients with ENKL from healthy subjects, correlated positively with the levels of other diagnostic markers (lactate dehydrogenase, soluble interleukin-2 receptor, and EBV-DNA), and decreased significantly following treatment. Elevated serum sCD27 levels also correlated significantly with advanced clinical stage and tended to correspond with shorter survival, in patients with ENKL. Immunohistochemistry indicated that CD27-positive tumor-infiltrating immune cells exist adjacent to CD70-positive lymphoma cells. In addition, serum sCD27 levels in patients with CD70-positive ENKL were significantly higher than those in patients with CD70-negative ENKL, suggesting that the intra-tumoral CD27/CD70 interaction boosts the release of sCD27 in serum. Furthermore, the EBV-encoded oncoprotein latent membrane protein 1 upregulated CD70 expression in ENKL cells. Our results suggest that sCD27 may serve as a novel diagnostic biomarker and also may serve as a tool for evaluating the applicability of CD27/CD70-targeted therapies by predicting intra-tumoral CD70 expression and CD27/CD70 interaction in ENKL.

Diagnostic performance and prognostic value of circulating tumor DNA methylation marker in extranodal natural killer/T cell lymphoma

Circulating tumor DNA (ctDNA) carries tumor-specific genetic and epigenetic variations. To identify extranodal natural killer/T cell lymphoma (ENKTL)-specific methylation markers and establish a diagnostic and prognosis prediction model for ENKTL, we describe the ENKTL-specific ctDNA methylation patterns by analyzing the methylation profiles of ENKTL plasma samples. We construct a diagnostic prediction model based on ctDNA methylation markers with both high specificity and sensitivity and close relevance to tumor staging and therapeutic response. Subsequently, we built a prognostic prediction model showing excellent performance, and its predictive accuracy is significantly better than the Ann Arbor staging and prognostic index of natural killer lymphoma (PINK) risk system. Notably, we further establish a PINK-C risk grading system to select individualized treatment for patients with different prognostic risks. In conclusion, these results suggest that ctDNA methylation markers are of great value in diagnosis, monitoring, and prognosis, which might have implications for clinical decision-making of patients with ENKTL.

In-depth circulating tumor DNA sequencing for prognostication and monitoring in natural killer/T-cell lymphomas

Background

Epstein-Barr virus (EBV) quantitation and current imaging modalities are used for diagnosis and disease monitoring in Extranodal NK/T cell lymphoma (ENKTL) but have limitations. Thus, we explored the utility of circulating tumor DNA (ctDNA) as a diagnostic biomarker.

Methods

Through in-depth sequencing of 118 blood samples collected longitudinally at different time points from 45 patients, we examined the mutational profile of each sample, estimated its impact on the clinical outcome, and assessed its role as a biomarker in comparison with EBV DNA quantitation.

Results

The ctDNA concentration was correlated with treatment response, stage, and EBV DNA quantitation. The detection rate of ctDNA mutation was 54.5%, with BCOR (21%) being the most commonly mutated gene in newly diagnosed patients; TP53 mutation (33%) was the most prevalent in patients that experienced a relapse. Additionally, patients in complete remission exhibited a rapid clearance of ENKTL-related somatic mutations, while relapsed patients frequently presented with persisting or emerging mutations. We detected ctDNA mutations in EBV-negative patients (50%) and mutation clearance in EBV-positive patients in remission, suggesting ctDNA genotyping as an efficient complementary monitoring method for ENKTL. Additionally, mutated DDX3X (PFS HR, 8.26) in initial samples predicted poor outcome.

Conclusion

Our results suggest that ctDNA analysis can be used to genotype at diagnosis and estimate the tumor burden in patients with ENKTL. Furthermore, ctDNA dynamics indicate the potential use of testing it to monitor therapeutic responses and develop new biomarkers for precision ENKTL therapy.

Molecular Monitoring of Lymphomas

Molecular monitoring of tumor-derived alterations has an established role in the surveillance of leukemias, and emerging nucleic acid sequencing technologies are likely to similarly transform the clinical management of lymphomas. Lymphomas are well suited for molecular surveillance due to relatively high cell-free DNA and circulating tumor DNA concentrations, high somatic mutational burden, and the existence of stereotyped variants enabling focused interrogation of recurrently altered regions. Here, we review the clinical scenarios and key technologies applicable for the molecular monitoring of lymphomas, summarizing current evidence in the literature regarding molecular subtyping and classification, evaluation of treatment response, the surveillance of active cellular therapies, and emerging clinical trial strategies.

Plasma EBV-DNA and peripheral blood mononuclear cell EBV-DNA have disparate clinical relevance in patients with extranodal NK/T-cell lymphoma

BACKGROUND

Extranodal NK/T-cell lymphoma (ENKTCL) is an Epstein-Barr virus (EBV)-related hematological malignancy. The presence of EBV-DNA in peripheral blood is a widely used ENKTCL tumor marker. However, there is no consensus on the preferred blood specimen type for EBV testing. Furthermore, discordance between EBV-based and imaging-based disease assessments is common, and how to interpret this discordance is important.

METHOD

We retrospectively analyzed the data of ENKTCL patients in the Affiliated Cancer Hospital of Zhengzhou university and Sun Yat-sen University Cancer Center. All EBV-DNA and imaging-based disease assessment data were collected at diagnosis, during treatment, at the end of treatment, and during follow-up. We compared matched plasma EBV-DNA and peripheral blood mononuclear cell (PBMC) EBV-DNA and matched EBV-based and imaging-based assessments to uncover their clinical relevance.

RESULT

A total of 450 patients with adequate data were included, of whom 278 had plasma EBV-DNA data, 250 had PBMC EBV-DNA data, and 78 had matched plasma and PBMC EBV-DNA data. No significant correlations were found between PBMC and plasma EBV-DNA and between PBMC EBV-DNA and imaging-based assessment, but patients with positive PBMC EBV-DNA at diagnosis or intermittently/persistently positive PBMC EBV-DNA during follow-up had poorer survival. In contrast, plasma EBV-DNA strongly correlated with lymphoma status. Detectable pre- and post-treatment plasma EBV-DNA was associated with significantly worse survival. Patients with early-stage disease who had detectable plasma EBV-DNA at the end of treatment shared similar survival to those with advanced-stage disease, even if their imaging-based assessments were negative. For disease relapse monitoring, 78 (55.7%) episodes of relapse were detected by both imaging and plasma EBV-DNA; 58 (41.4%) detected by plasma EBV-DNA earlier than imaging, with a median time of 9.3 (0.3 - 37.8) months; and only 4 (2.9%) detected by plasma EBV-DNA later than imaging. The sensitivities of plasma EBV-DNA, PET/CT, and CT/MRI were 97.1%, 76.8%, and 45.1%, respectively, and their specificities were 91.7%, 84.2%, and 96.7%, respectively. Analysis of EBV kinetic patterns in EBV+/imaging- episodes revealed that relapse occurred only in patients with intermittently/persistently positive plasma EBV-DNA. Persistent plasma EBV+ was also seen in patients after autologous hematopoietic stem cell transplantation. Occasional EBV+ was not associated with relapse.

CONCLUSION

Plasma and PBMC EBV-DNA have different clinical relevance in ENKTCL patients. PBMC EBV-DNA does not correlate with imaging-based disease assessment. PBMC or even whole blood should not be used for response evaluation and relapse monitoring. However, PBMC EBV-DNA still has prognostic value. Plasma EBV-DNA is strongly related to tumor status and is not only a prognosticator at diagnosis and end of treatment, but also a sensitive marker in relapse monitoring compared to PET/CT and CT/MRI. The specificity of plasma EBV-DNA is relatively low, but when EBV-DNA kinetic patterns are considered, it can identify at-risk patients.

Nomograms to predict progression of disease within 24 months in patients with localized natural killer/T-cell lymphoma

Aims: Progression of disease within 24 months (POD24) is associated with poor survival in some subtypes of lymphoma.The aim is to identify high-risk patients with localized extranodal natural killer/T-cell lymphoma (ENKTL) and to define clinical factors associated with the risk of early recurrence after antitumor treatment. Methods: The authors retrospectively analyzed 330 cases with localized ENKTL, of which 89 experienced POD24. Results: The 5-year overall survival of the POD24 group was extremely inferior to that of the non-POD24 group. Risk factors for POD24 were Eastern Cooperative Oncology Group performance status ≥2, response evaluation (non-complete remission) after first-line treatment and elevated lactate dehydrogenase concentrations. Also, higher Epstein-Barr virus DNA titer was related to POD24. Based on these data with or without the availability of Epstein-Barr virus DNA, the authors conducted two nomograms to predict POD24, which showed good accuracy with high C statistics. Conclusion: The results showed that POD24 could serve as a marker to identify patients whose medical needs were unmet in ENKTL.

A retrospective analysis of EBV-DNA status with the prognosis of lymphoma

Epstein–Barr virus (EBV) infection is proved to be associated with clinicopathology of lymphoma. However, little is known about the relationship between EBV‐DNA status after treatment and prognosis. In this study, real‐time polymerase chain reaction (PCR) was used for quantitative detection of EBV‐DNA load in peripheral blood of all 26,527 patients with lymphoma, and the clinical characteristics and prognosis of 202 patients were retrospectively analysed, including 100 patients with positive EBV‐DNA and 102 randomly selected patients with negative EBV‐DNA. We found that the average rate of EBV‐DNA positivity in lymphomas was 0.376%, and EBV‐DNA‐positive patients presented higher risk with elevated lactate dehydrogenase (LDH) and β2‐MG level, B symptoms, secondary hemophagocytic syndrome and lower objective response rate compared to EBV‐DNA‐negative patients. Multivariate analysis revealed EBV‐DNA‐positive patients had inferior progression‐free survival (PFS) and overall survival (OS) and EBV‐DNA level before treatment was related to PFS but not OS of T/NK cell lymphoma. In T/NK cell lymphoma, EBV‐DNA converting negative after treatment was correlated with better PFS but not OS, and second‐line therapy could induce more EBV‐DNA‐negative conversion compared to CHOP‐based therapy. In all, EBV‐DNA positivity before treatment can be a biomarker representing the tumour burden and an independent prognostic factor. EBV‐DNA‐negative conversion after treatment is a good prognostic factor for T/NK cell lymphomas.

The clinical characteristics and prognostic factors of 410 patients with natural killer/T-cell lymphoma

PURPOSE

To investigate the clinical characteristics and prognostic factors of natural killer/T-cell lymphoma (NKTCL).

METHODS

We retrospectively reviewed 410 NKTCL patients admitted to our lymphoma center from 2000 to 2019. Overall survival (OS) and progression-free survival (PFS) were estimated with the Kaplan-Meier method, and the differences between the study groups were compared by the log-rank test.

RESULTS

The median age of the 410 patients was 44 (range 8-84), and the 5-year OS and PFS were 61.2% and 38.4%, respectively. For patients with stage I/II, the 5-year PFS rate was 57.5%, and the 5-year OS rate was 77.2%. For patients with stage III/IV, the 5-year PFS rate was 17.4%, and the 5-year OS rate was 43.7%. Compared to the patients who received radiotherapy alone or chemotherapy alone as their initial treatment, the patients who received combined chemoradiotherapy had longer PFS (P = 0.013). Independent prognostic factors for OS were stage III/IV (P = 0.001), elevated IPI/aaIPI score (P = 0.019), elevated PINK score (P < 0.001) and elevated plasma EBV-DNA (P = 0.003). An elevated PINK score (P < 0.001) was an independent prognostic factor for PFS.

CONCLUSION

Stage III/IV, elevated IPI/aaIPI score, elevated PINK score and elevated plasma EBV-DNA were independent prognostic factors for OS. Elevated PINK score was an independent prognostic factor for PFS. In stage III/IV patients, the patients who received combined chemoradiotherapy had significantly longer PFS.

The Outcome of Induction Therapy for EBV-Related Hemophagocytic Lymphohistiocytosis: A Model for Risk Stratification

Background

Epstein–Barr virus (EBV)–related hemophagocytic lymphohistiocytosis (HLH) is an abnormal inflammation caused by EBV infection, which has high mortality during induction therapy.

Objectives

This study is aimed to build a model to predict the risk of death during induction therapy.

Methods

The patients with EBV-HLH admitted from January 2015 to December 2018 were retrospectively reviewed. The primary outcome was death during induction therapy. The interval from receiving therapy to death or the end of induction therapy was the observing time. The patients admitted from January 2015 to December 2017 were assigned to the primary group, and the patients admitted from January to December 2018 were assigned to the validation group.

Results

We included 234 patients with EBV-HLH, of whom 65 (27.4%) died during induction therapy. The middle observing time was 25 days. On the basis of the primary group, the multivariate Cox analysis demonstrated age &gt;18 years, blood urea nitrogen, procalcitonin &gt;2 µg/L, serum CD25, and EBV-DNA in peripheral blood mononuclear cell as the risk factors of death during induction therapy. We developed a nomogram integrating the above factors with high predictive accuracy (c-statistic, 0.86) and stratified all patients into the high-risk and the low-risk groups. On the basis of the validation group, the high-risk patients had a higher risk of death (hazard ratio, 4.93; P = 0.012). In the subgroup analysis based on patients receiving etoposide-based strategy, the mortality in high-risk and low-risk patients was 43.9 and 3.1 per 100 person-weeks, respectively.

Conclusion

We developed a nomogram for risk stratification of patients with EBV-HLH receiving induction therapy.

A genomic-augmented multivariate prognostic model for the survival of Natural-killer/T-cell lymphoma patients from an international cohort

With lowering costs of sequencing and genetic profiling techniques, genetic drivers can now be detected readily in tumors but current prognostic models for Natural-killer/T cell lymphoma (NKTCL) have yet to fully leverage on them for prognosticating patients. Here, we used next-generation sequencing to sequence 260 NKTCL tumors, and trained a genomic prognostic model (GPM) with the genomic mutations and survival data from this retrospective cohort of patients using LASSO Cox regression. The GPM is defined by the mutational status of 13 prognostic genes and is weakly correlated with the risk-features in International Prognostic Index (IPI), Prognostic Index for Natural-Killer cell lymphoma (PINK) and PINK-Epstein-Barr virus (PINK-E). Cox-proportional hazard multivariate regression also showed that the new GPM is independent and significant for both progression-free survival (PFS, HR: 3.73, 95% CI 2.07-6.73; P<0.001) and overall survival (OS, HR: 5.23, 95% CI 2.57-10.65; P=0.001) with known risk-features of these indices. When we assign an additional risk-score to samples, which are mutant for the GPM, the Harrell's C-indices of GPM-augmented IPI, PINK and PINK-E improved significantly (P<0.001, χ² test) for both PFS and OS. Thus, we report on how genomic mutational information could steer towards better prognostication of NKTCL patients. This article is protected by copyright. All rights reserved.

Utility of Epstein-Barr Viral Load in Blood for Diagnosis and Predicting Prognosis of Lymphoma: A Comparison with Epstein-Barr Virus-Encoded RNA in Situ Hybridization

Epstein-Barr virus (EBV) is a ubiquitous pathogen that persists in a small portion of B cells after primary infection and is etiologically associated with multiple lymphoma subtypes. Herein, we evaluated the clinical utility of EBV real-time quantitative PCR in comparison with the widely used Epstein-Barr virus-encoded RNA (EBER) in situ hybridization (ISH) method in 912 patients with four lymphoma subtypes: diffuse large B-cell lymphoma (DLBCL), extranodal natural killer/T-cell lymphoma (ENKTCL), peripheral T-cell lymphoma (PTCL), and Hodgkin lymphoma. We also assessed the impact of EBV positivity determined from each method or a combination of both methods on mortality using Kaplan-Meier survival analysis and Cox proportional hazard regression. EBV real-time quantitative PCR identified more positive cases than EBER-ISH for all subtypes, except ENKTCL. EBV DNA-positive patients with ENKTCL and PTCL displayed poorer overall survival (OS) than EBV DNA-negative patients (P = 0.0016 and P = 0.0013, respectively). In addition, among those with EBER-positive DLBCL and ENKTL and those with EBER-negative PTCL, OS was significantly worse for EBV DNA-positive patients (P = 0.027, P = 0.0016, and P = 0.0018, respectively). EBER positivity was associated with worse OS for DLBCL (P = 0.037), in reanalyses including only the 862 patients with unambiguous EBER-ISH results. Overall, EBV DNA positivity is a more effective prognostic marker than EBER-ISH status for patients with certain lymphoma subtypes.

Extranodal Natural Killer/T-Cell Lymphomas: Current Approaches and Future Directions

Extranodal natural killer/T(NK/T)-cell lymphoma (ENKTL) is a rare subtype of non-Hodgkin lymphoma that typically presents with an isolated nasal mass, but a sizeable minority present with advanced stage disease and have a significantly poorer prognosis. Those with limited disease are standardly treated with chemotherapy and radiation while those with advanced stage disease are treated with L-asparaginase containing chemotherapy regimens. The addition of modern radiation therapy techniques and the incorporation of L-asparaginase into chemotherapy regimens have significantly improved outcomes in this disease, but relapses and death from relapsed disease remain frequent. Given the high rate of relapse, several novel therapies have been evaluated for the treatment of this disease. In this review, we explore the current standard of care for ENKTL as well as novel therapies that have been evaluated for its treatment and the biologic understanding behind these therapies.

The superiority of Epstein-Barr virus DNA in plasma over in peripheral blood mononuclear cells for monitoring EBV-positive NK-cell lymphoproliferative diseases

Epstein-Barr virus (EBV), characterized as an omnipresent virus, has been found able to infect NK cells and leads to NK-cell type EBV-positive lymphoproliferative diseases (EBV-NK-LPDs). We retrospective analysed 202 EBV-NK-LPDs (including 64 CAEBV-NK, 27 ANKL, and 111 ENKTL) patients' relationships between EBV DNA copies laboratory test results and clinical features. In CAEBV-NK cohort, EBV DNA loads in either plasma or PBMCs had significant differences between the active state and the inactive state. Receiver operating characteristic (ROC) curves were used to measure the diagnosis accuracy of EBV DNA copies. After comparing the area under the curve (AUC), EBV DNA loads in plasma had significantly higher accuracy in distinguishing disease activation than in PBMCs. Therefore, we propose redefining CAEBV-NK diagnosis criteria as increased EBV DNA copies in plasma (over 7.1×10² copies/ml) instead of in peripheral blood. In ANKL and ENKTL cohorts, patients who received effective therapy had significantly lower EBV DNA copies in plasma & PBMCs than in those with ineffective therapy. The significant and consistent decline indicated EBV DNA loads in plasma being a more sensitive biomarker in monitoring EBV-NK-LPDs therapy responses. Hemophagocytic lymphohistiocytosis (HLH) can occur secondary to EBV-NK-LPDs, mostly associated with a poor prognosis, so we try to estimate the combination of HLH by monitoring EBV DNA copies. When comparing the ROC curves of EBV DNA copies, EBV DNA loads in plasma had higher diagnosis accuracy. When the copies level over 4.16×10³ copies/ml, it might indicate combining with HLH. This article is protected by copyright. All rights reserved.

[More than a Harmless Cold]

More than a Harmless Cold Abstract. We report on a 54-year-old patient who presented to the general practitioner several times due to a cold with a runny nose and a headache. Despite various therapies the symptoms didn't subside. Further examination showed a nasal NK/T-cell lymphoma stage IV. The patient died despite intensive therapy.

Sequential P-GEMOX and radiotherapy for early-stage extranodal natural killer/T-cell lymphoma: A multicenter study

Extranodal natural killer/T-cell lymphoma, nasal-type (ENKTL) is a distinct subtype of non-Hodgkin lymphoma and most of the patients presented localized disease. Combined modality therapy (CMT), namely chemotherapy combined with radiotherapy, has been recommended for patients with early-stage ENKTL. However, the optimal CMT has not been fully clarified. This study reports the efficacy and toxicity of sequential P-GEMOX (pegaspargase, gemcitabine and oxaliplatin) and radiotherapy in a large Chinese cohort comprising of 202 patients diagnosed with early-stage ENKTL from six medical centers. The observed best overall response rate was 96.0% and 168 (83.2%) patients achieved complete remission. With a median follow-up of 44.1 months, the 3-year progression-free survival (PFS) and overall survival (OS) were 74.6% and 85.2%, respectively. Multivariate analysis suggested that extensive primary tumor (PFS, hazard ratio [HR] 3.660, 95% CI 1.820-7.359, p <  0.001; OS, HR 3.825, 95% CI 1.442-10.148, p = 0.007) and Eastern Cooperative Oncology Group performance status ≥ 2 (PFS, 3.042, 95% CI 1.468-6.306, p = 0.003; OS, HR 3.983, 95% CI 1.678-9.457, p = 0.02) were independent prognostic factors for survival outcomes. Among the established prognostic models for ENKTL, the nomogram-revised risk index model had optimal prognostic risk stratification ability (PFS, p < 0.001; OS, p < 0.001) and relatively balanced population distribution. The adverse events of this CMT were well-tolerated and manageable. In conclusion, sequential P-GEMOX and radiotherapy showed favorable efficacy with acceptable toxicity, and could be an effective treatment option for early-stage ENKTL patients.

Disparity analysis and prognostic value of pretreatment whole blood Epstein-Barr virus DNA load and Epstein-Barr encoding region status in lymphomas: A retrospective multicenter study in Huaihai Lymphoma Working Group

Elevated Epstein-Barr virus (EBV) DNA load is common in lymphomas. However, it remains unclear whether the disparity in viral load and its prognostic value in lymphomas are correlated with Epstein-Barr encoding region (EBER) status. In this retrospective multicenter study, we collected the data of pretreatment whole blood EBV DNA (pre-EBV DNA) and EBER status and evaluated their disparity and prognostic values in lymphomas. A total of 454 lymphoma patients from December 2014 to August 2020 were retrospectively retrieved. Mann-Whitney U test, Kruskal-Wallis test and Bonferroni's adjustment were used to explore the disparity of EBV DNA and EBER status in lymphomas. Time-dependent receiver operating characteristic analysis and MaxStat analysis were used to determine optimal cutoff points of pre-EBV DNA load. Univariable and multivariable Cox proportional hazards models were established for the estimation of prognostic factors. The positive rate of EBV DNA in natural killer T-cell lymphoma (NKTL) patients was higher than that in diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Hodgkin lymphoma (HL) patients, and the median positive pre-EBV copy number of NKTL was also higher than that of FL and DLBCL. EBV DNA could clearly distinguish the prognosis of DLBCL, NKTL, HL and peripheral T-cell lymphoma, and the integration of EBER status and EBV DNA could differentiate the prognosis of HL patients. Multivariable results revealed that pre-EBV DNA load had an effect on the prognosis of NKTL, FL and DLBCL. The status of pre-EBV DNA and EBER were disparate. Whole blood pre-EBV DNA predicted the prognosis of lymphomas, and the combination of EBV and EBER status could differentiate the prognosis of HL.

How to Identify Patients at High Risk of Developing Nasal-Type, Extranodal Nature Killer/T-Cell Lymphoma-Associated Hemophagocytic Syndrome

Nasal-type, extranodal nature killer (NK)/T-cell lymphoma-associated hemophagocytic syndrome (NK/T-LAHS) is a rare and life-threatening disease, requiring investigation of risk stratification. We conducted a retrospective study and proposed nomograms to predict NK/T-LAHS. The discriminative ability and calibration of the nomograms for prediction were tested using C statistics and calibration plots. We analyzed 533 patients with extranodal NK/T-cell lymphoma (ENKTL), out of which 71 were diagnosed with hemophagocytic syndrome (HPS), with a cumulative incidence of 13.3%. Significant difference for 2-year survival was found between patients with and without HPS (14.7% vs. 77.5%). Analyses showed that Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2, B symptoms, and bone marrow (BM) invasion were significantly associated with NK/T-LAHS. We used these data as the basis to establish a nomogram of risk index for ENKTL (RINK). In 335 patients with available data for Epstein-Barr virus DNA (EBV-DNA), we found high viral copies (≥4,450 copies/ml) were correlated with NK/T-LAHS. When these data were added to RINK, we developed another nomogram that included EBV-DNA data (RINK-E). The nomograms displayed good accuracy in predicting NK/T-LAHS with a C-statistics of 0.919 for RINK and a C-statistics of 0.946 for RINK-E, respectively. The calibration chart also showed an excellent consistency between the predicted and observed probabilities. The proposed nomograms provided individualized risk estimate of HPS in patients with ENKTL.

Towards Next Generation Biomarkers in Natural Killer/T-Cell Lymphoma

Natural killer/T-cell lymphoma (NKTCL) is an Epstein-Barr virus-associated non-Hodgkin lymphoma linked to an aggressive clinical course and poor prognosis. Despite an improvement in survival outcomes with the incorporation of novel agents including immune checkpoint inhibitors in the treatment of NKTCL, a significant proportion of patients still relapse or remain refractory to treatment. Several clinical prognostic models have been developed for NKTCL patients treated in the modern era, though the optimal approach to risk stratification remains to be determined. Novel molecular biomarkers derived from multi-omic profiling have recently been developed, with the potential to improve diagnosis, prognostication and treatment of this disease. Notably, a number of potential biomarkers have emerged from a better understanding of the tumor immune microenvironment and inflammatory responses. This includes a recently described 3'UTR structural variant in the PD-L1 gene, which confers susceptibility to checkpoint immunotherapy. In this review, we summarize the biomarker landscape of NKTCL and highlight emerging biomarkers with the potential for clinical implementation.

Extranodal NK/T-Cell Lymphoma, Nasal Type: Genetic, Biologic, and Clinical Aspects with a Central Focus on Epstein-Barr Virus Relation

Extranodal NK/T-Cell Lymphoma, nasal type (ENKTL-NT) has some salient aspects. The lymphoma is commonly seen in Eastern Asia, has progressive necrotic lesions in the nasal cavity, makes midfacial destructive lesions, and shows poor prognosis. The lymphoma cell is originated from either NK- or γδ T-cells, which express CD56. Since the authors first demonstrated the existence of Epstein–Barr virus (EBV) DNA and EBV oncogenic proteins in lymphoma cells, ENKTL-NT has been recognized as an EBV-associated malignancy. Because the angiocentric and polymorphous lymphoma cells are mixed with inflammatory cells on a necrotic background, the diagnosis of ENKTL-NT requires CD56 immunostaining and EBER in situ hybridization. In addition, serum the EBV DNA level is useful for the diagnosis and monitoring of ENKTL-NT. Although ENKTL-NT is refractory lymphoma, the prognosis is improved by the development of therapies such as concomitant chemoradiotherapy. The basic research reveals that a wide variety of intracellular/cell surface molecules, cytokines, chemokines, and micro RNAs are involved in lymphomagenesis, and some of them are related to EBV. Understanding lymphoma behavior introduces new therapeutic strategies, such as the usage of immune checkpoint inhibitors, peptide vaccines, and molecular targeting therapy. This review addresses recent advances in basic and clinical aspects of ENKTL-NT, especially its relation to EBV features.

Virus-Associated Biomarkers in Oropharyngeal and Nasopharyngeal Cancers and Recurrent Respiratory Papillomatosis

Nasopharyngeal cancer (NPC) is known to be associated with Epstein–Barr virus (EBV). Pre-treatment and post-treatment detection of plasma cell-free EBV DNA has been shown to be useful as a diagnostic as well as a prognostic factor in NPC. On the other hand, the incidence of human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) is increasing. In contrast to cervical cancer, which is classically known to be an HPV-associated malignancy, HPV testing is not clinically applied for OPC, except for p16 immunostaining as a surrogate marker of HPV infection. One of the major characteristics of HPV-associated OPC is its association with a good prognosis compared with non-HPV-associated OPC. However, some patients still have a poor prognosis. Another characteristic of HPV-associated OPC is the distinct risk factor of high sexual activity. Establishing a biomarker for the prediction of the prognosis before and/or after initial treatment, as well as for diagnosis in populations at high risk, is of marked interest. With this background, HPV DNA detection in plasma and oral rinses has become an area of focus. In this review, the current significance of HPV DNA detection in plasma and oral rinse samples, as well as serum HPV antibody levels, is evaluated.

Nasal-type extranodal NK/T-cell lymphoma presenting as recurrent periorbital cellulitis

Nasal-type extranodal natural killer/T-cell lymphoma (ENKTCL) is a rare disease with a poor prognosis. It has features similar to other granulomatous and infectious diseases of the nose and paranasal sinuses, which can make diagnosis challenging and delayed. We present a case of 38-year-old man who was admitted to the hospital on three occasions over a 3-month period for right periorbital erythema, nasal congestion and discharge. Following two separate surgical debridement and biopsies, ENKTCL was diagnosed and the patient was commenced on chemoradiotherapy. The case highlights the atypical nature of his presentation and the high degree of suspicion for a pathological process that must be maintained to formulate the diagnosis.

Assessment of the prognostic value of interim fluorodeoxyglucose positron emission tomography/computed tomography in nasal-type extranodal natural killer/T-cell lymphoma

Background

The prognostic value of interim positron emission tomography/computed tomography (PET/CT) for nasal-type extranodal natural killer/T-cell lymphoma (ENKTL) is controversial. We evaluated the prognostic value of interim PET/CT in ENKTL patients to facilitate risk stratification and guide clinical treatment.

Methods

Patients with ENKTL who received first-line chemotherapy based on L-asparaginase/pegaspargase with/without involved-field radiotherapy were recruited for this study. Pretreatment and interim PET/CT evaluations were performed. Interim PET/CT was evaluated via the maximum standardized uptake value (SUVmax) and the Deauville 5-point scale (DS); and the capacity to predict progression-free survival (PFS) and overall survival (OS) was evaluated. Receiver operating characteristic (ROC) curves were used to determine the optimal SUVmax cutoff. Fisher's exact test was used to analyze relationships between interim PET/CT results and clinical characteristics. Univariate and multivariate analyses were performed to examine the independent effects of interim PET/CT. The Cochran-Mantel-Haenszel test was used to assess the prognostic value of interim PET/CT at different timepoints.

Results

Overall, 129 ENKTL patients were enrolled. The optimal interim PET/CT SUVmax cut-off was 4.95. The median follow-up was 34 [2-90] months, in the low SUVmax group (≤4.95), the 2-year PFS and OS rates were 76.3% and 88.0%, respectively; in the high SUVmax group (>4.95), the PFS and OS rates were 15.6% and 44.5%, respectively. Likewise, for the DS 1-3 group, the PFS and OS rates were 78.9% and 91.2%, respectively; and in the DS 4 or 5 group, the rates of PFS and OS were 49.7% and 69.0%, respectively. In univariate analysis, interim PET/CT evaluation based on SUVmax and DS scores were both PFS and OS predictors. In multivariate analysis, SUVmax was independently significantly associated with PFS (P<0.001) and OS (P=0.002), and DS was independently significantly associated with PFS (P=0.004) but not OS (P=0.204). In the Cochran-Mantel-Haenszel testing, the SUVmax and DS were significantly associated with PFS and OS after adjustments for the interim PET/CT timing.

Conclusions

Interim PET/CT was of prognostic value concerning ENKTL. The SUVmax is an independent prognostic indicator of PFS and OS, while the DS is an independent prognostic indicator of PFS but not OS. The SUVmax is of greater prognostic value than DS.

Sildenafil prevents HDACi-induced Epstein-Barr virus reactivation through the PKG pathway in NK/T cell lymphoma; potential implications for HDACi-mediated fatal complications

Romidepsin, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of relapsed and refractory peripheral T-cell lymphoma. However the use of romidepsin reportedly causes potent EBV (Epstein-Barr virus) reactivation leading to severe adverse events in patients with natural killer (NK)/T-cell lymphoma (NKTL). As inhibition of EBV lytic cycle reactivation may help prevent romidepsin-induced adverse events in NKTL, we herein set out to identify a safe and effective drug for inhibiting EBV reactivation and examine its mechanism of inhibition. EBV reactivation was evaluated by qRT-PCR of BZLF1 and BRLF1 mRNA expression, qPCR of EBV DNA, and immunoblotting of viral EA-D protein. High-throughput screening of FDA-approved drugs was performed to identify safe and effective molecules and test their effect on romidepsin-induced EBV reactivation in the EBV-positive NKTL cell lines, SNK6 and NK92MI. We found that phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra; Pfizer), appeared to be nontoxic and effective inhibitors of romidepsin-induced EBV reactivation. Clinical relevance was investigated by qPCR of EBV in two primary effusion samples of NKTL patients. We also investigated the molecular consequences downstream of sildenafil-induced PDE5 inhibition in NKTL cells. A negative correlation was established between the cGMP/PKG pathway and EBV reactivation in NKTL cells. On a molecular level, PDE5 inhibition downregulates BZLF1 and BRLF1 through cGMP/PKG signaling-induced ZNF overexpression. Co-treatment with romidepsin and sildenafil (inhibiting HDAC and PDE5, respectively) showed a synergistic inhibitory effect on NKTL cells, highlighting PDE5 as an attractive target for future therapy in NKTL.

Extranodal Natural Killer/T-cell Lymphoma, Nasal Type: Diagnosis and Treatment

The aggressive lymphoma, extranodal natural killer/T-cell lymphoma-nasal type, is strongly associated with Epstein-Barr virus (EBV) and is most common in Asia and in South and Central America. By contrast, incidence is low in the United States and Europe, where extranodal natural killer/T-cell lymphoma represents only 0.2%-0.4% of all newly diagnosed non-Hodgkin lymphomas. At diagnosis, it is important to test for EBV DNA in plasma by polymerase chain reaction and to carry out positron emission tomography/computer tomography and magnetic resonance imaging of the nasopharynx. In stage I/II disease, radiotherapy is the most important treatment modality, but in high-risk stage I/II disease (stage II, age > 60 y, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group performance score ≥2, primary tumor invasion), it should be combined with chemotherapy. The most optimal responses are reached with nonmultidrug resistance-based therapy (eg, asparaginase- or platinum-based therapy). Therapeutic approaches consist of either platinum-based concurrent chemoradiotherapy or sequential chemoradiotherapy. The minimum dose of radiotherapy should be 50-56 Gy. Treatment of stage III/IV disease consists of 3 cycles of chemotherapy followed by autologous hematopoietic cell transplantation. Allogeneic hematopoietic cell transplantation should only be considered in case of relapsed disease or after difficulty reaching complete remission. During treatment and follow-up, plasma EBV levels should be monitored as a marker of tumor load.

Chronic Active Epstein-Barr Virus Infection: The Elucidation of the Pathophysiology and the Development of Therapeutic Methods

Chronic active Epstein-Barr virus infection (CAEBV) is a disease where Epstein-Barr virus (EBV)-infected T- or NK-cells are activated and proliferate clonally. The symptoms of this dual-faced disease include systemic inflammation and multiple organ failures caused by the invasion of infected cells: inflammation and neoplasm. At present, the only effective treatment strategy to eradicate EBV-infected cells is allogeneic stem cell transplantation. Lately, the investigation into the disease's pathogenic mechanism and pathophysiology has been advancing. In this review, I will evaluate the new definition in the 2017 WHO classification, present the advancements in the study of CAEBV, and unfold the future direction.

Epstein-Barr Virus-Oral Bacterial Link in the Development of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. Its development has been associated with diverse factors such as tobacco smoking and alcohol consumption. In addition, it has been suggested that microorganisms are risk factors for oral carcinogenesis. Epstein-Barr virus (EBV), which establishes lifelong persistent infections and is intermittently shed in the saliva, has been associated with several lymphomas and carcinomas that arise in the oral cavity. In particular, it has been detected in a subset of OSCCs. Moreover, its presence in patients with periodontitis has also been described. Porphyromonas gingivalis (P. gingivalis) is an oral bacterium in the development of periodontal diseases. As a keystone pathogen of periodontitis, P. gingivalis is known not only to damage local periodontal tissues but also to evade the host immune system and eventually affect systemic health. Persistent exposure to P. gingivalis promotes tumorigenic properties of oral epithelial cells, suggesting that chronic P. gingivalis infection is a potential risk factor for OSCC. Given that the oral cavity serves as the main site where EBV and P. gingivalis are harbored, and because of their oncogenic potential, we review here the current information about the participation of these microorganisms in oral carcinogenesis, describe the mechanisms by which EBV and P. gingivalis independently or synergistically can collaborate, and propose a model of interaction between both microorganisms.

Durable Response to Sintilimab and Chidamide in a Patient With Pegaspargase- and Immunotherapy-Resistant NK/T-Cell Lymphoma: Case Report and Literature Review

The prognosis of patients with relapsed/refractory NK/T-cell lymphoma (NKTCL) is dismal. Immunotherapy has showed encouraging anti-tumor activity in patients with asparaginase-resistant NKTCL; however, only a portion of patients benefit and the median response duration is rather short. Treatment strategies have not been identified for immunotherapy-resistant NKTCL. We describe a patient with primary cutaneous NKTCL experienced disease progression after pegaspargase-based chemotherapy and PD-1 inhibitor (sintilimab)-based immunotherapy. Following a combined treatment of sintilimab and the HDAC inhibitor chidamide, the patient achieved a durable complete molecular response with mild toxicity. This case indicates that the combination of PD-1 inhibitor and HDAC inhibitor might be a treatment choice for immunotherapy-resistant NKTCL.

Superiority of Epstein-Barr Virus DNA in the Plasma Over Whole Blood for Prognostication of Extranodal NK/T Cell Lymphoma

Background

Extranodal natural killer T cell lymphoma (ENKTL) is a rare subtype of non-Hodgkin lymphoma with invariable infection of lymphoma cells with Epstein-Barr virus (EBV), and the presence of EBV-DNA in the blood is a well-known prognosticator. However, there is no consensus on which blood compartment is more optimal for predicting survival outcomes.

Methods

We analyzed 60 patients who were newly diagnosed with ENKTL from a prospectively collected database. EBV-DNA was measured in the whole-blood (WB) and plasma at the time of diagnosis and after treatment completion.

Results

EBV-DNA was detected in pre-treatment WB and plasma in 37 (61.7%) and 23 (38.3%) patients, respectively. The presence of pre-treatment plasma EBV-DNA was significantly associated with advanced stage while presence of WB EBV-DNA did not. Positivity of pre-treatment plasma-EBV, but not WB EBV-DNA, was independently associated with poor PFS (HR, 4.22;95% CI, 1.79–9.97; P=0.001) and OS (HR, 8.38; 95% CI, 3.03–23.19; P<0.001) in the multivariate analysis. After treatment completion, positivity of plasma-EBV was independently associated with poor PFS (HR, 9.41; 95% CI, 2.27–39.02; P=0.002) and OS (HR, 32.38; 95% CI, 3.25–322.56; P=0.003), whereas no significant association was observed between WB-EBV status and survival outcomes.

Conclusions

Our results suggest that EBV-DNA in the plasma has better prognostic values than WB in patients with ENKTL.

Analysis of latent T-cell epitopes in Epstein-Barr virus isolated from extranodal nasal-type natural killer/T-cell lymphoma in Taiwanese population

Extranodal nasal-type natural killer (NK)/T-cell lymphoma (NKTCL) is an aggressive lymphoma that is prevalent among East Asian and South American populations. Although Epstein-Barr virus (EBV) is commonly detected in NKTCL, there are limited studies that have analyzed the EBV genomic variations in NKTCL. In this study, 8 EBV latent genes were analyzed using targeted gene sequencing in 23 formalin-fixed paraffin-embedded tissues derived from 18 patients with NKTCL. Five cases with paired samples were comparatively analyzed. The consistency of EBV sequencing data between tissue samples was high (96.3%-98.7%), whereas that of variant calling among the tissue samples and plasma samples (74.3%-79.2%) was low. The highest densities of non-synonymous variants were detected in the EBNA3B gene. Among the 74 known T-cell epitopes, 363 non-synonymous variants were identified in 32 (43.2%) epitopes. Additionally, the AVFDRKSDAK (A1S/P and V2F/M/L) and YHLIVDTDSL (I4L and L10R/V/G/H) epitopes were associated with 5 patterns of amino acid changes in EBNA3B and EBNA-2, respectively. The frequency of variation in the human leukocyte antigen (HLA)-restricted epitopes with corresponding HLA types common among Taiwanese population was significantly low (P = 0.011), whereas that in anchor residues was significantly high (P = 0.012). In conclusion, this study demonstrated the genomic diversity of EBV in NKTCL and its correlation with the HLA-restricted epitope variations in Taiwanese population. The findings of this study provide useful insights for the development of novel therapeutic strategies for NKTCL.

[Clinical characteristics and prognostic analysis of advanced-stage extranodal NK/T cell lymphoma]

Objective: This study aimed to explore the clinical characteristics, survival rate, and prognostic factors of advanced-stage extranodal nasal type NK/T cell lymphoma (ENKTL) patients. Methods: The clinical data of 51 advanced-stage ENKTL patients in Peking Union Medical College Hospital from January 2012 to September 2019 were retrospectively analyzed. The clinical characteristics, treatment responses, survival rate, and prognostic factors were elucidated. The differences between nasal and non-nasal type and the significance of EBV-DNA in treatment response assessment and prognosis analysis were also evaluated. Results: The male-to-female ratio in the whole group was 2.9∶1 with a median age of 42 years old (range, 14-67 years) . The median follow-up time was 30 months (range, 1-78 months) . The one- and three-year progression-free survival (PFS) rates for the whole cohort were 34.1% and 24.6%, respectively, and the one- and three-year overall survival (OS) rates were 39.9% and 26.6%, respectively. The ratio of nasal to non-nasal type was 1.6∶1. The proportion of hemophagocytic lymphohistiocytosis (HLH) was significantly higher in non-nasal-type patients than nasal-type (P=0.039) , and the complete response (CR) rate of first-line chemotherapy is significantly lower in non-nasal type patients (P=0.008) . The median OS for nasal and non-nasal types were nine months and four months, respectively. The three-year PFS rates of nasal and non-nasal type patients were 36.0% and 10.0% (P=0.029) , respectively, and the three-year OS rates were 37.9% and 11.4% (P=0.050) , respectively. The correlation between the Epstein-Barr virus DNA (EBV-DNA) and treatment response were satisfactory. Survival curve between baseline EBV-DNA-negative and EBV-DNA-positive patients showed no significant difference. The three-year OS rates of EBV-DNA-negative and EBV-DNA-positive patients after one cycle of treatment were 77.9% and 8.1% (P=0.002) , respectively. In a multivariate analysis, EBV-DNA-positive following one cycle of treatment was an independent adverse prognostic factor for OS. Conclusions: The efficacy of pegaspargase-based chemotherapy and long-term survival of advanced-stage ENKTL patients were still poor. Clinical characteristics, treatment response, and long-term survival of non-nasal-type patients were worse than that of nasal-type patients. In a multivariate analysis, EBV-DNA-positive after one cycle of treatment was an independent adverse prognostic factor for OS. It can be used for early prediction of treatment response and prognosis.

Clinical characteristics and survival of extranodal natural killer/T-cell lymphoma: a single-center 12-year retrospective analysis

The characteristics and survival of 218 patients with extranodal natural killer/T-cell lymphoma (ENKTCL) were analyzed in this retrospective study. The median progression-free survival (PFS) and overall survival (OS) were 10.9 months and 50.5 months, respectively. Sequential chemoradiotherapy achieved a 74.5% overall response rate (ORR) and a 30.9% 5-year PFS rate in patients with localized stage. Asparaginase-containing protocols demonstrated superior prognosis in advanced cases, with a median FPS at 5.7 months, compared to 1.9 months without asparaginase. Initial treatment with P-GEMOX regimens showed superior ORR and PFS compared to the SMILE regimen, with lower toxicities. Hematopoietic stem cell transplantation (HSCT) improved the PFS and OS of refractory or relapsed (R/R) cases. PD-1/PD-L1 antibody could achieve a median PFS at 4.0 months and a median OS at 14.6 months in R/R patients for whom salvage therapies failed. High-risk PINK-E score was the only independent adverse prognostic factor for PFS and OS.

Management of NK/T-Cell Lymphoma, Nasal Type

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a rare peripheral T-cell lymphoma associated with Epstein-Barr virus. It most often presents as limited-stage disease in patients of East Asian descent with a palatal deformity caused by erosion of the tumor through the hard palate. Limited-stage disease is often curable with the use of l-asparaginase-based chemotherapy and high-dose radiation therapy. Obtaining an accurate diagnosis is essential, because treatment with standard lymphoma regimens and omission of radiation severely compromise the likelihood of long-term survival. Conversely, patients with advanced disease have a poor prognosis and are recommended for asparaginase-based chemotherapy followed by consolidation with autologous transplantation as a potentially curative approach. Progress often has been hampered by the rarity of this disease. However, discovery of common genetic alterations in pathways that promote growth and inhibit apoptosis, and actionable markers such as CD30 (among others), have begun to broaden the availability of novel drugs (eg, targeted therapies). There is also cautious optimism about immunotherapies, such as checkpoint blockade and novel cellular therapies that target Epstein-Barr virus. Advances in treatment and understanding of the genetic landscape of this disease offer hope for improved treatment outcomes.

Pegaspargase Combined with Concurrent Radiotherapy for Early-Stage Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type: A Two-Center Phase II Study

Background

Concurrent chemoradiotherapy (CCRT) is expected to improve local and systemic disease control and has been established as a standard therapy for several types of solid tumors. Considering the benefits of frontline radiation and pegaspargase in localized extranodal natural killer (NK)/T‐cell lymphoma, nasal type (ENKTL), we conducted a phase II study on pegaspargase‐based CCRT to explore an effective treatment.

Materials and Methods

In this study, 30 patients with newly diagnosed nasal ENKTL in stages IE to IIE received CCRT (radiation 50 Gy and two cycles of pegaspargase 2,500 unit/m² every 3 weeks). Four courses of pegaspargase were performed after CCRT.

Results

The patients completed CCRT and four cycles of pegaspargase. The complete remission (CR) rate was 90%, with a 95% confidential interval (CI) of 73.5%–97.9% after CCRT. The CR rate was 100% (95% CI, 88.4%–100%) at the end of the treatment. The 2‐year overall survival and progression‐free survival rates were 90.9% (95% CI, 78.4%–100%) and 92.8% (95% CI, 83.2%–100%), respectively. The major adverse events were in grades 1–2.

Conclusion

Preliminary data indicate that pegaspargase combined with concurrent radiotherapy for newly diagnosed patients with nasal ENKTL was efficacious and well tolerated. Registered atwww.chictr.org. Clinical Trial Registration Number. ChiCTR‐OIC‐15007662.

Implications for Practice

This clinical trial, evaluating the efficacy and toxicity of concurrent chemoradiotherapy by using single‐drug pegaspargase for patients with extranodal natural killer/T‐cell lymphoma, nasal type (ENKTL) in stage IE to IIE, showed pegaspargase combined with concurrent radiotherapy was efficacious and well tolerated. Pegaspargase has a long half‐life and is easy to administer via intramuscular injection. Consequently, pegaspargase combined with concurrent radiotherapy for patients with ENKTL can be completed in the outpatient clinic.

This phase II clinical study evaluated the efficacy and toxicity of concurrent chemoradiotherapy using single‐drug pegaspargase for patients with nasal‐type extranodal NK/T‐cell lymphoma.