WHO Classification of Malignant Lymphomas in Korea: Report of the Third Nationwide Study

Novel clinical risk stratification and treatment strategies in relapsed/refractory peripheral T-cell lymphoma

Peripheral T cell lymphoma (PTCL) represents a group of heterogeneous hematological malignancies, which are notoriously challenging to treat and outcomes are typically poor. Over the past two decades, clinical prognostic indices for patient risk stratification have evolved, while several targeted agents are now available to complement combination chemotherapy in the frontline setting or as a salvage strategy. With further understanding of the molecular pathobiology of PTCL, several innovative approaches incorporating immunomodulatory agents, epigenetic therapies, oncogenic kinase inhibitors and immunotherapeutics have come to the forefront. In this review, we provide a comprehensive overview of the progress in developing clinical prognostic indices for PTCL and describe the broad therapeutic landscape, emphasizing novel targetable pathways that have entered early phase clinical studies.

Primary extranodal lymphomas: Five-year experience from a tertiary care center of North India

BACKGROUND

Primary extranodal lymphomas (pENL) are lymphomas with minimal nodal involvement and dominant extranodal disease. We aimed to study the prevalence and clinicopathological characteristics of pENL presenting at our center over 5 years from January 2015 to January 2020.

METHODS

This is a cross-sectional study of pENL patients in which relevant clinical and laboratory data was collected including demography, site, stage, international prognostic index-revised, imaging findings, hematological, and biochemical parameters and comorbidities including underlying immunodeficiency. The paraffin blocks were subjected to routine hematoxylin and eosin stain and immunohistochemistry with standard lymphoma panel.

RESULTS

Of 341 lymphomas, 73 (21.4%) were pENL with commonest site being gastrointestinal tract (31.5%) followed by head and neck (23.2%) and soft tissues (9.6%). Diffuse large B-cell lymphoma (DLBCL) (39.7%) was the commonest histological type (germinal center type-48%, nongerminal center-52%) followed by marginal zone lymphomas (MZL) (23.3%) and primary CNS lymphoma (8.2%). Primary breast lymphoma, primary bone marrow lymphoma, and follicular lymphoma constituted 4.1, 5.4, and 4.1% of pENL, respectively. There was a case of high grade B cell lymphoma of ileum with features intermediate between DLBCL and Burkitt. Other unusual pENL were anaplastic DLBCL of tonsils, DLBCLs of bone marrow with M band, MZL of base of tongue, Richter's transformation of tonsillar small lymphocytic lymphoma, and follicular lymphoma presenting as pericardial mass. Of 12 cases of T-non-Hodgkin lymphoma, commonest were mycosis fungoides (4/12) followed by mediastinal T-lymphoblastic lymphoma (2/12) and peripheral T-cell lymphoma (2/12).

CONCLUSION

pENL has unique clinical presentation depending on the location with site-specific distribution of histological subtypes.

Identification and overcoming rituximab resistance in diffuse large B-cell lymphoma using next-generation sequencing

BACKGROUND/AIMS

Although rituximab, an antiCD20 monoclonal antibody, has dramatically improved the clinical outcomes of diffuse large B-cell lymphoma, rituximab resistance remains a challenge.

METHODS

We developed a rituximab-resistant cell line (RRCL) by sequential exposure to gradually increasing concentrations of rituximab in a rituximab-sensitive cell line (RSCL). When the same dose of rituximab was administered, RRCL showed a smaller decrease in cell viability and apoptosis than RSCL. To determine the differences in gene expression between RSCL and RRCL, we performed next-generation sequencing.

RESULTS

In total, 1,879 differentially expressed genes were identified, and in the over-representation analysis of Consensus-PathDB, mitogen-activated protein kinase (MAPK) signaling pathway showed statistical significance. MAPK13, which encodes the p38δ protein, was expressed more than four-fold in RRCL. Western blot analysis revealed that phosphop38 expression mainwas increased in RRCL, and when p38 inhibitor was administered, phosphop38 expression was significantly decreased. Therefore, we hypothesized that p38 MAPK activation was associated with rituximab resistance. Previous studies have suggested that p38 is associated with NF-κB activation. Deferasirox has been reported to inhibit NF-κB activity and suppress phosphorylation of the MAPK pathway. Furthermore, it also has cytotoxic effects on various cancers and synergistic effects in overcoming drug resistance. In this study, we confirmed that deferasirox induced dose-dependent cytotoxicity in both RSCL and RRCL, and the combination of deferasirox and rituximab showed a synergistic effect in RRCL at all combination concentrations.

CONCLUSION

We suggest that p38 MAPK, especially p38δ, activation is associated with rituximab resistance, and deferasirox may be a candidate to overcome rituximab resistance.

Epidemiological Characteristics of Peripheral T-Cell Lymphoma: A Population-Based Study

Objects

The aim of this study is to explore the epidemiological characteristics of peripheral T-cell lymphoma in Beijing.

Methods

 All data were extracted from the Beijing Cancer Registry database from January 1, 2007, to December 31, 2018. Segi’s World Standard Population was used to estimate the age-standardized rate (ASR). Changes in trends were examined using joinpoint regression analysis. The observed survival was estimated by the Kaplan–Meier method. Relative survival was calculated using Ederer II and standardized using the Brenner method and International Cancer Survival Standard (ICSS) group 1 age structure. Stratified by gender, area, and histological type, incidence, mortality, and age of onset trends were observed in Beijing.

Results

 In Beijing, there were 801 new cases and 463 deaths of T-cell lymphoma from 2007 to 2018. Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) was the most prevalent subtype (37.45%), followed by angioimmunoblastic T-cell lymphoma (AITL; 20.35%), NK/T-cell lymphoma (NK/TCL; 17.60%), and anaplastic large cell lymphoma (ALCL; 10.24%). The crude incidence and mortality rates were 0.52 and 0.30 per 100,000 person-years, respectively, whereas the age-standardized incidence and mortality rates (ASIR and ASMR) were 0.35 and 0.18 per 100,000 person-years, respectively. Both ASIR and ASMR were more prevalent in men (0.48 and 0.24 per 100,000) and urban area (0.38 and 0.19 per 100,000) than in women (0.22 and 0.11 per 100,000) and rural area (0.30 and 0.15 per 100,000). The average annual percentage change (AAPC) of ASIR and ASMR was 5.72% (95% confidence interval (CI): 1.79%–9.81%) and 4.35% (95% CI: −0.09%–8.99%), respectively. The age-specific incidence rate increased with age and peaked at the age groups of 10–14 and 80–84. The mean and median age of onset increased between 2007 and 2018. In addition, it decreased after the age of onset was age standardization (β = −0.41, P = 0.26). The 5-year age-standardized relative survival was 39.02% for all patients, 58.14% for NK/TCL, 57.60% for ALCL, 31.38% for AITL, and 29.18% for PTCL-NOS.

Conclusions

 T-cell lymphoma incidence was rising, but survival was dismal in Beijing, indicating the need for improved early diagnosis and standardized treatment.

Estimating the global burden of Epstein-Barr virus-related cancers

BACKGROUND

More than 90% of the adult population globally is chronically infected by the Epstein-Barr virus (EBV). It is well established that EBV is associated with a number of malignancies, and advances in knowledge of EBV-related malignancies are being made every year. Several studies have analysed the global epidemiology and geographic distribution of EBV-related cancers. However, most have only described a single cancer type or subtype in isolation or limited their study to the three or four most common EBV-related cancers. This review will present an overview on the spectrum of cancers linked to EBV based on observations of associations and proportions in the published literature while also using these observations to estimate the incidence and mortality burden of some of these cancers.

METHOD

We have reviewed the literature on defining features, distribution and outcomes across six cancers with a relatively large EBV-related case burden: Nasopharyngeal carcinoma (NPC), Gastric carcinoma (GC), Hodgkin lymphoma (HL), Burkitt lymphoma (BL), Diffuse large B-cell lymphoma (DLBCL) and Extranodal NK/T-cell lymphoma, Nasal type (ENKTL-NT). We retrieved published region-specific EBV-related case proportions for NPC, GC, HL and BL and performed meta-analyses on pooled region-specific studies of EBV-related case proportions for DLBCL and ENKTL-NT. We match these pooled proportions with their respective regional incidence and mortality numbers retrieved from a publicly available cancer database. Additionally, we also reviewed the literature on several other less common EBV-related cancers to summarize their key characteristics herein.

CONCLUSION

We estimated that EBV-related cases from these six cancers accounted for 239,700-357,900 new cases and 137,900-208,700 deaths in 2020. This review highlights the significant global impact of EBV-related cancers and extends the spectrum of disease that could benefit from an EBV-specific therapeutic.

Primary Gastrointestinal T/NK Cell Lymphoma

Primary gastrointestinal T/NK cell lymphoma (GI-TNKL) is an uncommon and heterogeneous group of lymphoid malignancies. We aimed to investigate their subtype distribution, clinicopathologic characteristics, and clinical outcomes. A total of 38 GI-TNKL cases and their clinical and pathological characteristics were analyzed. GI-TNKL occurred in adults with a median patient age in the sixth decade of life and showed a slight male predominance. The most common histologic type was extranodal NK/T-cell lymphoma, nasal type (ENKTL; 34.2%), followed by monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL; 31.6%), intestinal T-cell lymphoma, NOS (ITCL, NOS, 18.4%), anaplastic large cell lymphoma, ALK-negative (ALCL, ALK-; 13.2%). The small intestine was the primary affected region. More than 90% of patients complained of various GI symptoms and cases with advanced Lugano stage, high IPI score, or bowel perforation that required emergent operation were not uncommon. GI-TNKL also showed aggressive behavior with short progression-free survival and overall survival. This thorough clinical and pathological descriptive analysis will be helpful for accurate understanding, diagnosis, and treatment.

Real-world data on the survival outcome of patients with newly diagnosed Waldenström macroglobulinemia

BACKGROUND/AIMS

Waldenström macroglobulinemia (WM) is a rare lymphoproliferative disorder that usually follows an indolent clinical course. However, some patients show an aggressive clinical course leading to death. We explored the risk factors predicting poor prognosis in WM patients.

METHODS

We retrospectively analyzed 47 patients diagnosed with WM between 2000 and 2018 to explore risk factors predicting poor prognosis using various clinical and laboratory parameters and risk models including the International Prognostic Staging System for WM (IPSS-WM).

RESULTS

Over a median follow-up duration of 80.4 months, 29 patients died. The main causes of death were disease progression, organ failure related to amyloidosis, and infection. The median overall survival (OS) was 55.1 months, and 14 patients, including three with amyloidosis, died within 2 years. Serum β2-microglobulin level higher than 4 mg/dL was significantly associated with poor OS. Accordingly, the IPSS-WM showed a significant association with poor prognosis compared with other risk models, and the low-risk group had better OS than intermediate- and high-risk groups. In the retrospective analysis using the results of targeted sequencing in two cases representing good and bad prognosis, different patterns of mutation profiles were observed, including mutations of MYD88, TP53, ARID1A, and JAK2 in a refractory case.

CONCLUSION

Serum β2-microglobulin could be a single biomarker strongly predictive of poor survival of WM patients, and the low-risk group of the IPSS-WM risk model including serum β2-microglobulin has better prognostic value than other risk models. Mutation analysis also might provide additional information to predict high-risk patients.

Clinical course of duodenal mucosa-associated lymphoid tissue lymphoma: Comparison with gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND AND AIM

There are few cases of duodenal mucosa-associated lymphoid tissue (MALT) lymphoma reported in the literature, and little is known about the clinical course of this disease. Here, we aimed to characterize the clinical features of duodenal MALT lymphoma by comparison with gastric MALT lymphoma.

METHODS

Thirteen patients diagnosed with duodenal MALT lymphoma at Asan Medical Center from March 1997 to February 2017 were included in this retrospective study, along with patients with gastric MALT lymphoma, matched by age and sex at a 1:10 ratio.

RESULTS

Median age of patients with duodenal MALT lymphoma was 49 (range 20-72) years, and 53.8% (7/13) were male. Comparison of patient characteristics indicated that Helicobacter pylori infection (46.2% vs 90.8%, P < 0.001) and lymph node metastasis (23.1% vs 5.4%, P = 0.049) rates differed between patients with duodenal and gastric MALT lymphoma. Overall complete remission (61.5% vs 86.2%, P = 0.021) and complete remission after initial H. pylori eradication therapy (50% vs 87.7%, P = 0.037) were significantly lower in patients with duodenal than gastric MALT lymphoma. Complications including bleeding, stricture, and transformation to high-grade lymphoma occurred in a total of seven patients (4.9%), with a higher incidence in patients with duodenal than gastric MALT lymphoma (38.5% vs 1.5%, P < 0.001).

CONCLUSIONS

Duodenal MALT lymphoma is very rare, and treatment outcomes appear to be inferior to those of gastric MALT lymphoma.

Cost-utility analysis of pralatrexate for relapsed or refractory peripheral T-cell lymphoma based on a case-matched historical control study along with single arm clinical trial

BACKGROUND

Patients with relapsed or refractory peripheral T-cell lymphoma (R/R PTCL) treated with pralatrexate have previously shown superior overall survival (OS) compared to those who underwent conventional chemotherapy (CC, 15.4 vs. 4.07 months). We conducted an economic evaluation of pralatrexate from a societal perspective in Korea based on data from the PROPEL phase II study.

METHODS

Using a Markov model with a weekly cycle, we simulated the experience of patients with R/R PTCL receiving pralatrexate or CC for 15 years. The model consists of five health states; initial treatment, treatment pause, subsequent treatment, stem cell transplantation (SCT) success, and death. Comparative effectiveness was based on PROPEL phase II single-arm study and its matched historical control analysis. Costs included drug, drug administration, monitoring, adverse event management, and SCT costs.

RESULTS

The incremental cost-effectiveness ratio of the base case was $39,153 per quality-adjusted life-year (QALY) gained. The results of one-way sensitivity analysis ranged from $33,949 to $51,846 per QALY gained, which remained within an implicit willingness-to-pay (WTP) threshold of anticancer drugs in Korea.

CONCLUSIONS

Pralatrexate is a cost-effective intervention with improved OS and incremental costs within the WTP limit. Pralatrexate could function as a new therapeutic option for patients suffering from life-threatening R/R PTCL.

Discovery of Novel Recurrent Mutations and Clinically Meaningful Subgroups in Nodal Marginal Zone Lymphoma

Nodal marginal zone lymphoma (NMZL) is a rare B-cell neoplasm, the genetic and transcriptomic landscape of which are unclear. Using high-throughput sequencing for whole-exome and transcriptome, we investigated the genetic characteristics of NMZL in a discovery cohort (n = 8) and validated their features in an extended cohort (n = 30). Novel mutations in NFKBIE and ITPR2 were found in 7.9% (3/38) and 13.9% (5/36), respectively, suggesting roles for the NF-κB pathway and B-cell-receptor-mediated calcium signaling pathway in the pathogenesis of NMZL. RNA-seq showed that NMZLs were characterized by an aberrant marginal zone differentiation, associated with an altered IRF4-NOTCH2 axis and the enrichment of various oncogenic pathways. Based on gene expression profile, two subgroups were identified. Compared with subgroup 1, subgroup 2 showed the following: the significant enrichment of cell cycle-associated and MYC-signaling pathways, a more diverse repertoire of upstream regulators, and higher Ki-67 proliferation indices. We designated two subgroups according to Ki-67 labeling, and subgroup 2 was significantly associated with a shorter progression-free survival (p = 0.014), a greater proportion of large cells (p = 0.009), and higher MYC expression (p = 0.026). We suggest that NMZL has unique features and, in this study, we provide information as to the heterogeneity of this enigmatic entity.

Treatment of mantle cell lymphoma in Asia: a consensus paper from the Asian Lymphoma Study Group

BACKGROUND

Mantle cell lymphoma (MCL) is a B cell malignancy that can be aggressive and with a poor prognosis; the clinical course is heterogeneous. The epidemiology of MCL in Asia is not well documented but appears to comprise 2-6% of all lymphoma cases based on available data, with variation observed between countries. Although international guidelines are available for the treatment of MCL, there is a lack of published data or guidance on the clinical characteristics and management of MCL in patient populations from Asia. This paper aims to review the available treatment and, where clinical gaps exist, provide expert consensus from the Asian Lymphoma Study Group (ALSG) on appropriate MCL management in Asia. BODY: Management strategies for MCL are patient- and disease stage-specific and aim to achieve balance between efficacy outcomes and toxicity. For asymptomatic patients with clearly indolent disease, observation may be an appropriate strategy. For stage I/II disease, following international guidelines is appropriate, which include either a short course of conventional chemotherapy followed by consolidated radiotherapy, less aggressive chemotherapy regimens, or a combination of these approaches. For advanced disease, the approach is based on the age and fitness of the patient. For young, fit patients, the current practice for induction therapy differs across Asia, with cytarabine having an important role in this setting. Hematopoietic stem cell transplantation (HSCT) may be justified in selected patients because of the high relapse risk. In elderly patients, specific chemoimmunotherapy regimens available in each country/region are a treatment option. For maintenance therapy after first-line treatment, the choice of approach should be individualized, with cost being an important consideration within Asia. For relapsed/refractory disease, ibrutinib should be considered as well as other follow-on compounds, if available.

CONCLUSION

Asian patient-specific data for the treatment of MCL are lacking, and the availability of treatment options differs between country/region within Asia. Therefore, there is no clear one-size-fits-all approach and further investigation on the most appropriate sequence of treatment that should be considered for this heterogeneous disease.

Practical Approach to the Histologic Diagnosis of Gastrointestinal Lymphomas Through the First-line Marker Battery of CD20, CD3, CD30, and Epstein-Barr Virus-encoded RNAs

The gastrointestinal (GI) tract is a prevalent site for extranodal lymphomas. Some subtypes of GI tract lymphomas are aggressive and have dismal clinical outcomes. Therefore, prompt histopathologic detection of such types can be very important. We thus introduce a practical approach in the histopathologic diagnosis of GI lymphomas according to the revised World Health Organization (WHO) classification. When lymphocyte proliferation is found in the GI tract, a stepwise approach can help narrow down the differential diagnoses. When considering subtype incidence, macroscopic findings, and microscopic patterns, applying a first-line marker battery of CD20, CD3, CD30, and Epstein-Barr virus-encoded RNAs can effectively narrow down the top differential diagnoses at the initial step. Generally, the most common subtype among GI tract lymphomas is B-cell non-Hodgkin lymphoma identified by CD20 expression, followed by T-cell and NK-cell non-Hodgkin lymphomas identified by the CD3 expression, and some subtypes are defined by Epstein-Barr virus infection or CD30 expression. Macroscopically, lymphomas present as various gross types, such as large masses, small lesions, superficial and shallow lesions, polyp-like or polyposis-like features, or ulcer/necrosis/perforation. Microscopically, large pleomorphic cells or small to medium-sized tumor cells grow with various architectures and tumor microenvironments. Incorporation of macroscopic and microscopic features and the stepwise immunophenotyping may be a practical approach to the differential diagnosis of aggressive lymphoma, indolent/low-grade lymphoma, or benign to indolent lymphoproliferative disease. Exceptions always exist; this approach focuses on the relatively prevalent circumstances of lymphomatous lesions initially encountered in the GI tract.

Morphologic variant of follicular lymphoma reminiscent of hyaline-vascular Castleman disease

Follicular lymphoma (FL) with hyaline-vascular Castleman disease (FL-HVCD)-like features is a rare morphologic variant, with fewer than 20 cases in the literature. Herein, we report a case of FL-HVCD in a 37-year-old female who presented with isolated neck lymph node enlargement. The excised lymph node showed features reminiscent of HVCD, including regressed germinal centers (GCs) surrounded by onion skin-like mantle zones, lollipop lesions composed of hyalinized blood vessels penetrating into regressed GCs, and hyalinized interfollicular stroma. In addition, focal areas of abnormally conglomerated GCs composed of homogeneous, small centrocytes with strong BCL2, CD10, and BCL6 expression were observed, indicating partial involvement of the FL. Several other lymphoid follicles showed features of in situ follicular neoplasia. Based on the observations, a diagnosis of FL-HVCD was made. Although FLHVCD is very rare, the possibility of this variant should be considered in cases resembling CD. Identification of abnormal, neoplastic follicles and ancillary immunostaining are helpful for proper diagnosis.

Cutaneous lymphoma in Japan, 2012-2017: A nationwide study

BACKGROUND

The types of cutaneous lymphoma (CL) and their incidences can vary among geographic areas or ethnic groups.

OBJECTIVE

This study aimed to investigate the incidence of various CL types in Japan using epidemiological data from a nationwide registration system for CL.

METHODS

A questionnaire was sent to participating hospitals, all of which had been approved to conduct residency programs for board-certified dermatologists by the Japanese Dermatological Association. Data from patients newly diagnosed with CL were collected electronically.

RESULTS

Between 2012 and 2017, 2547 new patients with CL from the dermatological institutes were registered. In total, 2090 patients had primary CL and 453 had secondary CL. Those with primary CL included 1609 (77.0 %) patients with mature T- and natural killer (NK)-cell neoplasms, 442 (21.1 %) with B-cell neoplasms, and 39 (1.9 %) with blastic plasmacytoid dendritic cell neoplasms. Mycosis fungoides (MF) was the most common CL subtype in the present study (1003 patients, 48.0 %), and 72.4 % of MF patients had early-stage disease, similar to observations in previous studies on other cohorts. Primary cutaneous CD30+ T-cell lymphoproliferative disorders and adult T-cell leukemia/lymphoma were the second and third most common subtypes, respectively.

CONCLUSION

Compared to that in our previous cohort (2007-2011), the number of registered T- and NK-cell CL cases decreased, whereas that of B-cell CL cases increased from 44.8-73.7 patients/year. These results provide insight into CL trends within the Japanese population, which might contribute to a better understanding of the disease.

Epstein-Barr virus NK and T cell lymphoproliferative disease: report of a 2018 international meeting

Epstein-Barr virus (EBV) normally infects B cells, but in some persons the virus infects T or NK cells. Infection of B cells can result in infectious mononucleosis, and the virus is associated with several B cell malignancies including Hodgkin lymphoma, Burkitt lymphoma, and diffuse large B cell lymphoma. Infection of T or NK cells with EBV is associated with extranodal NK/T cell lymphoma, aggressive NK-cell leukemia, systemic EBV-associated T-cell lymphoma, and chronic active EBV disease, which in some cases can include hydroa vacciniforme-like lymphoproliferative disease and severe mosquito bite allergy. While NK and T cell lymphoproliferative disease is more common in Asia and Latin America, increasing numbers of cases are being reported from the United States and Europe. This review focuses on classification, clinical findings, pathogenesis, and recent genetic advances in NK and T cell lymphoproliferative diseases associated with EBV.

Changing trends in lymphoid neoplasm distribution in South Korea: analysis of 8615 cases from a single institute, 1997-2016: An observational study

The purpose of this study was to evaluate changes in the proportion of lymphoid neoplasm subtypes in South Korea. A total of 8615 cases of lymphoid neoplasms diagnosed in 1997-2016 at Samsung Medical Center in South Korea were classified according to the 2008 World Health Organization system. The total number and proportion of lymphoid neoplasms were compared between these two decades, with data from nationwide studies, and with other countries. To evaluate changes in the proportion of subtypes, crude rate of each subtype per 100 lymphoma patients during each decade and age adjusted rate were calculated. There were 3024 patients with lymphoid neoplasm in 1997-2006, and 5591 in 2007-2016, which represents an average increase of 1.85 times over the 20-year study period. Crude rate and age adjusted rate were increased in Hodgkin's lymphoma and mature B cell lymphoma while precursor lymphoid neoplasms and mature T cell lymphoma were decreased. Among B cell neoplasms, age adjusted rate of plasma cell neoplasm, follicular lymphoma, mantle cell lymphoma increased while there was no significant change in extranodal marginal zone lymphoma and Burkitt lymphoma. The increase in follicular lymphoma was due to the increases in nodal follicular lymphoma of low grade and duodenal-type follicular lymphoma. These results are consistent with the dynamics of causative factors, including socioeconomic factors, in Korea.

Phase II study of R-CVP followed by rituximab maintenance therapy for patients with advanced marginal zone lymphoma: consortium for improving survival of lymphoma (CISL) study

Background

The response rate and survival improvement for rituximab, a CD20-targeting monoclonal antibody, have been demonstrated in marginal zone lymphoma (MZL) as monotherapy and in combination with chemotherapeutic regimens, yet relapses still occur despite treatment completion. Thus, extending the period of remission in MZL patients remains an essential goal. This multicenter, single-arm, open-label phase II study evaluated the survival efficacy of 2 years of rituximab-maintenance therapy in patients with stage III–IV CD20-positive MZL who had responded to first-line R–CVP (rituximab, cyclophosphamide, vincristine, and prednisolone). The objective of this study was to determine whether rituximab maintenance following R–CVP warrants further investigation.

Methods

Prior to rituximab-maintenance therapy, patients received 6–8 cycles of first-line R–CVP therapy for stage III–IV MZL. Rituximab (375 mg/m²), cyclophosphamide (750 mg/m²), and vincristine (1.4 mg/m²; maximum 2 mg) were administered via an intravenous infusion on day 1 of each 3-week cycle, while oral prednisolone (100 mg) was given on days 1–5 of each 3-week cycle. The patients who achieved complete response (CR), partial response (PR), or stable disease (SD) to R–CVP treatment, were prescribed rituximab-maintenance therapy which was administered intravenously at a dose of 375 mg/m² every 8 weeks for up to 12 cycles. The primary endpoint was progression-free survival (PFS). Secondary endpoints were overall survival (OS) and treatment safety.

Results

47 patients were enrolled, of whom, 45 (96%) received rituximab-maintenance treatment. Fifteen (33%) patients had nodal MZL. Following R–CVP first-line therapy, 20 (44%), 22 (49%), and 3 (7%) patients achieved CR, PR, and SD, respectively. After a median follow-up of 38.2 months, their observed 3-year PFS rate was 81%. During the rituximab-maintenance, 6 PR and 1 SD patients achieved CR following the administration of R–CVP. Elevated LDH and the presence of B symptoms were found to be significant prognostic factors for PFS (P = 0.003) and demonstrated a 3-year OS rate of 90%. Rituximab-maintenance therapy was well tolerated, and the common treatment-emergent adverse events were sensory neuropathy (18%), myalgia (13%), fatigue (9%), and neutropenia (9%).

Conclusion

Rituximab-maintenance therapy following first-line R–CVP demonstrated good PFS in patients with stage III–IV MZL, in addition to a favorable toxicity profile.

Trial registration clinicaltrials.gov: NCT01213095

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

Pediatric non-Hodgkin lymphoma: Characteristics, stratification, and treatment at a single institute in Thailand

BACKGROUND

In the modern era of chemotherapy, the outcome of pediatric non-Hodgkin lymphoma (NHL) continues to improve internationally. Limited data such as information on epidemiology and survival, however, are available in Asian countries.

METHODS

Children (≤15 years old) diagnosed with histologically proven NHL from 1998 to 2014 were retrospectively analyzed.

RESULTS

In total, 114 patients were enrolled; they were predominantly male (65.8%) and had advanced disease (stage III, IV; 71.9%). Of these, 22.8% had Burkitt lymphoma, 20.2% had diffuse large B-cell lymphoma, 21.1% had lymphoblastic lymphoma, 20.2% had large cell lymphoma, and 15.8% had peripheral T-cell lymphoma. Twenty-nine patients died, especially of uncontrolled disease (62.1%) and infection (20.7%). During a median follow up of 78.4 months, Kaplan-Meier 5 year event-free and overall survival rates were 71.5% ± 4.3% and 74.8% ± 4.1%, respectively, regardless of subtype. B symptoms (i.e. systemic symptoms of fever, night sweats, and weight loss that can be associated with both Hodgkin's lymphoma and non-Hodgkin's lymphoma) and advanced disease had a significant negative impact on 5 year survival. No other prognostic factor was found, but survival tended to have a negative correlation with age.

CONCLUSIONS

Pediatric NHL is aggressive, with a high prevalence of peripheral T-cell lymphoma. The present treatment stratification seems to be effective compared with that used in developed countries.

Prevalence and Implications of Bone Marrow Involvement in Patients with Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Background/Aims

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach is an uncommon disease. Bone marrow involvement is reported even in patients with only a mucosal lesion. We evaluated the prevalence and risk factors of marrow involvement and its implications for diagnosis and treatment.

Methods

In total, 132 patients who were diagnosed with gastric MALT lymphoma at the National Cancer Center in Korea between January 2001 and December 2016 were enrolled in the study. The patient data were collected and analyzed retrospectively.

Results

Of the 132 patients, 47 (35.6%) were male, with a median age of 52 years (range, 17 to 81 years). The median follow-up duration was 48.8 months (range, 0.5 to 169.9 months). Helicobacter pylori infection was detected in 82 patients (62.1%). Most patients (80.3%) had stage IE1 according to the modified Ann Arbor staging system. Ninety-two patients underwent bone marrow evaluation, and four patients (4.3%) had marrow involvement. Of these patients, one presented with abdominal lymph node involvement, while the other three had stage IE1 disease if marrow involvement was disregarded. All three patients had no significant symptoms and were monitored after local treatment without evidence of disease aggravation.

Conclusions

Bone marrow involvement was found in 4.3% of the patients with gastric MALT lymphoma. Bone marrow examination may be deferred because marrow involvement does not change the treatment options or outcome in gastric MALT lymphoma confined to the stomach wall.

A risk stratification model for nodal peripheral T-cell lymphomas based on the NCCN-IPI and posttreatment Deauville score

PURPOSE

The aim of this study was to establish a risk-stratification model integrating posttreatment metabolic response using the Deauville score and the pretreatment National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) in nodal PTCLs.

METHODS

We retrospectively analysed 326 patients with newly diagnosed nodal PTCLs between January 2005 and June 2016 and both baseline and posttreatment PET/CT data. The final model was validated using an independent prospective cohort of 79 patients.

RESULTS

Posttreatment Deauville score (1/2, 3, and 4/5) and the NCCN-IPI (low, low-intermediate, high-intermediate, and high) were independently associated with progression-free survival: for the Deauville score, the hazard ratios (HRs) were 1.00 vs. 2.16 (95% CI 1.47-3.18) vs. 7.86 (5.66-10.92), P < 0.001; and for the NCCN-IPI, the HRs were 1.00 vs. 2.31 (95% CI 1.20-4.41) vs. 4.42 (2.36-8.26) vs. 7.09 (3.57-14.06), P < 0.001. Based on these results, we developed a simplified three-group risk model comprising a low-risk group (low or low-intermediate NCCN-IPI with a posttreatment Deauville score of 1 or 2, or low NCCN-IPI with a Deauville score of 3), a high-risk group (high or high-intermediate NCCN-IPI with a Deauville score of 1/2 or 3, or low-intermediate NCCN-IPI with a Deauville score of 3), and a treatment failure group (Deauville score 4 or 5). This model was significantly associated with progression-free survival (5-year, 70.3%, 31.4%, and 4.7%; P < 0.001) and overall survival (5-year, 82.1%, 45.5%, and 14.7%; P < 0.001). Similar associations were also observed in the independent validation cohort.

CONCLUSION

The risk-stratification model integrating posttreatment Deauville score and pretreatment NCCN-IPI is a powerful tool for predicting treatment failure in patients with nodal PTCLs.

The prognostic significance of CD11b+CX3CR1+ monocytes in patients with newly diagnosed diffuse large B-cell lymphoma

Despite their critical roles in angiogenesis and host immunosuppression within the tumor microenvironment, the prognostic significance of myeloid-lineage cells expressing CD11b and CX3CR1 in diffuse large B-cell lymphoma (DLBCL) has not been well studied. We prospectively enrolled newly-diagnosed DLBCL patients at two Korean institutions between May 2011 and Aug 2015. CD11b⁺CX3CR1⁺ cells were analyzed by flow cytometry using peripheral blood (PB) and bone marrow (BM) aspirate samples before treatments. Eighty-nine patients (52 males) were enrolled. The median age was 65 years (range, 19–88 years). Thirty-seven patients (42%) were classified as high-intermediate or high risk according to the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI). Patients were categorized into either high or low PB-/BM-CD11b⁺CX3CR1⁺ monocyte group according to the cutoffs identified by the receiver-operating-characteristics analysis (PB, 3.68%; BM, 3.45%). The high PB-CD11b⁺CX3CR1⁺ monocyte group was significantly associated with high-intermediate and high risk NCCN-IPI group (P = 0.004). With a median follow-up of 27.7 months (range, 1.7-60.4 months), the low PB-CD11b⁺CX3CR1⁺ monocyte group showed significantly better overall survival (OS) than the high PB-CD11b⁺CX3CR1⁺ monocyte group (3-year, 92.3% vs. 51.2%, respectively; P < 0.001). In contrast, no significant difference was observed between the high and low BM-CD11b⁺CX3CR1⁺ monocyte groups. Among patients with high-intermediate to high risk NCCN-IPI, the high PB-CD11b⁺CX3CR1⁺ monocyte group showed significantly worse OS than the low PB-CD11b⁺CX3CR1⁺ monocyte group (3-year, 29.3% vs. 80.2%, respectively; P = 0.008). Taken together, PB-CD11b⁺CX3CR1⁺ monocyte percentage correlates with the NCCN-IPI risk stratification, which enables identification of subgroups with extremely poor clinical outcomes.

Platelet to lymphocyte ratio (PLR) retains independent prognostic significance in advanced stage marginal zone lymphoma patients treated with rituximab, cyclophosphamide, vincristine, and prednisone combination chemotherapy (R-CVP): Consortium for Improving Survival of Lymphoma trial

Background

Rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP) is one of the effective chemotherapeutic regimens for patients with advanced stage marginal zone lymphoma (MZL). However, prognostic factors that affect the outcome of treatment for MZL are not well understood.

Methods

Between August 2006 and June 2013, patients with newly diagnosed stage III and IV MZL treated with R-CVP as a first-line therapy from 15 institutions were retrospectively analyzed. Patients' clinical and laboratory data at diagnosis were collected by review of medical records.

Results

A total of 80 patients were analyzed. Bone marrow involvement was observed in 30% cases. Twelve patients (15%) had nodal MZL, and 41.3% patients exhibited multiple mucosa-associated lymphoma tissue sites. Overall response rate was 91.3%, including 73.8% achieving complete response. Advanced MZL patients treated with R-CVP showed a 3-year progression-free survival (PFS) rate of 69.6%. Prognostic markers significantly affecting PFS in univariate analysis were platelet to lymphocyte ratio (PLR, <95 vs. ≥95, P=0.014), serum albumin (≤3.9 vs. >3.9 g/dL, P=0.008), and the International Prognostic Index (IPI) score (1 vs. 2–4, P=0.032). In multivariate analysis, only PLR (<95 vs. ≥95, HR 0.367, 95% CI, 0.139–0.971, P=0.043) was an independent risk factor for PFS.

Conclusion

PLR ≥95 at diagnosis is an independent prognostic marker for PFS in advanced stage MZL patients treated with R-CVP. This marker may aid clinicians in predicting the response to R-CVP chemotherapy in stage III and IV MZL patients.

Treatment outcome and risk analysis for cataract after radiotherapy of localized ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma

PURPOSE

We retrospectively reviewed the results of radiotherapy for localized ocular adnexal MALT lymphoma (OAML) to investigate the risk factors of cataract.

METHODS

Sixty-seven patients with stage IE OAML treated with radiotherapy at Seoul St. Mary's Hospital from 2001 to 2016 were included. Median treatment dose was 30 Gy. Lens protection was done in 52 (76%) patients. Radiation therapy (RT) extent was as follows: superficial (82.1%), tumor mass (4.5%), and entire orbital socket (13.4%). The risk factors for symptomatic cataract were analyzed using the Cox proportional hazard model.

RESULTS

Median follow-up time was 50.9 months (range, 1.9 to 149.4 months). All patients were alive at the time of analysis. There were 7 recurrences and there was no local recurrence. Median time to recurrence was 40.4 months. There were 14 cases of symptomatic cataract. Dose >30 Gy had hazard ratio of 3.47 for cataract (p = 0.026). Omitting lens protection showed hazard ratio of 4.10 (p = 0.008).

CONCLUSIONS

RT achieves excellent local control of ocular MALT lymphoma. Consideration of RT-related factors such as lens protection and radiation dose at the stage of RT planning may reduce the risk of RT-induced cataract after radiotherapy.

Geographical Correlations between Indoor Radon Concentration and Risks of Lung Cancer, Non-Hodgkin's Lymphoma, and Leukemia during 1999-2008 in Korea

Indoor radon is the second most important risk factor for lung cancer and may also be a risk factor for hematopoietic cancers, particularly in children and adolescents. The present study measured indoor radon concentration nationwide at 5553 points during 1989–2009 and spatially interpolated using lognormal kriging. The incidences of lung cancer, non-Hodgkin’s lymphoma (NHL), and leukemia, stratified by sex and five-year age groups in each of the 234 administrative regions in the country during 1999–2008, were obtained from the National Cancer Registry and used to calculate the standardized incidence ratios. After considering regional deprivation index values and smoking rates by sex in each region as confounding variables, the cancer risks were estimated based on Bayesian hierarchical modeling. We found that a 10 Bq/m³ increase in indoor radon concentration was associated with a 1% increase in the incidence of lung cancer in male and a 7% increase in NHL in female children and adolescents in Korea aged less than 20 years. Leukemia was not associated with indoor radon concentration. The increase in NHL risk among young women requires confirmation in future studies, and the radon control program should consider children and adolescents.

Serious fungal infections in Korea

Information on the incidence and prevalence of fungal infections is of critical value in public health policy. However, nationwide epidemiological data on fungal infections are scarce, due to a lack of surveillance and funding. The objective of this study was to estimate the disease burden of fungal infections in the Republic of Korea. An actuarial approach using a deterministic model was used for the estimation. Data on the number of populations at risk and the frequencies of fungal infections in those populations were obtained from national statistics reports and epidemiology papers. Approximately 1 million people were estimated to be affected by fungal infections every year. The burdens of candidemia (4.12 per 100,000), cryptococcal meningitis (0.09 per 100,000), and Pneumocystis pneumonia (0.51 per 100,000) in South Korea were estimated to be comparable to those in other countries. The prevalence of chronic pulmonary aspergillosis (22.4 per 100,000) was markedly high, probably due to the high burden of tuberculosis in Korea. The low burdens of allergic bronchopulmonary aspergillosis (56.9 per 100,000) and severe asthma with fungal sensitization (75.1 per 100,000) warrant further study. Oral candidiasis (539 per 100,000) was estimated to affect a much larger population than noted in previous studies. Our work provides valuable insight on the epidemiology of fungal infections; however, additional studies are needed.

Treatment outcomes of IMEP as a front-line chemotherapy for patients with peripheral T-cell lymphomas

Background

This study aimed to assess the treatment outcomes of ifosphamide, mesna, etoposide, and prednisolone (IMEP) combination regimen as a front-line chemotherapy in patients with peripheral T-cell lymphomas (PTCLs).

Methods

Clinical data of 38 newly diagnosed PTCLs patients who underwent IMEP at Busan Paik Hospital from January 2002 to December 2013 were retrospectively analyzed.

Results

The overall response rate was 68.5%, with 21 (55.3%) complete response/complete response unconfirmed and 6 (15.8%) partial response (PR). The median follow-up duration was 25.5 months (range, 0.2-87.3). The median overall survival was not reached and 2-year survival rate was 67%. The median progression free survival was 23 months. The most frequently reported adverse effects higher than grade 3 were hematologic toxicities including neutropenia (68.4%), thrombocytopenia (42.1%). There was no treatment-related mortality.

Conclusion

IMEP regimen is effective and safe as a front-line chemotherapy in patients with PTCLs.

The Roles of Radiotherapy and Chemotherapy in the Era of Multimodal Treatment for Early-Stage Nasal-Type Extranodal Natural Killer/T-Cell Lymphoma

PURPOSE

To evaluate radiotherapy (RT) and chemotherapy (CT) treatments of early-stage extranodal natural killer/T-cell lymphoma (ENKTL).

MATERIALS AND METHODS

Fifty-five patients with stage I or II ENKTL [n=39 (71%) and 16 (29%) patients, respectively] who were treated with RT between 1999 and 2013 were analyzed retrospectively. The median age was 54 years (range, 24-81). Patients were grouped by treatment modality as RT alone [n=19 (35%)], upfront CT plus RT [CT+RT, n=16 (29%)], and concurrent chemoradiotherapy [CCRT, n=20 (36%)]. The median RT dose was 48 Gy. Patient characteristics between each treatment group were well balanced. Patterns of failure and survival were analyzed.

RESULTS

The overall response rate after RT was 94.6%. Ten patients experienced distant failure, and seven experienced local failure comprising five in-field and two out-field failures. The local and distant failure rates in the RT-alone group were the same (16%). In the CT+RT group, the most common failure sites were local (19%). In the CCRT group, the most common failures were distant (25%). At a median follow-up of 56 months (range, 1-178 months), the 5-year overall survival (OS) and progression-free survival rates were 66% and 54%, respectively. The 5-year OS rate for the RT-alone and CT+RT groups were 76% and 69%, respectively, and the 2-year OS rate for the CCRT group was 62% (p=0.388).

CONCLUSION

In the era of multimodal treatment for ENKTL, RT alone using advanced techniques should be considered for local disease control, whereas maintenance CT regimens should be considered for distant disease control.

Immune reconstitution inflammatory syndrome versus non-immune reconstitution inflammatory syndrome lymphoma in HIV patients on antiretroviral therapy

Little is known about differences between immune reconstitution inflammatory syndrome (IRIS) and non-IRIS lymphoma in HIV patients on antiretroviral therapy (ART). The aim of this study was to describe the characteristics of IRIS and non-IRIS lymphoma in Korean HIV-positive patients on ART compared with lymphoma in those off ART. Of 1490 patients, 41 (3%) had lymphoma. Of these, 27 cases (66%) were classified as lymphoma off ART, eight as IRIS lymphoma, and six as non-IRIS lymphoma on ART. Hodgkin lymphoma was significantly more common among patients with non-IRIS lymphoma on ART than among those with lymphoma off ART (P = 0.005), whereas there was no Hodgkin lymphoma among IRIS lymphoma. Stage IV lymphoma was significantly rarer in non-IRIS lymphoma on ART than in lymphoma off ART (P = 0.007). Non-IRIS lymphoma on ART tends to have a better survival rate than lymphoma off ART (Kaplan-Meier survival analysis, P = 0.167), while IRIS lymphoma exhibited a survival rate similar to lymphoma off ART (P = 0.618). In Korean HIV-positive patients, there were significantly more cases of Hodgkin lymphoma of a less advanced stage in non-IRIS lymphoma on ART than in lymphoma off ART, in contrast to IRIS lymphoma.

Radiotherapy as an effective treatment modality for follicular lymphoma: a single institution experience

Purpose

Follicular lymphoma (FL) is an indolent non-Hodgkin's lymphoma that is highly sensitive to radiotherapy (RT). However, the effectiveness of RT has not been well established. We reviewed our experiences to assess the role of RT for FL and analyze treatment results.

Materials and Methods

Retrospective analysis was done on 29 patients who received first RT between January 2003 and August 2013. Of 23 early stage (stage I, II) patients, 16 received RT alone, four received chemotherapy followed by RT, two received RT postoperatively, and one received salvage RT for relapse after resection. Six advanced-stage (stage III, IV) patients received RT after chemotherapy: two received consolidation RT, three received salvage RT for residual lesions, and one received RT for progressive sites. Median RT dose was 30.6 Gy (range, 21.6 to 48.6 Gy). Median follow-up duration was 62 months (range, 6 to 141 months).

Results

All patients showed complete response in the radiation field. Eight outfield relapses were reported. Seven patients received salvage treatment (three chemotherapy, four RT). Four patients showed excellent responses, especially to RT. Estimated 5-year and 10-year relapse-free survivals were 72% and 60%. In the RT-alone group, 5-year relapse-free survival was 74.5%. All advanced-stage patients were disease-free with 100% 5-year overall survival. Disease-specific death was noted in only one patient; four others died of other unrelated causes. No significant toxicity was reported.

Conclusion

RT resulted in excellent treatment outcomes for all FL stages when used as a primary treatment modality for early stage or salvage-treatment modality for advanced-stage disease.

A Rare Case of Malignant Lymphoma Occurred at Spinal Epidural Space: A Case Report

The sacral spinal epidural space is an uncommon site for primary malignant lymphomas, presenting with symptoms associated with cauda equina compression. Especially, lumbo-sacral epidural lymphoma has been reported to be very rare. We present a rare case of 29-year-old male with sacral spinal epidural malignant lymphoma. The patient complained of tingling sensation in his buttocks that was radiating to his calf. The neurological examination was normal. Magnetic resonance imaging (MRI) with contrast showed a well-defined extradural mass lesion at the mid L5 to mid S2 level. The lesion was iso- to hypointense on T1 and T2 weighted images and showed homogenous enhancement and a focal enhancement in the L5 vertebral body on post-contrast images. The patient underwent a L5-S2 laminectomy and subtotal excision of the lesion. Intra-operatively, the lesion was extradural and not densely adherent to the dura; the lesion was friable, not firm, fleshy, brownish and hypervascular. The histologic diagnosis was grade 2 non-Hodgkin's follicular lymphoma. Even though the primary spinal epidural non-Hodgkin's lymphoma is a very rare disease, clinicians should take it into consideration in the differential diagnosis of patients with spinal epidural tumor.

Clinicopathologic Study of Chromosomal Aberrations in Ocular Adnexal Lymphomas of Korean Patients

Purpose

The incidence and clinical correlation of MALT1 translocation and chromosomal numerical aberrations in Korean patients with ocular adnexal mucosa associated lymphoid tissue (MALT) lymphoma have not yet been reported. We investigated the incidence and clinicopathologic relationship of these chromosomal aberrations in ocular adnexal MALT lymphomas in a Korean population.

Methods

Thirty ocular adnexal MALT lymphomas were investigated for the t(11;18) API2-MALT1, t(14;18) IgH-MALT1 translocations and chromosomes 3 and 18 aneuploidies using fluorescence in situ hybridization. Patient medical records were reviewed retrospectively for information on demographics and clinical characteristics, including treatment response.

Results

The MALT1 gene rearrangement was found in one out of 30 cases. The t(14;18) IgH-MALT1 translocation was demonstrated in only one case (3.3%), and the t(11;18) API2-MALT1 translocation was not found in any of the cases. Trisomy 3 was observed in three ocular adnexal MALT lymphomas (10.0%), and five cases showed trisomy 18 (16.7%). Translocation positive cases also showed trisomy 18. One case of tumor relapse showed trisomy 18 only in the recurrent biopsies. There were no statistically significant correlations between chromosomal aberrations and clinical characteristics and treatment responses.

Conclusions

Translocations involving the MALT1 gene are not common in Korean ocular adnexal MALT lymphomas. The t(14;18) translocation was detected in only one out of 30 cases, and the t(11;18) translocation was not found at all. Furthermore, the chromosomal aberrations found in this study had no prognostic implications.

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders

Primary infection with Epstein-Barr virus (EBV) is usually asymptomatic and, in a normal host, EBV remains latent in B cells after primary infection for the remainder of life. Uncommonly, EBV can infect T or natural killer (NK) cells in a person with a defect in innate immunity, and EBV infection can cause unique systemic lymphoproliferative diseases (LPD) of childhood. Primary infection in young children can be complicated by hemophagocytic lymphohistiocytosis or fulminant systemic T-cell LPD of childhood. Uncommonly, patients can develop chronic active EBV (CAEBV) disease-type T/NK LPD, which includes CAEBV infection of the systemic form, hydroa vacciniforme-like T-cell LPD, and mosquito-bite hypersensitivity. The clinical course of CAEBV disease-type T/NK LPD can be smoldering, persistent or progressive, depending on the balance between viral factors and host immunity. Aggressive NK-cell leukemia, hydroa vacciniforme-like T-cell lymphoma, or uncommonly extranodal NK/T-cell lymphoma can develop in children and young adults with CAEBV disease-type T/NK-cell LPD. Extranodal T/NK-cell lymphoma is a disease of adults, and its incidence begins to increase in the third decade and comprises the major subtype of T/NK LPD throughout life. Aggressive NK-cell leukemia and nodal T/NK-cell lymphoma of the elderly are fulminant diseases, and immune senescence may be an important pathogenetic factor. This review describes the current progress in identifying different types of EBV-associated T/NK-cell LPD and includes a brief presentation of data from Korea.

Overexpression of sphingosine-1-phosphate receptor 1 and phospho-signal transducer and activator of transcription 3 is associated with poor prognosis in rituximab-treated diffuse large B-cell lymphomas

Background

Sphingosine-1-phosphate receptor-1 (S1PR1) and signal transducer and activator of transcription-3 (STAT3) play important roles in immune responses with potential oncogenic roles.

Methods

We analyzed S1PR1/STAT3 pathway activation using immunohistochemistry in rituximab-treated diffuse large B-cell lymphomas (DLBCL; N = 103).

Results

Nuclear expression of pSTAT3 (but not S1PR1) was associated with non-GCB phenotype (p = 0.010). In univariate survival analysis, S1PR1 expression (S1PR1+) was a poor prognostic factor in total DLBCLs (p = 0.018), as well as in nodal (p = 0.041), high-stage (III, IV) (p = 0.002), and high-international prognostic index (IPI; 3–5) (p = 0.014) subgroups, while nuclear expression of pSTAT3 (pSTAT3+) was associated with poor prognosis in the low-stage (I, II) subgroup (p = 0.022). The S1PR1/pSTAT3 risk-categories, containing high-risk (S1PR1+), intermediate-risk (S1PR1-/pSTAT3+), and low-risk (S1PR1-/pSTAT3-), predicted overall survival (p = 0.010). This prognostication tended to be valid in each stage (p = 0.059 in low-stage; p = 0.006 in high-stage) and each IPI subgroups (p = 0.055 [low-IPI]; p = 0.034 [high-IPI]). S1PR1 alone and S1PR1/pSTAT3 risk-category were significant independent prognostic indicators in multivariate analyses incorporating IPI and B symptoms (S1PR1 [p = 0.005; HR = 3.0]; S1PR1/pSTAT3 risk-category [p = 0.019: overall; p = 0.024, HR = 2.7 for S1PR1-/pSTAT3+ vs. S1PR1+; p = 0.021, HR = 3.8 for S1PR1-/pSTAT3- vs. S1PR1+]).

Conclusions

Therefore, S1PR1 and S1PR1/pSTAT3 risk-category may contribute to risk stratification in rituximab-treated DLBCLs, and S1PR1 and STAT3 might be therapeutic targets for DLBCL.

Characteristics of Cutaneous Lymphomas in Korea According to the New WHO-EORTC Classification: Report of a Nationwide Study

Background

Previously, cutaneous lymphomas were classified according to either the European Organization for the Research and Treatment of Cancer (EORTC) or the World Health Organization (WHO) classification paradigms. The aim of this study was to determine the relative frequency of Korean cutaneous lymphoma according to the new WHO-EORTC classification system.

Methods

A total of 517 patients were recruited during a recent 5 year-period (2006-2010) from 21 institutes and classified according to the WHO-EORTC criteria.

Results

The patients included 298 males and 219 females, and the mean age at diagnosis was 49 years. The lesions preferentially affected the trunk area (40.2%). The most frequent subtypes in order of decreasing prevalence were mycosis fungoides (22.2%), peripheral T-cell lymphoma (17.2%), CD30+ T-cell lymphoproliferative disorder (13.7%), and extranodal natural killer/T (NK/T) cell lymphoma, nasal type (12.0%). Diffuse large B-cell lymphoma accounted for 11.2% of cases, half of which were secondary cutaneous involvement; other types of B-cell lymphoma accounted for less than 1% of cases.

Conclusions

In comparison with data from Western countries, this study revealed relatively lower rates of mycosis fungoides and B-cell lymphoma in Korean patients, as well as higher rates of subcutaneous panniculitis-like T-cell lymphoma and NK/T cell lymphoma.

Current concepts in primary effusion lymphoma and other effusion-based lymphomas

Primary effusion lymphoma (PEL) is a human herpes virus 8 (HHV8)-positive large B-cell neoplasm that presents as an effusion with no detectable tumor in individuals with human immunodeficiency virus infection or other immune deficiencies. PEL is an aggressive neoplasm with a poor prognosis. PEL cells show diverse morphologies, ranging from immunoblastic or plasmablastic to anaplastic. The immunophenotype of PEL is distinct, but its lineage can be misdiagnosed if not assessed thoroughly. PEL cells usually express CD45, lack B- and T-cell-associated antigens, and characteristically express lymphocyte activation antigens and plasma cell-associated antigens. Diagnosis of PEL often requires the demonstration of a B-cell genotype. HHV8 must be detected in cells to diagnose PEL. In most cases, PEL cells also harbor the Epstein-Barr virus (EBV) genome. Similar conditions associated with HHV8 but not effusion-based are called "extracavitary PELs." PELs should be differentiated from HHV8-negative, EBV-positive, body cavity-based lymphomas in patients with long-standing chronic inflammation; the latter can occur in tuberculous pleuritis, artificial pneumothorax, chronic liver disease and various other conditions. Despite their morphological similarity, these various lymphomas require different therapeutic strategies and have different prognostic implications. Correct diagnosis is essential to manage and predict the outcome of patients with PEL and related disorders.

The role of radiotherapy in the treatment of gastric mucosa-associated lymphoid tissue lymphoma

Purpose

To assess radiotherapy for patients with early stage gastric mucosa-associated lymphoid tissue (MALT) lymphoma with respect to survival, treatment response, and complications.

Materials and Methods

Enrolled into this study were 48 patients diagnosed with gastric MALT lymphoma from January 2000 to September 2012. Forty-one patients had low grade and seven had mixed component with high grade. Helicobacter pylori eradication was performed in 33 patients. Thirty-four patients received radiotherapy alone. Ten patients received chemotherapy before radiotherapy, and three patients underwent surgery followed by chemotherapy and radiotherapy. One patient received surgery followed by radiotherapy. All patients received radiotherapy of median dose of 30.6 Gy.

Results

The duration of follow-up ranged from 6 to 158 months (median, 48 months). Five-year overall survival and cause-specific survival rates were 90.3% and 100%. All patients treated with radiotherapy alone achieved pathologic complete remission (pCR) in 31 of the low-grade and in three of the mixed-grade patients. All patients treated with chemotherapy and/or surgery prior to radiotherapy achieved pCR except one patient who received chemotherapy before radiotherapy. During the follow-up period, three patients developed diffuse large B-cell lymphoma in the stomach, and one developed gastric adenocarcinoma after radiotherapy. No grade 3 or higher acute or late complications developed. One patient, who initially exhibited gastroptosis, developed mild atrophy of left kidney.

Conclusion

These findings indicate that a modest dose of radiotherapy alone can achieve a high cure rate for low-grade and even mixed-grade gastric MALT lymphoma without serious toxicity. Patients should be carefully observed after radiotherapy to screen for secondary malignancies.

Clinical features and survival outcomes of patients with diffuse large B-cell lymphoma: analysis of web-based data from the Korean Lymphoma Working Party Registry

BACKGROUND

This study aimed to survey the clinical spectrum of diffuse large B-cell lymphoma (DLBCL) in terms of epidemiology, pathologic subtypes, stage, and prognostic index as well as treatment outcomes.

METHODS

In 2007-2008, 13 university hospitals evenly distributed in the Korean peninsula contributed to the online registry of DLBCL at www.lymphoma.or.kr and filed a total of 1,665 cases of DLBCL recorded since 1990.

RESULTS

Our analysis showed a higher prevalence of DLBCL in male than in female individuals (M:F=958:707), and extranodal disease was more common than primary nodular disease (53% vs. 47%). Among the 1,544 patients who had been treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or rituximab-CHOP (R-CHOP) therapy with or without radiation, 993 (63.9%) were alive, with 80% free of disease, 417 were dead (26.8%), with 13% free of disease, and 144 (9.3%) were lost to follow-up, with 23% free of disease. Age below 60 years, stage at diagnosis, international prognostic index (IPI) score regardless of age, and addition of rituximab to CHOP therapy in low- and low-intermediate-risk groups according to IPI scores significantly increased survival duration.

CONCLUSION

The epidemiology, clinical spectrum, and biological behavior of DLBCL in Korea are similar to those observed in Western countries, and the advent of rituximab improved survival.

Clinicopathologic implication of A20/TNFAIP3 deletion in diffuse large B-cell lymphoma: an analysis according to immunohistochemical subgroups and rituximab treatment

We analyzed the clinicopathologic implication of A20/tumor necrosis factor α-induced protein 3 deletion in diffuse large B-cell lymphoma (DLBCL) using fluorescence in situ hybridization, according to germinal center B-cell (GCB) versus non-GCB/activated B-cell (ABC) phenotypes and rituximab treatment. Excluding primary central nervous system (CNS) and Epstein-Barr virus (EBV)-positive lymphomas, 134 DLBCLs were analyzed. A20 was deleted in 23.1% (31/134) of DLBCLs including 21.6% (29/ 134) of monoallelic and 1.5% (2/134) of biallelic deletion, with no predilection for GCB versus non-GCB/ABC. In univariate analysis, A20 deletion was marginally associated with favorable prognosis in the rituximab-treated subgroup (n = 109; p = 0.0454), non-gastrointestinal lymphoma (n = 108; p = 0.0320) and nodal lymphoma (n = 46; p = 0.0411). In multivariate analysis in rituximab-treated DLBCL, MUM1 and international prognostic index (IPI) were independent prognostic factors (p = 0.021 [IPI]; p = 009 [MUM1]) with a marginally favorable prognostic effect for A20 deletion (p = 0.047). Taken together, A20 deletion was observed in similar frequencies in GCB and non-GCB/ABC, and was not a poor prognostic factor in DLBCL.

Epidemiologic overview of malignant lymphoma

Malignant lymphoma encompasses a wide variety of distinct disease entities. It is generally more common in developed countries and less common in developing countries. The East Asia region has one of the lowest incidence rates of malignant lymphoma. The incidence of malignant lymphoma around the world has been increasing at a rate of 3-4% over the last 4 decades, while some stabilization has been observed in developed countries in recent years. The reasons behind this lymphoma epidemic are poorly understood, although improving diagnostic accuracy, the recent AIDS epidemic, an aging world population and the increasing adoption of cancer-causing behaviors are suggested as contributing factors. Etiologies of malignant lymphoma include infectious agents, immunodeficiency, autoimmune disease, exposure to certain organic chemicals, and pharmaceuticals. The distribution of many subtypes exhibit marked geographic variations. Compared to the West, T/natural killer (NK) cell lymphomas (T/NK-cell lymphoma) and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are relatively more common, whereas other B-cell lymphomas, particularly follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, are less common in Asia. Some subtypes of T/NK-cell lymphomas defined by Epstein-Barr virus association are predominantly Asian diseases, if not exclusively so. Both ethnic and environmental factors play roles in such diversity. In this review, we discuss the geographic distribution and etiology of malignant lymphoma, as well as the trend.