Epidemiology of malignant lymphoma and recent progress in research on adult T-cell leukemia/lymphoma in Japan

Cost drivers associated with autologous stem-cell transplant (ASCT) in patients with relapsed/refractory diffuse large B-cell lymphoma in a Japanese real-world setting: A structural equation model (SEM) analysis 2012-2022

Diffuse large B-cell lymphoma (DLBCL) is the most prevalent non-Hodgkin lymphoma, with increasing incidence, in Japan. It is associated with substantial economic burden and relatively poor survival outcomes for relapsed/ refractory (r/r) DLBCL patients. Despite its association with economic burden and the relatively limited number of eligible patients in Japan as reported in previous real-world studies, Japanese clinical guidelines recommend stem-cell transplantation (SCT) for transplant-eligible r/r DLBCL patients. This is the first study to elucidate the total healthcare cost, associated cost drivers and healthcare resource use of SCT among patients with r/r DLBCL in a nationwide setting. The study design included a follow-up period of up to 24 months with subsequent lines of therapies using retrospective nationwide claims data from the Medical Data Vision Co., Ltd. Health Insurance Association from April 2012 to August 2022. Included patients had a confirmed diagnosis of DLBCL, received allogeneic SCT (allo-SCT) or autologous SCT (ASCT) after the first DLBCL diagnosis, and received high-dose chemotherapy during the 6-month look-back period. The results confirmed that no patients had allo-SCT, hence only ASCT was included in the analysis. Structural equation modeling was used to identify potential total healthcare cost drivers by evaluating direct, indirect, and total effects and provide a benchmark reference for future innovative therapies. A total of 108 patients (3.8%) among all DLBCL patients who received SCT met the eligibility criteria and were considered ASCT patients; majority of which were males (n = 63, 58.33%), with a mean [median] (SD) age of 52.04 [55] (9.88) years. A total of 15 patients (13.89%) received subsequent therapies. The most frequent subsequent therapy was GDP-based with or without rituximab (n = 8, 7.41%). The mean [median] (SD) number of follow-up hospitalizations on or after SCT-related hospitalizations was 1.66 [1] (1.36), with a mean [median] (SD) length of hospital stay being 36.88 [34] (12.95) days. The total mean [median] (SD) healthcare cost after adjustment incurred per patient per year during follow-up was $79,052.44 [$42,722.82] ($121,503.65). Number of hospitalizations and Charlson Comorbidity Index scores (+5) were the key drivers of total healthcare costs in patients with r/r DLBCL. Index years 2020-2022 and heart disease as a complication were other statistically significant factors that had positive effects as increase on total healthcare costs.

Real-world assessment to estimate multiple attributes related to treatment cost driver for mantle cell lymphoma in Japan by econometric modeling

This study was conducted using a nationwide health care database of Japan between 1 April 2008 and 30 September 2022 to evaluate the economic burden on patients with mantle cell lymphoma (MCL). Structural equation modeling (SEM) is an advanced multivariate analysis framework used to assess the relationships between observed and latent variables within predefined causal models. In this study, SEM was employed to identify cost drivers and estimate variables related to MCL treatment cost. A total of 2,838 patients having at least one confirmed diagnosis of MCL participated in this study. As for the index regimen, a combination of bendamustine rituximab was the most frequently used (n = 328), followed by rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisolone-like regimen (n = 112), and others. The median of total health care cost (unadjusted and adjusted) were 32,228 USD and 31,918 USD, respectively. The mean (SD) of the frequency of bleeding treatment was 23 (35) per year, and that of outpatient visits was 19 (12) per year. SEM analysis revealed Bruton tyrosine kinase inhibitor-based treatment as a cost driver (β: 0.398 [0.340; 0.457], p < 0.001). Key health care resource utilization (HCRU) factors associated with an increased cost were the total length of hospitalization (β: 0.598 [0.551; 0.646], p < 0.001) and number of outpatient visits (β: 0.132 [0.083; 0.180], p < 0.001). This real-world study delivers insights for optimizing MCL care in Japan.

Steroid-resistant nephrotic syndrome as paraneoplastic syndrome of Waldenström macroglobulinemia: a case report

Reports of glomerulonephritis associated with lymphoproliferative disorders are common, but reports of minimal change disease (MCD) accompanying non-Hodgkin's lymphoma are rare. Here, we present a case of a 45-year-old woman diagnosed with primary Waldenström's macroglobulinemia (WM) during MCD treatment. Her kidney biopsy revealed endothelial cell injury in parts of the MCD. Subsequently, she developed steroid-resistant nephrotic syndrome and temporary acute kidney injury, requiring dialysis. Remission of the nephrotic syndrome was achieved after initiating combination therapy with bendamustine and rituximab for WM. The renal histological findings and treatment course suggest a causal relationship between MCD and WM in this case. The pathogenesis of MCD associated with WM may involve the release of glomerular permeability factors derived from B lymphocytes. Although mild WM is often managed with observation, steroid-resistant nephrotic syndrome associated with WM should raise suspicion of a paraneoplastic syndrome, necessitating active chemotherapy targeting WM as a critical treatment approach.

Cost-effectiveness analysis 3L of axicabtagene ciloleucel vs tisagenlecleucel and lisocabtagene maraleucel in Japan

Aim: Cost-effectiveness analysis (CEA) was performed to compare axicabtagene ciloleucel (axi-cel) with tisagenlecleucel (tisa-cel) and lisocabtagene (liso-cel) for treatment of relapsed or refractory large B-cell lymphoma in adult patients after ≥2 lines of therapy in Japan. Materials & methods: Cost-effectiveness analysis was conducted using the partition survival mixture cure model based on the ZUMA-1 trial and adjusted to the JULIET and TRANSCEND trials using matching-adjusted indirect comparisons. Results & conclusion: Axi-cel was associated with greater incremental life years (3.13 and 2.85) and incremental quality-adjusted life-years (2.65 and 2.24), thus generated lower incremental direct medical costs (-$976.29 [-¥137,657] and -$242.00 [-¥34,122]), compared with tisa-cel and liso-cel. Axi-cel was cost-effective option compared with tisa-cel and liso-cel from a Japanese payer's perspective.

Subcutaneous epcoritamab monotherapy in Japanese adults with relapsed/refractory diffuse large B-cell lymphoma

Epcoritamab is a subcutaneously administered CD3xCD20 bispecific Ab that showed deep, durable responses with a manageable safety profile in patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in the global multicenter pivotal phase II trial EPCORE NHL-1. Here, we present results from the similar EPCORE NHL-3 phase I/II trial evaluating epcoritamab monotherapy in Japanese patients with R/R CD20+ B-cell non-Hodgkin's lymphoma previously treated with two or more lines of therapy. Epcoritamab was dosed subcutaneously in 28-day cycles; once weekly during cycles 1-3, every 2 weeks during cycles 4-9, and every 4 weeks from cycle 10 until disease progression or unacceptable toxicity. Step-up dosing and cytokine release syndrome (CRS) prophylaxis were used during treatment cycle 1. As of January 31, 2022, 36 patients received treatment with 48 mg epcoritamab monotherapy. At a median follow-up of 8.4 months, overall response and complete response rates by independent review committee were 55.6% and 44.4%, respectively. The median duration of response, duration of complete response, and overall survival were not reached at the time of data cut-off. The most common treatment-emergent adverse events of any grade were CRS (83.3%), injection-site reactions (69.4%), infections (44.4%), neutropenia (38.9%), hypokalemia (27.8%), and decreased lymphocyte count (25.0%). Cytokine release syndrome occurrence was predictable; events were primarily low grade (grade 1-2), all resolved, and none led to treatment discontinuation. These encouraging results are consistent with previous findings and support the ongoing clinical evaluation of epcoritamab for the treatment of R/R DLBCL, including in earlier treatment lines.

Investigation of the female infertility risk associated with anti-cancer therapy

Female infertility is a significant health issue worldwide with a rising incidence. Anti-cancer therapy is one of the most important reasons for increasing infertility. Although anti-cancer treatment increases the rate of survival, it decreases the quality of life through its side effects. The most substantial side effects are sexual dysfunction and infertility. Breast cancer is the most common cancer. The first-line treatment of breast cancer is chemotherapy by alkylating agents like cyclophosphamide, which leads to infertility. For instance, persistent chemotherapy-induced amenorrhea among breast cancer patients could affect almost half of the patients that undergo such therapy. However, some agents or therapeutic methods can ameliorate these intoxicating effects. Chemotherapy plus gonadotropin-releasing hormone agonist, in breast cancer patients, can not only improve overall survival but also reduce ovarian toxicity. Age plays an essential role in chemotherapy-induced amenorrhea. Chemotherapy at a younger age can reduce the risk of infertility. Gynecological cancers including uterine and ovarian cancer, which have high mortality rates, are the most related cancers to infertility. Surgery is the primary treatment of gynecological cancers. Studies demonstrated that fertility-sparing surgery is a better option than radical surgery. In addition, neoadjuvant chemotherapy is mostly a better option than primary cytoreductive surgery in terms of survival and fertility. Immune checkpoint inhibitors (ICIs) have recently played a major role in treating various cancer types. However, ICIs are associated with hypophysitis, which affects ovaries and can lead to infertility. There are some options for ovarian preservation such as embryo cryopreservation, oocyte cryopreservation, ovarian transposition, ovarian tissue cryopreservation, and ovarian suppression by GnRH agonists. Anti-müllerian hormone level can be utilized to monitor the ovarian reserve. Moreover, to avoid fertility loss, approaches such as using transplantation of human placenta mesenchymal stem cells, administrating anti-inflammatory agents and hormone therapy are under investigation.

Cost drivers associated with diffuse large B-cell lymphoma (DLBCL) in Japan: A structural equation model (SEM) analysis

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin’s lymphoma of increasing prevalence in Japan. However, patients with relapsed or refractory disease to first line treatment (rrDLBCL) have been found to shoulder greater economic burden and have poor survival with subsequent lines of therapy. The relative impact of individual patient attributes on total medical cost among patients with rrDLBCL receiving second or third line (2L/3L) therapy was assessed. Structural equation modelling was used to identify potential cost drivers of total medical costs incurred by treatment and procedures in a Japanese retrospective claims database. From the database, rrDLBCL patients on 2L or 3L of treatment were grouped into respective cohorts. The mean [median] (SD) total medical cost of care for the 2L cohort was 73,296.40 [58,223.11] (58,409.79) US dollars (USD) and 75,238.35 [60,477.31] (59,583.66) USD for the 3L cohort. The largest total effect on medical cost in both cohorts was length of hospital stay (LOS) (β: 0.750 [95%CI: 0.728, 0.772] vs β: 0.762 [95%CI: 0.729, 0.794]). Length of hospital stay and potential heart disease complications due to line of treatment were the primary drivers of total cost for patients who had received at least 2L or 3L therapy for rrDLBCL.

Phase 2 results of lisocabtagene maraleucel in Japanese patients with relapsed/refractory aggressive B-cell non-Hodgkin lymphoma

The autologous anti-CD19 chimeric antigen receptor (CAR) T-cell product, lisocabtagene maraleucel (liso-cel), is administered at equal target doses of CD8⁺ and CD4⁺ CAR⁺ T cells. This analysis assessed safety and efficacy of liso-cel in Japanese patients with relapsed or refractory (R/R) aggressive large B-cell lymphoma (LBCL) in Cohort 3 of TRANSCEND WORLD (NCT03484702). Liso-cel (100 × 10⁶ total CAR⁺ T cells) was administered 2-7 days after lymphodepletion. The primary efficacy endpoint was objective response rate (ORR; Lugano 2014 criteria) assessed by an independent review committee. Fourteen patients were enrolled; 10 received liso-cel infusion (median time to liso-cel availability, 23 days) and were evaluable at data cutoff (median follow-up, 12.5 months). Grade ≥ 3 treatment-emergent adverse events were neutropenia (90%), leukopenia (80%), anemia (70%), and thrombocytopenia (70%). All-grade cytokine release syndrome (CRS) was observed in 50% of patients, though no grade ≥3 CRS events were reported. Grade 1 neurological events occurred in 1 patient but were resolved without any intervention. Prolonged cytopenia (grade ≥ 3 at day 29) was reported for 60% of patients. The ORR was 70%, and complete response rate was 50%. The median duration of response was 9.1 months (95% confidence interval [CI], 2.1-not reached), and overall survival was 14.7 months (95% CI, 1.7-not reached). One patient diagnosed with central nervous system involvement after screening but before liso-cel infusion, responded to liso-cel. Liso-cel demonstrated meaningful efficacy and a manageable safety profile in Japanese patients with R/R LBCL.

Stem cell transplant for mantle cell lymphoma in Taiwan

Mantle cell lymphoma (MCL) is a B-cell lymphoma featuring an aggressive course and a progressive relapsing pattern. International guidelines recommend early consolidative autologous stem cell transplant (auto-SCT) for eligible patients while reserving allogeneic SCT (allo-SCT) as therapy for refractory cases. Since data describing the implementation of transplants in the Asian population with MCL are limited, we aimed to analyze post-SCT outcomes of 99 MCL patients from the Taiwan Bone Marrow Transplant Registry database. The median age was 56 years, and 11% of the patients had blastoid variant MCL. Ninety-four patients received auto-SCT, while 13 patients received allo-SCT, eight of which received allo-SCT after failing auto-SCT. Before auto-SCT, 52% of the patients were in their first complete remission (CR1). Overall, 37 patients (39%) relapsed after auto-SCT. The median post-auto-SCT progression-free survival and overall survival (OS) were 43.6 months and not reached, respectively. Blastoid variant MCL, transplant not received in CR1, and disease progression within 12 months post-auto-SCT independently predicted inferior OS in multivariable analysis. The median post-allo-SCT OS was 74 months. Two patients (15%) died of MCL recurrence post-allo-SCT. Three patients with refractory diseases were salvaged with ibrutinib or venetoclax to allo-SCT. Treatment strategies incorporating novel agents warrant further optimization.

Transformed Mycosis Fungoides with a Cytotoxic T-Cell Phenotype

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma and occasionally undergo large cell transformation (transformed MF, TMF), resulting in a poorer clinical outcome. We describe a case of TMF with an immunophenotypic shift. MF showed the CD4 + CD8- T-cell phenotype, while TMF exhibited the CD4-CD8 + T-cell phenotype. Moreover, TMF expressed cytotoxic markers of TIA1 and Granzyme B. A PCR analysis of T-cell receptor genes revealed peak sizes that were the same in both biopsies, indicating that these two lymphomas were derived from the same clone.

Economic burden in treated Japanese patients with relapsed/refractory large B-cell lymphoma

Aim: To understand the economic burden of relapsed and refractory large B-cell lymphoma patients in Japan treated with salvage chemotherapy. Patients & methods: Patients who received systemic therapy after first-line treatment were analyzed to assess its associated cost and resource use using a retrospective claims database. The impact of COVID-19 was assessed separately. Results & conclusion: This study identified 2927 and 1085 patients in the second- (2L) and third-line (3L) cohorts. The median ages for the 2L and 3L cohorts were 71 and 70 years, respectively, with Charlson Comorbidity Score of 3. A majority of the patients had limited stem cell transplant due to advanced age. Median lengths of inpatient stay for the 2L and 3L cohorts were 118 and 116 days, respectively. The majority of costs were attributed to inpatient costs, and limited COVID-19 impact was observed in this study.

Outcomes of high dose therapy and autologous haematopoietic stem cell transplantation for non-hodgkin lymphoma: A retrospective analysis in a resource-limited country

AIM

To retrospectively report the clinical outcomes of non-Hodgkin's Lymphoma (NHL) patients post high dose therapy (HDT) with autologous haematopoietic stem cell transplant (AHSCT) and determine whether upfront transplant, which is a first-line consolidative treatment with induction chemotherapy, would be a feasible modality in a resource-limited country.

METHODS

The medical records for NHL patients who had undergone HDT followed by AHSCT from October 1997 to November 2016 from two hospitals in Klang Valley, Malaysia were obtained from the medical record database and analysed retrospectively through statistical analysis.

RESULTS

A total of 148 patients were retrospectively identified post-AHSCT, where the majority of whom had B cell lymphoma (53.4%). Majority of patients (88.5%) were in complete remission before AHSCT. The overall survival (OS) and event-free survival (EFS) at 3 years were 68.9% and 60.8%, respectively. The major cause of death was disease progression at 73.9%, while transplant-related mortality was 15.2%, with a median follow-up period of 179.5 weeks.

CONCLUSION

Our study illustrates the promising outcomes of HDT with AHSCT in NHL patients in a resource-limited country. We recommend larger studies to be conducted in the future with a longer duration of follow-up to validate our findings.

The epidemiology of lymphoma in Jordan: A nationwide population study of 4189 cases according to World Health Organization classification system

OBJECTIVE/BACKGROUND

Lymphoma is a common human cancer that shows a variable geographic incidence worldwide. It is the fourth most common cancer in Jordan. Systemic reports of descriptive epidemiology on lymphoma from the Middle East are limited.

METHODS

A nationwide multi-institutional retrospective study was conducted covering all major hospitals and laboratories that provide diagnostic services. We collected data on all cases diagnosed with lymphoma between 2014 and 2019. The included variables were patients' age, gender, anatomic site, and the histologic type according to the World Health Organization classification system.

RESULTS

A total of 4189 cases were diagnosed with lymphoma. There was a statistically significant gender difference (p < .05), as 57.5% of patients were males. The peak incidence occurred at age 25-55 years. There were 1,652 (39%) cases of Hodgkin lymphoma (HL) and 2,537 (61%) of non-Hodgkin lymphoma (NHL), where nodular sclerosis (67%) and diffuse large B-cell lymphoma (53%) were the most common subtypes, respectively. The average age-adjusted incidence rates per 100,000 population were 8.01 for all lymphomas, 4.33 for NHL, and 3.16 for HL and all remained stable over the 6 years.

CONCLUSION

HL is the most common lymphoma in Jordan, with a percentage higher than most of reported studies in Asian and Western countries. It also shows a unimodal distribution of age-specific incidence rates, with a single peak in young adults. The incidence rate of HL is higher than Eastern countries but comparable to the West. In contrast, NHL demonstrates a lower incidence rate than Western countries but a similar distribution of subtypes, as mature T/natural killer-cell lymphomas were rare.

Epidemiology of HTLV-1 Infection and ATL in Japan: An Update

Adult T-cell leukemia-lymphoma (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) infection that often occurs in HTLV-1-endemic areas, such as Japan, the Caribbean islands, Central and South America, Intertropical Africa, and the Middle East. In Japan, the nationwide estimation of the number of HTLV-1 carriers was at least 1.08 million in 2006–2007. Furthermore, in 2016, the nationwide annual incidence of newly infected with HTLV-1 was first estimated to be 3.8 per 100,000 person-years based on the age-specific seroconversion rates of blood donors in almost all areas of Japan. The incidence rate was three times higher in women than in men, and it was estimated that at least 4,000 new HTLV-1 infections occur yearly among adolescents and adults in Japan. As well known that HTLV-1 infection alone is not a sufficient condition for ATL to develop. To date, a variety of molecular abnormalities and host susceptibilities have been reported as candidate progression factors for the development of ATL in HTLV-1-carriers. In particular, quite recently in Japan, a variety of immunosuppressive conditions have been recognized as the most important host susceptibilities associated with the development of ATL from HTLV-1-carrier status. Furthermore, in 2013–2016 in Japan, a new nationwide epidemiological study of ATL was conducted targeting patients newly diagnosed with ATL in 2010–2011, from which the most current knowledge about the epidemiological characteristics of Japanese patients with ATL was updated as follows: (1) continuing regional unevenness of the distribution of people with HTLV-1, (2) further aging, with the mean age at diagnosis being 67.5 years, (3) declining M/F ratio, (4) increase of the lymphoma subtype, (5) sex differences in subtype distribution, (6) age differences in subtype distribution, and (7) comorbidity condition. In particular, 32.2% of ATL patients had comorbid malignancies other than ATL. However, the number of deaths due to ATL in Japan has been relatively stable, at around 1,000 patients annually, without significant decline from 1999 to 2017. Because the current epidemiological evidence about HTLV-1 and ATL is insufficient, further epidemiological studies are required.

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.

Association of high levels of plasma OX40 with acute adult T-cell leukemia

OX40, a member of the tumor necrosis factor receptor (TNFR) superfamily, co-stimulates activated T cells following interaction with its own ligand OX40L. Human T-cell leukemia virus type-1 (HTLV-1) is an etiological agent of adult T-cell leukemia (ATL). ATL cells are known to express cell surface OX40; however, the level of soluble OX40 (sOX40) in blood samples from ATL patients is unknown. Quantitative enzyme-linked immune-sorbent assay (ELISA) showed that sOX40 levels were significantly higher in plasma from acute ATL patients than those from asymptomatic HTLV-1 carriers and healthy donors, and correlated with sCD25 levels and HTLV-1 proviral loads in peripheral blood mononuclear cells (PBMCs). Fresh PBMCs from acute ATL patients showed a higher percentage of OX40-positive cells compared with those from carriers, and shed sOX40 into culture supernatants. Shedding of sOX40 was partially inhibited by a matrix metalloproteinase (MMP) inhibitor, GM6001. A fraction of sOX40 was capable of binding to OX40L. These results suggest that high levels of sOX40 are shed into blood from a large number of ATL cells in acute ATL patients. Thus, abnormally elevated plasma sOX40 levels may be useful as an additional diagnostic marker of acute ATL.

A case of AITL complicated by EBV-positive B cell and monoclonal plasma cell proliferation and effectively treated with lenalidomide

Angioimmunoblastic T-cell lymphoma (AITL) is a common subtype of peripheral T-cell lymphoma with an aggressive clinical course and poor prognosis after conventional chemotherapy, for which there is no current standard of care. We describe here an 87-year-old woman with AITL, whose clinical diagnosis was complicated by the presence of B immunoblasts positive for Epstein-Barr virus in the lymph nodes and monoclonal plasma cells in the bone marrow at initial presentation. Rebiopsy of the lymph node led to the correct diagnosis of AITL with concurrent smoldering plasma cell myeloma. She was treated with several courses of conventional chemotherapy, resulting in progressive disease, and then switched to the immunomodulatory drug lenalidomide, which used in Japan for the treatment of multiple myeloma. Lenalidomide was effective in controlling both AITL and plasma cell myeloma.

Preventive Effects of Fermented Brown Rice and Rice Bran on Spontaneous Lymphomagenesis in AKR/NSlc Female Mice

Fermented brown rice and rice bran with Aspergillus oryzae (FBRA) is known to possess potentials to prevent chemical carcinogenesis in multiple organs of rodents. In the present study, possible chemopreventive effect of FBRA against spontaneous occurrence of lymphomas was examined using female AKR/NSlc mice. Four-week-old female AKR/NSlc mice were divided into three groups, and fed diets containing FBRA for 26 weeks at a dose level 0% (Group 1), 5% (Group 2) or 10% (Group 3). At the termination of experiment, the incidence of thymic malignant lymphoma of Group 3 was significantly lower than of Group 1 (p < 0.05). The average number of apoptotic cells of the thymic lymphoma of Group 3 was significantly larger than that of Group 1 (p < 0.05). In addition, the incidences of malignant lymphoma arising from body surface and abdominal lymph nodes, and the frequencies of lymphoma cell invasion to liver, kidney, spleen, and ovary of Group 3 were relatively lower than those of Group 1. These results indicate that FBRA inhibits spontaneous development of the lymphoma in female AKR/NSc mice and the inhibition of lymphomagenesis may relate to the induction of apoptosis by exposure of FBRA, suggesting that FBRA could be a protective agent against development of human lymphoma.

The clinical impact of human T-lymphotrophic virus type 1 (HTLV-1) infection on the development of adult T-cell leukemia-lymphoma (ATL) or HTLV-1-associated myelopathy (HAM) / atypical HAM after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and renal transplantation

Because there are limited clinical reports on the impact of human T-lymphotropic virus type 1 (HTLV-1) on organ transplantation, its effects on the development of adult T-cell leukemia-lymphoma (ATL), post-transplantation lymphoproliferative disorder (PTLD) and HTLV-1–associated myelopathy (HAM) or atypical HAM after organ transplantation remain unclear.

We retrospectively analyzed the impact of HTLV-1 in 54 allogeneic hematopoietic stem cell transplantation (allo-HSCT) cases and 31 renal transplantation cases between January 2006 and December 2016.

Among the 54 allo-HSCT cases, nine recipients with ATL tested positive for HTLV-1, and one was found to be an HTLV-1 carrier. All donors tested negative for HTLV-1. Only one HTLV-1 carrier did not present with ATL or HAM development after allo-HSCT. Among nine ATL cases after allo-HSCT, four eventually relapsed due to proliferation of recipient-derived ATL cells. However, in one ATL case, atypical HAM developed rapidly at 5 months after allo-HSCT.

Among the 31 renal transplantation cases, all donors tested negative for HTLV-1, and only recipients tested positive. Only one HTLV-1 carrier recipient did not present with ATL or HAM development after renal transplantation. However, one HTLV-1-negative recipient developed PTLD in the brain 10 years after renal transplantation.

In clinical practice, careful follow-up of HTLV-1 infected recipients after organ transplantation is important because atypical HAM can develop in ATL patients after allo-HSCT. Furthermore, to clarify the risk of ATL or HAM development in HTLV-1 infected recipients, we prospectively followed up our cohort.