Thrombotic complications are a major cause of death in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), which are closely associated with the JAK2 V617F activating mutation. However, whether the presence of the JAK2 V617F mutation affects thrombotic risk is currently unknown, although some reports have suggested a variable association with thrombosis. Therefore, we investigated the association between JAK2 V617F and various complications, including thrombosis, in Japanese patients with MPNs. We assessed the JAK2 V617F status in 140 patients who were diagnosed or doubted as having some type of MPN by utilizing a JAK2 V617F-specific guanine-quenching probe. JAK2 V617F was detected in 31 of 51 patients (60.8%) with essential thrombocythemia, all 16 patients (100%) with polycythemia vera, 4 of 11 patients (36.4%) with primary myelofibrosis, 2 of 18 patients (11.1%) with other types of MPNs, and none of the 44 patients with doubted MPN. In the 78 patients with classical MPN, JAK2 V617F correlated with a leukocyte count ≥10,000/μl (p=0.046). Complications of thrombosis, hemorrhage, and leukemic transformation occurred in 21 (41.2%), 4 (25.0%), and 3 (27.3%) patients with classical MPN, respectively, and thrombotic events (TE) occurred more frequently in patients with JAK2 V617F than without (p=0.047). Based on these findings, initial screening for the JAK2 mutation and careful monitoring for thrombotic events should be performed in patients with MPN.

Abstract.A 72-year-old Japanese male was diagnosed as having monoclonal gammopathy of undetermined significance and was followed up without therapy. Three years later, the patient progressed to symptomatic multiple myeloma. Melphalan + prednisolone was administered as first-line chemotherapy for ~6 years. Since the patient was judged to exhibit refractory multiple myeloma, he subsequently received radiation therapy on the lumbar spine. The patient was enrolled in a clinical trial and received lenalidomide + lowdose dexamethasone (Rd) therapy. The patient achieved very good partial remission following four cycles of Rd. At this time, large granular lymphocytes (LGLs) increased to 25-40% of peripheral blood leukocytes, however, the LGLs were present in the blood (~8%) prior to lenalidomide treatment. By flow cytometry of surface antigens, it was revealed that the LGLs were positive for cluster of differnetiation (CD)2, 7, 8, 16, 56, and 57, and human leukocyte antigen-D related, however, were negative for CD3, 4 and 5, suggesting that these LGLs predominantly exhibited an natural killer (NK) cell phenotype. T-cell receptor β gene rearrangement was not detected by polymerase chain reaction. A 51 Cr release assay was performed to investigate whether the NK cells actually possessed activity. A low level of M protein was sustained for ~15 months. This implied the enhancement of immune activation during lenalidomide treatment. The present case study suggested that LGL cells induced by lenalidomide may contribute to long-term restraint of myeloma cells. This immune system component may contribute to disease control.

Background/Aim: Trabectedin is a synthetic antineoplastic agent approved for advanced soft tissue sarcoma (STS) in Japan. The aim of this study was to evaluate the efficacy and safety of the Japan-approved dose of trabectedin for advanced STS. Patients and Methods: We retrospectively reviewed 38 patients with advanced STS who received salvage chemotherapy with trabectedin. Results: The overall response and disease control rates were 16% (5 patients) and 67% (20 patients), respectively. The median progression-free and overall survival were 7.3 and 17.8 months, respectively. There were no significant differences between patients with liposarcoma or leiomyosarcoma and those without, or between patients with TRS and those without. The most common grade 3-4 AEs were elevated transaminases and neutropenia. Conclusion: Trabectedin 1.2 mg/m 2 , as the approved dose in Japan, showed similar efficacy to the dose of 1.5 mg/m 2 used in Western countries. Trabectedin could be an option for advanced STS in Japan, regardless of histological subtype.

Mutation of the MYD88 has recently been identified in activated B cell like diffuse large B cell lymphoma (DLBCL) and enhanced cell proliferation systems such as JAK-STAT and NF-kB signaling pathways. However, much remains unclear about its clinical significance. In this study, we developed a highly sensitive and an automatic method utilizing guanine-quenching probes (QP) to detect mutation and investigated the relationship between MYD88 L265P mutation and clinical significance. We amplify a DNA fragment including the mutation to intend for by PCR and associate it with Q-probe with complementary sequence, using the temperature that Q-probe dissociates varying according to a conformity degree of the complementarity sequence. We judge it by detecting the fluorescence to be provided by dissociation. Results were obtained from 1ul of DNA solution(10ng) within 90 min by the method. Detected mutations were identical between QP method and allele-specific PCR (AS-PCR).Eighty-nine patients with a diagnosis of de novo DLBCL made between 1999 and 2014, and treated with CHOP or R-CHOP therapy. We retrospectively analyzed the outcome of 89 patients (age range; 21-88 and 59% were female). The median follow-up time was 4.4 y. Survival analyses were performed using the Kaplan-Meier method. None of the patients had a known history of human immunodeficiency virus infection. MYD88 L265P mutation was both assessed by Q-probe system that can detect low levels of mutant DNA and allele-specific TaqMan polymerase chain reaction assay. We performed the direct sequence method using 3130 Applied Biosystem Genetic Analyzer as antithesis. The cell-of-origin was determined based on immunohistochemical (IHC) stains for CD10, BCL-6 and MUM-1 by Hans' algorithm. MYD88 L265Pmutation was detected in 25.8% (23/89) in various tissues of DLBCL. MYD88 mutations occurred more frequently in males (P<0.05), cases without B symptoms (P<0.05). MYD88 mutation was infrequent in DLBCL arising in lymph nodes (10.6%), but more frequently found in extranodal sites such as testes (83%, 5/6), nasal (75%,9/12), central nervous system (50%,2/4), and leg (100%,1/1). In agreement with recent studies, we found no mutated cases among gastric cases. As somatic mutations in MYD88 was reported to be the most frequent alterations found in non-GCB type, we further analyzed GCB or non-GCB type by IHC. MYD88 mutations were predominantly observed in the non-GCB type (74%, 17/23), compared with 26%, 6/23 in GCB type. Overall survival (OS) for 3 years were 84.2% and 70.2% in patients with wild-type MYD88 and in MYD88 mutation group (P=0.366), respectively. Progression-free survival (PFS) for 3 years, 76.9% and 64.3% in patients with wild type and in mutated group (P=0.156), respectively. However, all four cases with CNS relapse had this mutation, 2 originated from testis, and remained 2 from lymph nodes. Our results confirm the remarkable site-specific occurrence of MYD88 mutation. In addition, Q-probe system for detection of MYD88 mutation was very useful because of its sensitivity and in the case who obtained only a small amount of biopsy specimen. MYD88 L265Ppromotes survival of malignant lymphoid cells through several mechanisms. Further large scale study should be necessary for more understanding of biological and clinical significance of DLBCL patients with MYD88 mutation. Disclosures No relevant conflicts of interest to declare.

Background/Aim: Trabectedin and eribulin are widely used for the treatment of soft-tissue sarcoma (STS). Previously it was shown that the baseline neutrophil-to-lymphocyte ratio (NLR) predicts the efficacy of eribulin for STS. However, prognostic factors for trabectedin on STS have not been identified to date. Patients and Methods: We conducted a retrospective study of data collected prospectively from 39 patients treated with trabectedin for recurrent or metastatic STS between October 2012 and December 2019. To determine the predictive factors of overall survival (OS) and progression-free survival (PFS), univariate and multivariate analyses were performed. Results: Age ≥40 (HR=0.33, 95% CI=0.15-0.71; p=0.0050) and changes in NLR (ΔNLR) <0.5 (HR=2.40, 95% CI-1.01-5.72; p=0.048) were independent factors predictive of longer OS. In addition, age ≥40 (HR=0.23, 95% CI=0.10-0.52; p<0.001) was an independent predictor of longer PFS. Conclusion: Changes in NLR and age ≥40 years were able to predict the efficacy of trabectedin for STS.