We examined the outcome of treatment with first-line chemotherapy with bevacizumab(Bmab)formetastatic colorectal cancer in our hospital to clarify the outcome for RAS mutant patients.

Programmed cell death 1(PD-1)/PD-ligand 1(PD-L1)immune checkpoint blockade has emerged as a promising therapeutic strategy in various types of cancer. In a recent phase II clinical trial, treatment with the anti-PD-1 agent, pembrolizumab, resulted in considerable clinical benefit in patients with mismatch repair(MMR)-deficient colorectal cancer(CRC). Upregulation of PD-1on T-cells and PD-L1 on tumor cells induces inhibitory signals to suppress T-cell activation, leading to an immune-suppressive microenvironment particularly in MMR-deficient tumors. However, the regulation of PD-L1 expression on CRC cells is poorly understood. We hypothesized that certain microRNAs(miRNAs)are involved in the immunosuppressive microenvironment by directly targeting PD-L1. We identified candidate miRNAs by RNA-sequence analyses for mRNA and miRNA expression obtained from the TCGA colon adenocarcinoma database combined with miRNA target prediction programs. We found that forced miRNA expression could decrease PD-L1 expression on cancer cell lines. Our findings may facilitate an understanding of the role of miRNAs in PD-L1 regulation and also suggest potential miRNAs to serve as biomarkers and therapeutic targets for cancer immunotherapy.

Cancer Clinical Sequencing is a method for making the treatment decision for each cancer patient. Implication of the clinical sequencing is rapidly in progress in Japan. In general, the tumor FFPE samples obtained by biopsy or operatory resection are subjected to amplicon sequencing. The process was divided into pre-analysis, analysis, and post-analysis processes. Quality assurance and control are necessary for all process. In addition, the expert members for clinical sequencing team is essential to make clinical sequencing reports based on the NGS analysis.

In the 2016 revision of the World Health Organization (WHO) classification, the categories of myeloid neoplasms have not been revised significantly from the 2008 fourth edition. However, recent discovery of molecular abnormalities provides a new perspective regarding the diagnostic and prognostic markers. In myeloproliferative neoplasms, the identification of CALR gene mutation, in addition to the JAK2 and MPL mutations, has impacted the diagnostic criteria. In myelodysplastic syndromes and acute myeloid leukemia, in addition to alterations in the transcription factors and signal transduction pathways, discovery of gene mutations in the epigenetic regulators that are involved in DNA methylation, histone modification, cohesin complex, and RNA splicing, by comprehensive genetic analyses, has improved our understanding of the pathobiology of these diseases. Moreover, recent large-scale sequencing studies have revealed the acquisition of clonal somatic mutations, in the myeloid neoplasm-associated genes of the hematopoietic cells. Such mutations were detected in people with normal blood cell counts, without any apparent disease. Presence of these mutations confers an increased risk for subsequent hematological neoplasms, indicating the concept of clonal hematopoiesis of indeterminate potential. This updated WHO classification incorporates the criteria of new clinical, prognostic, morphologic, immunophenotypic, and genetic findings in myeloid neoplasms.

Both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are common malignant diseases in adolescents and young adults (AYAs). Recent advances in genomic studies have helped us understand the biological nature of acute leukemia in AYAs; higher frequency of Ph-like ALL and rearrangements in DUX4, ERG, MEF2D, and ZNF384 genes in AYAs with ALL and higher frequency of FLT3-ITD, NPM1, IDH1/2, DNMT3A, ASXL1, TET2, and CEBPA mutations in AYAs with AML than that in children. The pediatric-inspired regimen has become a standard treatment approach for AYAs with ALL, but optimal treatment strategy for AYAs with AML is not yet established to date. In general, poor adherence to the pediatric-inspired regimen, whether for ALL or AML, because of toxicities is still an issue in AYAs. In addition to optimizing appropriate chemotherapies for acute leukemia in AYAs, the development of novel therapy based on genomic analyses should be explored by close cooperation between pediatric hematologists/oncologists and adult hematologists.

Diffuse large B-cell lymphoma (DLBCL) represents the most common subtype of non-Hodgkin lymphoma, accounting for 30%-40% of all types of malignant lymphoma. Importantly, two distinct molecular subtypes, germinal center B-cell (GCB) type and activated B-cell (ABC) type, arising from B lymphocyte differentiation based on the gene expression profiling opened doors to uncover molecular pathogenesis in DLBCL. Since 2010, next-generation sequencing analyses have been revealing the landscape of genetic mutations in DLBCL. Reportedly, GCB DLBCL is characterized by the accumulation of genetic abnormalities of epigenetic modifiers. Conversely, the hallmark of ABC DLBCL is the constitutive activation of the NKκB signaling pathway due to mutations in related genes. From recent prospective trials, conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) regimen, which is the current standard regimen for DLBCL, has been acknowledged as a well-established regimen for DLBCL. Currently, the development of a plethora of drugs targeting the activated signaling pathway and immune microenvironments is ongoing. To overcome this intractable disease with the present treatment, the breakthroughs based on molecular pathogenesis are required.

The introduction of new agents and hematopoietic stem cell transplantation into the treatment of ATL has activated its clinical research. However, the prognosis of ATL remains poor compared with those of other leukemias and lymphomas. Thus, seemingly we have to reconsider a new strategy of ATL therapy based on its unique characteristics. HTLV-1 infection of T cells results in clonal proliferation of infected cells that accumulate genetic and epigenetic abnormalities before the onset of ATL. Therefore, the treatment strategy should include the prevention of HTLV-1 infection and ATL development in addition to precision medicine based on the stratification of ATL cases by biomarkers that discriminate clinical stages of ATL. I summarize here the recent progress in ATL research focusing on the biomolecular abnormalities that lead to clonal expansion and malignant transformation of HTLV-1-infected T cells. Apparently, one of the bases for the prevention of ATL is to establish a disease entity of "chronic active HTLV-1 infection" that defines high-risk carriers for ATL development and enables preventive intervention.

Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell malignancy caused by human T-lymphotropic virus type I (HTLV-1). HTLV-1 related proteins Tax and HTLV-1 bZIP factor induce immortalization and transformation of HTLV-1-infected T-lymphocytes and eventually induce clonal proliferation. One of the apparent molecular features in ATL cells is abundant genomic abnormalities targeting characteristic pathways, including T-cell receptor signaling and the NF-κB pathway, G-protein coupled-receptor, including CCR4, and transcriptional regulation. Moreover, the overexpression of PD-L1 caused by structural variations in the 3'-UTR of the PD-L1 gene has been reported recently, which indicates possible escape of ATL cells from immune-surveillance and its therapeutic application for pharmacological intervention. The next is the downregulation of microRNAs and tumor suppressors by genome-wide epigenetic abnormalities, especially accumulation of trimethylated H3K27 induced by EZH2. Among these molecular events frequently observed in ATL cells, treatment targeting CCR4 via a monoclonal antibody has been introduced in the clinic, and immune-therapy by therapeutic vaccine with Tax peptide-pulsed dendritic cells, treatment by immune checkpoint inhibitors, and treatment targeting EZH1/2 by a small molecule inhibitor are under clinical trial. Establishment of novel treatment strategies beyond cytotoxic agents for ATL are eagerly anticipated, especially for elderly patients.

Chronic lymphocytic leukemia (CLL) is characterized by clonal proliferation and accumulation of mature CD5-positive, CD10-negative, CD20 weakly positive, and CD23-positive B-cells within blood, bone marrow, lymph nodes, and spleen. In proliferation centers, the survival and growth of CLL cells requires a permissive microenvironment comprising T-cells, macrophages, and stromal cells. FISH analysis has revealed that almost 80% of CLL cases carry chromosomal abnormalities including the most frequent del (13q14) and the strongest poor prognostic factor del (17p), both related to TP53 mutations. Current treatment approaches are not curative for CLL, except allogeneic hematopoietic stem cell transplantation, which is rarely offered to the majority of patients aged 70 years and older. Currently, there is no evidence that the initiation of therapy for asymptomatic early-stage disease improves the overall survival, even for patients with high-risk disease. The identification that the B-cell receptor (BCR) signaling pathway is aberrantly and constitutively activated in CLL has recently led to the development of BCR signaling inhibitors, ibrutinib and idelalisib. In addition, a novel BCL-2 antagonist, venetoclax, appears promising when used alone or in combination with anti-CD20 antibodies. The advent of novel small-molecule inhibitors has revolutionized the treatment approaches for patients with CLL.

Since the development of imatinib mesylate, an ABL tyrosine kinase inhibitor (TKI), the treatment of chronic myeloid leukemia (CML) has made remarkable progress. Second and third generation TKIs have also become available for clinical use. Considering the improved treatment outcomes, chronic phase CML has become manageable, with a low mortality rate. Furthermore, clinical trials such as STIM and DADI have shown that TKI can be discontinued safely in certain CML patients. However, some CML patients, especially those in accelerated phase (AP) or blast phase (BP), require more aggressive forms of treatment such as allogenic hematopoietic stem cell transplantation. Next-generation sequencing technology and other novel technologies allow us to investigate the cause of CML and the molecular biology of progression to AP/BP in more detail. Based on these data, an increasing number of novel therapeutic agents for CML are being developed, which will improve the prognosis of CML.

Next generation sequencing (NGS) of cancer genomes is now becoming a prerequisite for accurate diagnosis and proper treatment in clinical oncology. Because the genomic regions for NGS expand from a certain set of genes to the whole exome or whole genome, the resulting sequence data becomes incredibly enormous and makes it quite laborious to translate the genomic data into medicine, so-called annotation and curation. We organized a clinical sequencing team and established a bidirectional (bed-to-bench and bench-to-bed) system to integrate clinical and genomic data for hematological malignancies. We also started a collaborative research project with IBM Japan to adopt the artificial intelligence Watson for Genomics (WfG) to the pipeline of medical informatics. Genomic DNA was prepared from malignant as well as normal tissues in each patient and subjected to NGS. Sequence data was analyzed using an in-house semi-automated pipeline in combination with WfG, which was used to identify candidate driver mutations and relevant pathways from which applicable drug information was deduced. Currently, we have analyzed more than 150 patients with hematological disorders, including AML and ALL, and obtained many informative findings. In this presentation, I will introduce some of the achievements we have made so far.

Despite recent progress in diagnosis and leukemogenesis based on genomic landscapes in acute myelogenous leukemia (AML), advances in AML treatment lag behind. Over the past four decades, combination chemotherapy with anthracycline and cytarabine remains the standard induction therapy. Subsequent post-remission consolidation therapy stratifies patients into favorable-risk, intermediate-risk, and unfavorable-risk groups to assign post-remission therapies based on cytogenetic abnormalities and molecular mutations. Allogeneic stem-cell transplant decreases the risk of AML recurrence compared to standard chemotherapy, but it also raises the risk of serious complications. Recent large collections of matched genomic and clinical data may assist in selecting the best individualized therapy for each AML patient. Emerging evidence indicates that molecularly targeted therapies such as FLT3 and IDH inhibitors may be effective in distinct AML subtypes, providing further rationale for a personalized medicine approach. An umbrella trial, such as "BEAT AML Master Trial," designed to offer novel targeted therapy to AML patients based on their genetic characteristics, will be launching worldwide in the near future.

The World Health Organization (WHO) classification of tumors of the hematopoietic and lymphoid tissues was last updated in 2008. The study of cancer genomes has identified inherited genetic drivers that predispose cancer cells to clonal evolution. The revisions in the categories of myeloid neoplasms and acute leukemia were published as a monograph in 2016. We described familial hematological malignancies using the 2016 edition of the WHO classification.

Recent clinical evidence that anti-PD-1/PD-L1 antibody therapy is superior to cytotoxic chemotherapy for patients with non-small cell lung cancer(NSCLC)that expresses PD-L1 has lead to a paradigm shift in treatment strategies for those patients. However, efficacy of anti-PD-1/PD-L1 antibodies for patients with NSCLC harboring EGFR mutation is generally poor. This lack ofresponse is at least partially attributed to suppression oftumor infiltrating lymphocytes caused by EGFR pathway activation or to low non-synonymous mutation load in NSCLC with EGFR mutation. However, anti-PD-1/PD-L1 antibodies may play some roles in patients who acquired resistance against EGFR tyrosine kinase inhibitors. In this review, relationship between patients with EGFR mutation and treatment using immune-checkpoint inhibitors is summarized.

Acute myeloid leukemia (AML) is a genetically heterogeneous disease, and its prognosis is stratified on the basis of chromosomal and genetic alterations. Core binding factor (CBF) leukemia consists of AML with t (8;21) (p22;q22) and inv16 (q16q16) /t (16;16) (q16;q16) and is included in AML with recurrent genetic abnormality according to WHO classification. Although CBF-AML is categorized as favorable-risk AML, approximately 40% of patients show relapse. The t (8;21) and inv16 (q16q16) /t (16;16) (q16;q16) result in RUNX1-RUNX1T1 and CBFB-MYH11 fusion genes, respectively; however, the fusion proteins encoded by these genes alone are insufficient for the development of leukemia. Activating kinase mutations in KIT, FLT3, and N-RAS have been frequently found, and their cooperation with RUNX1-RUNX1T1 or CBFB-MYH11 is thought to be crucial for leukemogenesis in CBF-AML. Recently, mutations in ASXL2, ZBTB7A, CCND2, and DHX15 have been frequently identified in t (8;21) AML, but their biological and clinical significance have not been elucidated. Thus, a combination of several genetic alterations is associated with the development of CBF-AML, and comprehensive genetic analysis is necessary for the stratification of this leukemia. CBF-AML is a still heterogeneous disease entity, and it is necessary to elucidate the combinations of genomic abnormalities and clonal evolutions for better understanding of the disease and to develop a new treatment strategy.

Annually, it is estimated that approximately 150-200 children aged 0-16 years are diagnosed with acute myeloid leukemia (AML). In Japan, clinical studies with ANLL91, AML99, CCLSG-AML9805, and JPLSG-AML05 protocols were performed historically, and the risk stratification with a combination of chemotherapy and hematopoietic stem cell transplantation resulted in the improvement of clinical outcomes. Regarding the onset of pediatric AML at the molecular level, mutations in FLT3-ITD or KIT (Class I mutation) showed a poor prognosis, but the ratio of mutations in Class III-V genes was smaller than that in adult AML. In contrast, several pediatric AML cases are complicated due to chromosome fragility syndrome or congenital bone marrow failure syndrome. To improve the clinical outcomes, clinical application of next generation sequencing may allow for personalized therapy in each patient in the future.

6-Mercaptopurine (6-MP) is one of the main components for the treatment of childhood acute lymphoblastic leukemia (ALL). However, many patients require a dose reduction of 6-MP due to its severe toxicities. NUDT15 variants are one of the factors that cause 6-MP intolerability in Asians. In each patient with heterozygous variants of NUDT15, 6-MP intolerability differs. Therefore, we hypothesized that the combination of NUDT15 genotype with ABCC4 genotype, which is associated with 6-MP efflux, might enable to accurately predict 6-MP intolerability. We analyzed the association between 6-MP-related events and the genotypes of NUDT15 and ABCC4. All patients with both NUDT15 rs116855232 heterozygous variants and ABCC4 rs3765534 variants suffered from severe leukopenia and required 6-MP dose reduction to less than 35 mg/m2/day. In conclusion, genotyping NUDT15 and ABCC4 facilitates the prediction of 6-MP intolerability. The results of this study will improve personalized medicines in Japanese patients with childhood ALL.

Based on various studies, the survival of adolescent and young adults (AYAs) with acute myeloid leukemia (AML) was reportedly similar to or worse than younger children. AYAs with AML treated in adult institutions are usually offered the same treatment as that of the older adults. Although pediatric protocols generally include intensified regimens compared with adult protocols, it is still controversial whether an intensified pediatric AML regimen results in an improved survival for the AYA population. Somatic mutations have proven to be significantly prognostic in AML. Although such molecular markers are becoming increasingly important as a means of risk stratification for both children and adults with AML, the prevalence and significance of somatic mutations remain largely unknown in AYAs with AML. In addition to the biological characteristics of cancer, non-biological factors, such as compliance with treatment, may influence the treatment outcomes of AYAs. AYAs have specific and unique needs that are different from children and older adults such as psychosocial care, transition from the pediatric to adult care environment, and fertility considerations among long-term survivors. A further multidisciplinary approach for AYAs with AML is still an issue among adult institutes.

Fusion genes found in cases of acute lymphoblastic leukemia (ALL) are reported to be associated with age, such as MLL rearrangements in neonates and BCR-ABL1 in adults. However, the pathogenesis of ALL in adolescents and young adults (AYA) remains largely unknown. To investigate the potential role of fusion genes, we performed RNA-sequencing on 73 BCR-ABL1-negative ALL patients who were all AYA. Interestingly, DUX4-IGH was the most frequent fusion gene detected in B-ALL (18.5%) and was preferentially detected in the AYA generation. ZNF384 and MEF2D genes were also recurrently identified as functionally relevant fusion genes in 16.7% and 9.3% of AYA with B-ALL, respectively. Patients with DUX4 and ZNF384 fusion genes displayed better prognosis, while those with the MEF2D fusion gene displayed a worse outcome. To improve treatment outcome, the fusion genes detected in this study will be useful for risk stratification and target therapy.

Patients with acute lymphoblastic leukemia (ALL) in adolescents and young adults (AYA) generation are treated by both pediatricians and adult hematologists. Because their participation rate in clinical trials has been low, the treatment results have been unsatisfactory. However, with a recent widespread adaptation of pediatric-based regimen in adult ALL trials, their prognosis has dramatically improved. Moreover, their characteristic biology is being rapidly elucidated. For further improvement of AYA-ALL prognosis and quality of life, the collaboration between pediatricians and adult hematologists is essential and multidisciplinary approach is necessary.