Clinical utility of genomic profiling of AML using paraffin-embedded bone marrow clots: HM-SCREEN-Japan 01.

Next-generation sequencing of AML has identified specific genetic mutations in AML patients. Hematologic Malignancies (HM)-SCREEN-Japan 01 is a multicenter study to detect actionable mutations using paraffin-embedded bone marrow (BM) clot specimens rather than BM fluid in AML patients for whom standard treatment has not been established. The purpose of this study is to evaluate the presence of potentially therapeutic target gene mutations in patients with newly diagnosed unfit AML and relapsed/refractory AML (R/R-AML) using BM clot specimens. In this study, 188 patients were enrolled and targeted sequencing was undertaken on DNA from 437 genes and RNA from 265 genes. High-quality DNA and RNA were obtained using BM clot specimens, with genetic alterations successfully detected in 177 patients (97.3%), and fusion transcripts in 41 patients (23.2%). The median turnaround time was 13 days. In the detection of fusion genes, not only common fusion products such as RUNX1-RUX1T1 and KMT2A rearrangements, but also NUP98 rearrangements and rare fusion genes were observed. Among 177 patients (72 with unfit AML, 105 with R/R-AML), mutations in KIT and WT1 were independent factors for overall survival (hazard ratio = 12.6 and 8.88, respectively), and patients with high variant allele frequency (≥40%) of TP53 mutations had a poor prognosis. As for the detection of actionable mutations, 38% (n = 69) of patients had useful genetic mutation (FLT3-ITD/TKD, IDH1/2, and DNMT3AR822 ) for treatment selection. Comprehensive genomic profiling using paraffin-embedded BM clot specimens successfully identified leukemic-associated genes that can be used as therapeutic targets.

Feasibility and clinical utility of comprehensive genomic profiling of hematological malignancies.

Identification of genetic alterations through next-generation sequencing (NGS) can guide treatment decision-making by providing information on diagnosis, therapy selection, and prognostic stratification in patients with hematological malignancies. Although the utility of NGS-based genomic profiling assays was investigated in hematological malignancies, no assays sufficiently cover driver mutations, including recently discovered ones, as well as fusions and/or pathogenic germline variants. To address these issues, here we have devised an integrated DNA/RNA profiling assay to detect various types of somatic alterations and germline variants at once. Particularly, our assay can successfully identify copy number alterations and structural variations, including immunoglobulin heavy chain translocations, IKZF1 intragenic deletions, and rare fusions. Using this assay, we conducted a prospective study to investigate the feasibility and clinical usefulness of comprehensive genomic profiling for 452 recurrently altered genes in hematological malignancies. In total, 176 patients (with 188 specimens) were analyzed, in which at least one alteration was detected in 171 (97%) patients, with a median number of total alterations of 7 (0-55). Among them, 145 (82%), 86 (49%), and 102 (58%) patients harbored at least one clinically relevant alteration for diagnosis, treatment, and prognosis, respectively. The proportion of patients with clinically relevant alterations was the highest in acute myeloid leukemia, whereas this assay was less informative in T/natural killer-cell lymphoma. These results suggest the clinical utility of NGS-based genomic profiling, particularly for their diagnosis and prognostic prediction, thereby highlighting the promise of precision medicine in hematological malignancies.

CDKN1C-mediated growth inhibition by an EZH1/2 dual inhibitor overcomes resistance of mantle cell lymphoma to ibrutinib.

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin's lymphoma, which is characterized by overexpression of cyclin D1. Although novel drugs, such as ibrutinib, show promising clinical outcomes, relapsed MCL often acquires drug resistance. Therefore, alternative approaches for refractory and relapsed MCL are needed. Here, we examined whether a novel inhibitor of enhancer of zeste homologs 1 and 2 (EZH1/2), OR-S1 (a close analog of the clinical-stage compound valemetostat), had an antitumor effect on MCL cells. In an ibrutinib-resistant MCL patient-derived xenograft (PDX) mouse model, OR-S1 treatment by oral administration significantly inhibited MCL tumor growth, whereas ibrutinib did not. In vitro growth assays showed that compared with an established EZH2-specific inhibitor GSK126, OR-S1 had a marked antitumor effect on MCL cell lines. Furthermore, comprehensive gene expression analysis was performed using OR-S1-sensitive or insensitive MCL cell lines and showed that OR-S1 treatment modulated B-cell activation, differentiation, and cell cycle. In addition, we identified Cyclin Dependent Kinase Inhibitor 1C (CDKN1C, also known as p57, KIP2), which contributes to cell cycle arrest, as a direct target of EZH1/2 and showed that its expression influenced MCL cell proliferation. These results suggest that EZH1/2 may be a potential novel target for the treatment of aggressive ibrutinib-resistant MCL via CDKN1C-mediated cell cycle arrest.

Outcomes of hematopoietic cell transplantation for transformed follicular lymphoma.

This study characterized the outcomes of patients who underwent hematopoietic cell transplantation (HCT) for transformed follicular lymphoma (tFL), and clarified the association of low-dose anti-thymocyte globulin use with outcomes after allogeneic HCT. The retrospective study cohort included 74 consecutive patients who underwent autologous (n = 23) or allogeneic (n = 51) HCT at our center from 2000 to 2017. Compared with the allogeneic HCT group, the autologous HCT group underwent fewer systemic regimens before HCT (median 2 vs. 5, p < 0.001) and were more likely to have chemosensitive disease at HCT (100% vs. 82%, p = 0.05), while age, sex and HCT-specific comorbidity index were similar between the two groups. With a median follow-up of 5.8 years among survivors, the 5-year probability of progression-free survival was 64% after autologous HCT and 55% after allogeneic HCT (p = 0.21). The 5-year cumulative incidence of non-relapse mortality was 0% after autologous HCT and 9.5% after allogeneic HCT (p = 0.062). The 5-year cumulative incidence of disease progression was similar between autologous and allogeneic HCT (36% vs. 36%, respectively, p = 0.88). In the allogeneic HCT group, the use of low-dose anti-thymocyte globulin was associated with a lower incidence of severe acute GVHD but not with an increased risk of mortality or disease progression. More than half of patients with early phase chemosensitive tFL and approximately half of those with advanced-phase tFL achieved long-term progression-free survival with autologous and allogeneic HCT, respectively. Disease progression was the major cause of treatment failure after both types of HCT. Further strategies are needed to reduce the risk of disease progression.

Clinicopathological factors and tumor microenvironment markers predicting watch-and-wait discontinuation in 82 patients with follicular lymphoma.

OBJECTIVES: In this study, we aimed to determine the clinicopathological factors influencing the treatment-free period in patients with follicular lymphoma (FL) using a watch-and-wait (WW) strategy. METHODS: We retrospectively assessed histopathological parameters of 82 patients with FL. RESULTS: The median time from diagnosis to WW discontinuation was 62 months (range, 3-138), and median follow-up was 86 months (range, 3-183). Intermediate or high-risk Follicular Lymphoma International Prognostic Index score (P = .012), non-duodenal-type (P = .011), higher numbers of interfollicular CD4+ (P = .038) and intrafollicular FOXP3+ cells (P = .024) in the tumor microenvironment, and Ki-67 index ≥10% (P = .031) were significant adverse factors for WW discontinuation in univariate analyses. CONCLUSION: Patients with adverse factors for WW discontinuation should be carefully observed during follow-up.

The role of local radiotherapy following rituximab-containing chemotherapy in patients with transformed indolent B-cell lymphoma.

OBJECTIVES: This study aimed to evaluate the outcomes of local radiotherapy (LRT) in patients with histologic transformation (HT) following rituximab-containing chemotherapy. METHODS: We retrospectively analysed 92 patients with biopsy-confirmed HT undergoing rituximab-containing chemotherapy at our institution between 2003 and 2015. RESULTS: Of the 36 patients with limited-stage disease at diagnosis of HT, 29 (78%) received LRT. The estimated 5-year progression-free survival (PFS) rate was significantly better in patients who underwent LRT than in those who did not (93% and 42%, respectively; P < 0.05). Multivariate analyses employing age, sex, performance status, LRT and treatment response demonstrated that LRT was an independent prognostic factor for PFS (hazard ratio [HR]: 11.8; 95% confidence interval [CI]: 1.28-108.1; P < 0.05). Of the 32 patients who underwent LRT for HT lesion treatment, 31 (97%) did not show disease progression within radiation fields; among them, 27 patients (84%) survived without disease progression during the follow-up period. One patient developed hypothyroidism due to LRT; the others had no acute or late-onset complications of LRT. CONCLUSIONS: Our data support the recommendation of LRT for HT lesion treatment following rituximab-containing chemotherapy in select patients with localised HT, as a rational treatment approach with potentially limited toxicity.

Use of Core-Needle Biopsy for the Diagnosis of Malignant Lymphomas in Clinical Practice.

INTRODUCTION: Excisional biopsy (EB) is considered the gold standard for lymphoma diagnosis. Although recent advances in interventional radiology enable sampling with core-needle biopsy (CNB), only few studies evaluated the utility of CNB compared to that of EB. METHODS: We analyzed patients with lymphoma who had a diagnostic biopsy at the National Cancer Center Hospital during 2002-2017. We investigated the clinical and pathological characteristics of CNB in 2017. RESULTS: The proportion of CNB utility in total biopsy procedures had increased from 11 to 48% during the 15 years. In 2017, CNB was opted more frequently than EB for a biopsy of superficial, abdominal, or anterior mediastinal lesions. Only one out of 72 patients who had CNB required re-biopsy with EB because of insufficiency. The incidence of complications was comparable between CNB and EB: 2 (4%) cases of minor bleeding with CNB and 1 (8%) case of minor bleeding with EB. The median time from the first visit to biopsy was significantly shorter with CNB (5.5 days) than with EB (15 days). CONCLUSION: There is an increasing trend in the utility of CNB. CNB is a less invasive method with shorter time to biopsy and can be considered an alternative to EB.

A phase II Japanese trial of fludarabine, cyclophosphamide and rituximab for previously untreated chronic lymphocytic leukemia.

OBJECTIVE: Fludarabine, cyclophosphamide and rituximab (FCR) is the standard regimen for fit patients with untreated CD20-positive chronic lymphocytic leukemia (CLL). However, this combination is unavailable in Japan because rituximab is not approved for CLL. We investigated the efficacy and safety of FCR in this single-arm, multicenter study designed as a bridging study to the CLL8 study by the German CLL Study Group. METHODS: The study enrolled previously untreated patients with CLL of Binet stage B or C with active disease. Patients with a Cumulative Illness Rating Scale score of ≤6 and creatinine clearance of ≥70 ml/min were eligible. Patients received 6 cycles of FCR every 28 days and were followed for up to 1 year. RESULTS: Seven patients were enrolled. The best overall response rate according to the 1996 NCI-WG Guidelines, the primary endpoint of the study, was 71.4% (95% confidence interval, 29.0-96.3%), with one patient achieving complete response. No deaths or progression occurred during follow-up. The main adverse event was hematotoxicity. CD4-positive T-cell count decreased in all patients; most patients showed no reduction in serum immunoglobulin G. CONCLUSION: Although the number of patients was limited, FCR appears to be effective with manageable toxicity for treatment-naïve fit Japanese patients with CD20-positive CLL. CLINICAL TRIAL NUMBER: JapicCTI-132285.

Usefulness of hematopoietic progenitor cell monitoring to predict autologous peripheral blood stem cell harvest timing: A single-center retrospective study.

INTRODUCTION: In autologous peripheral blood stem cell harvest (APBSCH), CD34-positive cells have been measured to assess the numbers of hematopoietic stem cells, but measurement requires specialized equipment. Recently, there was a report that peripheral blood hematopoietic progenitor cells (HPCs) are useful indicators of the presence of hematopoietic stem cells. We examined the usefulness of HPC monitoring to predict APBSCH timing. METHODS: We retrospectively analyzed the relationship between HPC and collected CD34-positive cells in 84 consecutive patients who underwent APBSCH. RESULTS: According to the receiver operating characteristics curve for the collection of ≥2 × 106 CD34-positive cells/kg, the HPC cut-off value on the day before collection was 21/µL, while that on the day of collection was 41/µL. No significant factors were found in the univariate analysis except for the HPC count on the day before collection (p < 0.001) and the day of collection (p < 0.001). According to the multivariate analysis, the HPC count on the day before collection (p < 0.001) and the day of collection (p < 0.001) were also factors that strongly influenced the quantity of CD34-positive cells collected. CONCLUSION: Our results suggest that the HPC count on not only the day of collection but also the day before collection is a good indicator for appropriate APBSCH timing.

Diagnostic utility and prognostic significance of the Ki-67 labeling index in diffuse large B-cell lymphoma transformed from follicular lymphoma: a study of 76 patients.

The diagnosis of histological transformation of follicular lymphoma can be challenging and ambiguous. We investigated the distribution of the Ki-67 labeling index of histological transformation of follicular lymphoma and determined its cutoff value to predict poor outcomes. The diagnostic criteria for histological transformation were a diffuse pattern of proliferation and a proportion of large lymphoma cells ≥20%. Of the 1121 patients with follicular lymphoma, 171 (15%) showed histological transformation to diffuse large B-cell lymphoma. Of these, 76 patients, whose biopsies were obtained from the sites with the highest maximum standardized uptake values, according to the positron emission tomography findings, were included. The Ki-67 index ranged from 16.8% to 98.4% (median, 60.6%). In patients with histological transformation, the most significant differences were found in progression-free survival (p = 0.087, 58% vs. 87% at 2 years) and overall survival (p = 0.024, 53% vs. 85% at 5 years) when a 70% cutoff was used. Additionally, overall survival was significantly shorter in patients with histological transformation with maximum standardized uptake values of ≥20 (p < 0.0001) and absence of a follicular lymphoma component (p = 0.004). A Ki-67 index of ≥70% was a significant adverse factor for overall survival in patients with histological transformation of follicular lymphoma and may predict poor outcomes.

Immunohistochemical CD20-negative change in B-cell non-Hodgkin lymphomas after rituximab-containing therapy.

CD20- change after rituximab-containing therapy is considered one of the main reasons of rituximab resistance of B-cell non-Hodgkin lymphomas (B-NHLs). However, the clinicopathological characteristics of B-NHL with CD20- change are not entirely understood. In this study, 252 B-NHL patients who were CD20+ at initial diagnosis, whose diseases relapsed or were refractory after rituximab-containing therapy, and who were re-biopsied between 2000 and 2018, were included. The median number of rituximab administration was 11 (range, 1-48). Completely negative (cCD20-) and partially negative (pCD20-) change of CD20 was observed in 49 (20%) and 16 (6%) cases, respectively. Among cCD20- and pCD20- cases, 74% and 62% of the cases changed to CD20- at the second relapse or later, respectively. Overall survival was significantly shorter in cCD20- follicular lymphoma (FL) cases than in CD20+ FL cases. Seven histopathological patterns, such as CD20- change without histological change, histological transformation (HT) to CD20- diffuse large B-cell lymphoma, and proliferation of plasmablastic/plasmacytoid tumor cells, were associated with CD20- change. HT occurred more frequently in FLs with CD20- change than in FLs continuously expressing CD20 (P < 0.0001), regardless of the timing of HT. Nine out of 25 cases (36%) showed regain or heterogeneous regain of CD20 expression. In conclusion, 20% and 6% of the 252 B-NHL cases show cCD20- and pCD20- changes with 7 histological patterns after rituximab-containing therapy. Because changes in morphology and CD20 expression after rituximab-containing therapy vary, and recovery of CD20 expression is not rare, careful follow-up and re-biopsy in B-NHL patients are recommended.

Phase I study of tirabrutinib (ONO-4059/GS-4059) in patients with relapsed or refractory B-cell malignancies in Japan.

We evaluated the safety, efficacy, pharmacokinetics, pharmacodynamics and predictive biomarkers of tirabrutinib, a second-generation, enhanced-selectivity Bruton's tyrosine kinase inhibitor in Japanese patients with relapsed/refractory B-cell non-Hodgkin lymphoma (B-cell NHL) and chronic lymphocytic leukemia (CLL). This was an open-label, multicenter, phase I study. Seventeen patients (male N = 8) with a median age of 70 years were enrolled in 4 dose cohorts (160 mg once daily [N = 3], 320 mg once daily [N = 3], 480 mg once daily [N = 4] and 300 mg twice daily [N = 7]); 4 patients had continued tirabrutinib administration as of 4 January 2018. The maximum tolerated dose was not reached. Pneumonitis (N = 1) was the dose-limiting toxicity for 300 mg twice daily. Common adverse events (AEs) were rash (35.3%) and vomiting (29.4%). Eight patients (47.1%) developed grade ≥3 AEs: neutropenia (23.5%), anemia (11.8%) and leukopenia (11.8%) were frequent. The overall response rate (≥PR) was 76.5% (13/17 patients), including 4 DLBCL patients with no CD79A/B or MYD88 mutations, and 1 CLL patient with a TP53 mutation, providing promising data for future developments. Of 16 patients with measurable lesions during the screening period, 12 showed ≥50% reductions in tumor diameter. In many patients, the tumor size decreased soon after beginning treatment. The maximum serum concentration for tirabrutinib was 611, 1220, 1280 and 886 ng/mL on Day 1 and 484, 971 1940, and 961 ng/mL on Day 28 for Cohorts 1-4, respectively. Tirabrutinib pharmacokinetics were linear, with little accumulation following multiple doses. Tirabrutinib was well tolerated and showed promising efficacy for B-cell NHL/CLL.

Mucosa-associated lymphoid tissue lymphoma with t(11;18)(q21;q21) translocation: long-term follow-up results.

Translocation (11;18)(q21;q21) is found in mucosa-associated lymphoid tissue (MALT) lymphoma, resulting in API2/MALT1 gene fusion. It is known that t(11;18)-positive MALT lymphoma shows a tendency to disseminate and be resistant to Helicobacter pylori eradication by antibiotics. However, the prognostic features including recurrence and histological transformation (HT) remain unknown. We conducted a single-institute retrospective analysis of 464 patients with newly diagnosed MALT lymphoma, evaluating the impact of t(11;18) on clinical outcomes. One hundred and six patients were screened for the translocation by fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction. Of these patients, 26 patients (25%) were diagnosed as MALT lymphoma with t(11;18). The patients had a significantly shortened progression-free survival (PFS at 10 years; 26% v 57%; P = 0.004) compared to those without t(11;18). However, this did not translate into overall survival or incidence of HT. We confirmed previous reports stating that t(11;18)-positive MALT lymphoma showed disseminated disease and refractoriness to H. pylori eradication therapy. Patients with t(11;18) had more frequent monoclonal gammopathy, especially of IgM subtype (31% v 8%; P = 0.008), some of which developed class switch. These findings characterize the features of t(11;18)-positive MALT lymphoma, suggesting that it comprises a distinct clinical entity of MALT lymphoma.

EBV-encoded RNA1-positive cells in the bone marrow specimens of patients with EBV-negative lymphomas and sarcomas.

Epstein-Barr virus (EBV) infection is associated with pathogenesis of various cancers, including extranodal natural killer/T-cell lymphoma, nasal type (ENKL). ENKL tumor cells are positive for EBV-encoded RNA1 (EBER1), which is the most useful marker to identify ENKL tumor cells in histopathology. Currently, EBER1 in situ hybridization (ISH) is recommended to evaluate bone marrow (BM) involvement of ENKL. However, the actual burden of EBER1-positive cells in normal BM specimens remains unclear. In the present study, we performed EBER1 ISH on 111 BM specimens, which were obtained during an initial staging procedure in patients with EBV-negative cancers and were also negative for BM involvement. One or more EBER1-positive cells per whole specimen were observed in 38 specimens (34%). The number of EBER1-positive cells was distributed as follows: single positive cell, n = 17; two positive cells, n = 13; three positive cells, n = 3; and four positive cells, n = 5. These findings suggest that four or fewer EBER1-positive cells can be observed in BM specimens of patients with non-EBV-related cancers. The clinical implications of a small number of EBER1-positive cells in BM specimens of patients with ENKL should be evaluated in further studies.

Partial deletion of the ALK gene in ALK-positive anaplastic large cell lymphoma.

Anaplastic lymphoma kinase (ALK) protein is an orphan receptor tyrosine kinase that is constitutively activated by aberrant translocations of the ALK gene in anaplastic large cell lymphoma, ALK-positive and several other cancers. Additionally, aberrant mutation and amplification of the ALK gene, resulting in ALK kinase activation, were detected mainly in neuroblastoma. Recently, truncated ALK protein was also reported in neuroblastoma. Here, we describe a novel truncated form of the ALK transcript with in-frame skipping through exons 2 to 17 (ALKΔ2-17) in anaplastic large cell lymphoma, ALK-positive. The ALKΔ2-17 showed ligand-independent deregulated phosphorylation that initiated strong STAT3 signalling in NIH3T3 cells. The ALKΔ2-17-transduced NIH3T3 cells showed oncogenic potential in a colony formation assay. Our data indicate that the aberrant deletion of the ALK gene might be oncogenic, providing a novel insight into the oncogenic role of the ALK pathway.

Expression pattern of PD-L1 and PD-L2 in classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, and gray zone lymphoma.

OBJECTIVES: We aimed at investigating the relationship between classical Hodgkin lymphoma (cHL), primary mediastinal large B-cell lymphoma (PMBL), and gray zone lymphoma (GZL) with intermediate characteristics between cHL and PMBL, from the perspective of the aberration in programed cell death 1 and the programed death ligands (PDLs) network. METHODS: We explored the expression levels of PDLs and chromosomal anomalies in 67 cases: 34 cases with cHL, 20 with PMBL, and 13 with GZL, using immunohistochemical analyses and Fluorescence In Situ Hybridization (FISH). RESULTS: Twenty-one cHL (62%), 3 PMBL (15%), and 6 GZL (46%) cases showed staining to PD-L1 antibodies in more than 70% of tumor cells. Two cHL (6%), 10 PMBL (50%), and 3 GZL (23%) cases were not stained by PD-L1 antibodies. Patients over 40 years old manifest more frequent expression of PD-L1 in cHL. Proportion of tumors stained by PD-L2 antibody was increased in PMBL. FISH analyses with a PD-L1/PD-L2 probe detected 5 amplification, 1 gain, and 7 polysomy cases in cHL, 1 amplification and 1 polysomy case in GZL, and amplification in 1 PMBL case. CONCLUSION: We identified increased staining of PD-L1 in cHL and that of PD-L2 in PMBL. GZL had a pattern similar to that of cHL.

Prognosis of patients with peripheral T cell lymphoma who achieve complete response after CHOP/CHOP-like chemotherapy without autologous stem cell transplantation as an initial treatment.

Cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)/CHOP-like chemotherapy has been mostly applied to patients with untreated peripheral T cell lymphoma (PTCL). Because the long-term outcome of patients with PTCL, especially those achieving complete response (CR), has not been fully elucidated, we retrospectively analyzed 78 consecutive patients initially treated with CHOP/CHOP-like chemotherapy, without high-dose chemotherapy followed by autologous stem cell transplantation (HDC/auto-SCT). Median overall and progression-free survivals in all 78 patients were 44 and 17 months, respectively, with a median follow-up of 62 months. In the 53 patients achieving CR, the median relapse-free survival (RFS) was 21 months, and 2-, 3-, and 5-year RFSs were 46, 45, and 36%, respectively. Although our results showed an unfavorable outcome for PTCL as a whole, those who achieved CR following CHOP/CHOP-like chemotherapy did not always have a poor outcome without the consolidation of HDC/auto-SCT; in particular, 45% of the 65 years or younger patients were alive without disease at 5 years.

Clinicopathological features of histological transformation from extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue to diffuse large B-cell lymphoma: an analysis of 467 patients.

This study analysed incidence, patient outcome, immunophenotype and prognostic factors of histological transformation (HT) from extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) to diffuse large B-cell lymphoma (DLBCL) in 467 patients (median age, 61 years). The primary sites of MALT lymphoma were the stomach (43%), ocular adnexa (25%), lung (8%), systemic (8%) and other tissues (16%). HT occurred in 8% of MALT lymphomas. Risk of HT by 15 years was 5%: 4% in limited-stage diseases (n = 385) and 16% in advanced-stage diseases (n = 56) (P = 0·02). The median time to HT was 48 months (range, 4-139). Five-year progression-free survival (PFS) and overall survival (OS) rates after HT were 80% and 94%, respectively. Immunohistochemical results of DLBCL were as follows: germinal centre B-cell (GCB)/non-GCB, 37%/63%; CD10, 9%; BCL6, 59%; MUM1, 38%; MYC, 42%; BCL2, 35%; Ki67 ≥ 90%, 23%; and CD5, 3%. The majority (75%, 9/12) of GCB-type DLBCLs exhibited CD10(-) , BCL6(+) and MUM1(-) immunophenotypes; the remainder had CD10(+) immunophenotypes. Multivariate analysis revealed that only advanced stage at HT was a significant adverse factor for PFS (P = 0·037). Thus, overall risk of HT was low and prognosis after HT was favourable; however, in advanced-stage cases, risk of HT was relatively high and prognosis was unfavourable.