Abstract: 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.

Abstract: Although histologic analysis is the gold standard for diagnosing follicular lymphoma (FL) transformation, many patients are diagnosed with transformation by clinical factors as biopsy specimens often cannot be obtained. Despite the frequency of clinical diagnosis, no clinical assessment tool has yet been established for FL transformation in the rituximab era. We derived and validated a transformation scoring system (TSS) based on retrospective analyses of 126 patients with biopsy‐proven FL and histologic transformation (HT) at two hospitals of the National Cancer Center of Japan. In the derivation set (76 patients), the detailed analyses of the clinical characteristics at disease progression showed that lactate dehydrogenase (LDH) elevation, focal lymph nodal (LN) enlargement, hemoglobin 〈 12 g/dl, and poor performance status (PS) (2‐4) were associated with HT. The weights of these variables were decided based on the regression coefficients. Next, we constructed a TSS encompassing the above four factors: LDH, ( 〉 upper limit of normal [ULN], ≤ULN ×2) (1 point), (≥ULN ×2) (2 points); focal LN enlargement, (≥3 cm, 〈 7 cm) (1 point), (≥7 cm) (2 points); hemoglobin 〈 12 g/dl (1 point); poor PS (2 points). We identified a high positive predictive value (PPV) (96.4%) and negative predictive value (NPV) (85.4%) for diagnosing HT when a cutoff score of 2 was selected for our TSS. In an external validation set (50 patients), the probability of HT was high with scores ≥2 (PPV, 93.3%; NPV, 82.9%). We developed a TSS that offers a simple, yet, valuable tool, for diagnosing HT, especially in patients who cannot undergo biopsy.

Abstract: Introduction: In limited-stage diffuse large B-cell lymphoma (DLBCL), a continued risk of relapse has been reported (Stephens et al. J Clin Oncol 2016). Another report highlighted that initial limited-stage DLBCL, a favorable International Prognostic Index and extranodal involvement seemed to be risk factors for late relapse (LR; Larouche et al. J Clin Oncol 2010). However, even if a subgroup of patients (pts) with LR shows distinct clinical characteristics, the underlying biology is largely unknown. Methods: Nineteen consecutive pts who developed LR were identified among 337 pts with de novo DLBCL of Ann Arbor stage I/II who were treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone), with/without rituximab, between 1997 and 2012. LR was defined as the first relapse of B-cell lymphoma (BCL; including indolent BCL) occurring more than 5 years after a primary diagnosis. The 19 pts underwent clinical, pathological (cell of origin according to the Hans algorithm) and genetic analyses. Genomic DNA (gDNA) was extracted from formalin-fixed, paraffin-embedded sections of tumor specimens at primary diagnosis and relapse, and from bone marrow (BM) specimens without tumor invasion as controls. Genomic DNA samples from paired primary and relapsed tumors were analyzed using BIOMED-2 multiplex PCR for immunoglobulin heavy chain (IGH) rearrangements (Invivoscribe Technologies, San Diego, CA, USA) to determine whether the paired tumors shared the same clonal IGH rearrangements. Target sequencing of 2709 regions across 69 lymphoma-related genes was performed on gDNA samples. Mutational calls were made in comparisons with individual control BM gDNA samples according to the criteria outlined in Table 1. All functional mutations detected in paired tumors per pt were compared, and shared and non-shared mutations were identified. Results: Baseline characteristics of the 19 pts were as follows: median age of 60 years (range, 32-77); 13 (68%) had stage I disease, and 11 (58%) had extranodal disease. At primary diagnosis, 14 of 19 pts (74%) had a non-germinal center B-cell-like (non-GCB) type DLBCL. As an initial treatment, CHOP therapy (median 4 cycles; range, 3-8), with (n=17) or without (n=2) radiation therapy, was performed in all 19 pts. Seven pts were treated with CHOP and rituximab. The median duration from initial diagnosis to LR was 8 years (range, 5-18). At LR, the median age was 71 years (range, 45-84). One pt relapsed as a composite of DLBCL and indolent BCL, and two pts relapsed as indolent BCL. Seven of the 19 pts were excluded from gene analysis because their paired gDNAs were of poor quality. The results of target sequencing combined with clinicopathological information and the results of IGH-PCR analysis are described in Table 2. Shared mutations between individual pairs of primary and relapsed tumors were detected in nine of the 12 pts analyzed. The most frequent shared mutation was a CD79B missense mutation of a single base substitution in positions 196 (n=5) or 199 (n=2). The second most frequent mutation was a MYD88 (L265P) missense mutation (n=5). Co-mutation of CD79B and MYD88 was found in four pts, who were considered to have a MCD (MyD88,CD79b) type DLBCL (Schmitz et al. N Engl J Med 2018). All eight pts with a CD79B and/or MYD88 mutation had a non-GCB type DLBCL. The same clonal IGH rearrangements between paired tumors were found in six of the eight pts. Seven of the eight pts presented with primarily extranodal disease originating from the testis (n=3), nasal/paranasal cavity (n=2) or gingiva (n=2). One pt (#9 in Table 2) with a GCB type DLBCL had shared mutations in MLL2, CREBBP, MEF2B and PIM1. However, different clonal IGH rearrangements were detected between paired tumors, implying these mutations may be the basis for lymphomagenesis; an on-going IGH rearrangement may occur. In the other three pts (#10-12), shared mutations were not detected. Mutations in TP53 were not detected in any pts. We did not identify any specific mutations considered to be associated with LR. Conclusions: Common characteristics shared in a subgroup of pts with limited-stage DLBCL who developed LR were as follows: non-GCB type, CD79B and/or MYD88 mutations, and extranodal disease at primary manifestation. The mechanisms of LR from the viewpoint of gene alterations were considered heterogeneous. Disclosures Maruyama: Asahi Kasei Pharma: Honoraria; Takeda: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Dai-ichi-Sankyo: Honoraria; Dai-Nippon-Sumitomo: Honoraria; MSD: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Fujifilm: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; AstraZeneca: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Abbvie: Research Funding; Astellas Pharma: Research Funding; Amgen Astellas BioPharma: Research Funding; Otsuka: Research Funding; Novartis: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Pfizer: Research Funding; Solasia Pharma: Research Funding; Celgene: Honoraria, Research Funding; Biomedis International: Honoraria, Research Funding; Mundipharma International: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Izutsu:Amgen: Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria; Bayer: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; MSD: Honoraria; HUYA Bioscience International: Research Funding; Celgene: Consultancy, Research Funding; Celltrion: Research Funding; Zenyaku: Research Funding; Sanofi: Research Funding; Gilead Sciences: Honoraria; Eisai: Honoraria, Research Funding; Novartis: Honoraria; Ono: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Nihon Medi-Physics: Honoraria; Symbio: Research Funding; Solasia: Research Funding; Mundhi: Honoraria; Otsuka: Honoraria; Bristol- Myers Squibb: Honoraria; Janssen: Honoraria, Research Funding; Astellas: Honoraria, Research Funding; Meiji Seika: Honoraria; Shionogi: Honoraria; Asahi Kasei: Honoraria. Tobinai:Takeda: Honoraria, Research Funding; SERVIER: Research Funding; Abbvie: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Chugai Pharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding. Kobayashi:Pfizer: Research Funding; Ohtuka: Research Funding; Astellas: Research Funding.

Abstract: 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.

Abstract: Approximately 15% of patients with diffuse large B‐cell lymphoma (DLBCL) experience refractory or early relapsed disease after initial rituximab‐containing chemoimmunotherapy is regarded as a primary refractory disease. Although the standard treatment for relapsed DLBCL is high‐dose chemotherapy and autologous stem cell transplantation (HDC‐ASCT), the efficacy of this approach for primary refractory DLBCL is not well understood. We aimed to investigate the clinicopathological characteristics and outcomes of patients with primary refractory DLBCL. Methods Sixty‐nine consecutive patients with primary refractory DLBCL who were treated at our institution were categorized as partial responders (partial response to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone [R‐CHOP] or relapse within 6 months of R‐CHOP) ( n  = 41) or primary progressors (no response to R‐CHOP) ( n  = 28). Survival curves were constructed using the Kaplan–Meier method and compared using the log‐rank test. Results At initial diagnosis, 70% of patients had Ann Arbor stage III/IV disease, 56% had non‐germinal center B‐cell‐like type DLBCL, and 42% had double‐expressor lymphoma (MYC and BCL2 expression). The 3‐year overall survival rate was significantly poorer in the primary progressors group than in the partial responders’ group (15% vs. 48%, p   〈  0.001). Four of 17 patients treated with HDC‐ASCT were primary progressors; only one patient survived without relapse. Although double‐expressor lymphoma status did not significantly impact overall survival among all patients ( p  = 0.794), it was identified as an independent poor prognostic factor in HDC‐ASCT‐treated patients ( p  = 0.002). Conclusions We identified a subgroup of patients with primary refractory DLBCL who may not benefit from current treatment strategies. Further treatment development is needed to improve the outcomes of these patients.

Abstract: 〈 b 〉 〈 i 〉 Introduction: 〈 /i 〉 〈 /b 〉 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. 〈 b 〉 〈 i 〉 Methods: 〈 /i 〉 〈 /b 〉 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. 〈 b 〉 〈 i 〉 Results: 〈 /i 〉 〈 /b 〉 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). 〈 b 〉 〈 i 〉 Conclusion: 〈 /i 〉 〈 /b 〉 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.

Abstract: Introduction Although the Japanese multicenter phase II trial in localized primary gastric diffuse large B-cell lymphoma (PG-DLBCL), which evaluated three cycles of CHOP followed by radiotherapy (RT), showed good prognosis (Cancer Sci 2005; 96: 349), reports about outcomes and prognostic factors of localized PG-DLBCL patients in the rituximab era are limited. Recently, it has been reported that the concurrent expression of MYC and BCL2 predicts unfavorable outcome in DLBCL patients treated with R-CHOP (J Clin Oncol 2012; 30: 3460). However, the impact of the concurrent expression of MYC and BCL2 on outcomes of localized PG-DLBCL patients has never been reported. Patients and Methods We retrospectively analyzed 52 consecutive patients diagnosed as having localized (stage I or II according to the Lugano Staging System for Gastrointestinal Lymphomas) PG-DLBCL who were initially treated at our institution between 2003 and 2013. Positivity of MYC in immunohistochemistry was defined as labeling of tumor cells of more than 40% and positivity of BCL2 was defined as more than 70%. The lymphoma cells were assigned a GCB or non-GCB phenotype using the Hans algorithm for determining the cell-of-origin (COO) subtyping. Results Twenty-four (46%) patients were male and 28 (54%) female, with a median age of 62 years (range: 29-85). Thirty (58%) patients presented with stage I disease, 15 (29%) with stage II1, two (4%) with stage II2 and five (9%) patients with stage IIE. Most patients (47 patients; 90%) had low or low-intermediate risk based on the International Prognostic Index. Fifty (96%) patients received R-CHOP with or without RT, and one each received CHOP plus RT, and total gastrectomy followed by rituximab. The median number of CHOP cycles was three (range: 2-8). The majority (43 patients; 83%) of patients were treated with R-CHOP followed by RT. COO subtype could be determined in 48 of the 52 patients (63% GCB and 37% non-GCB). Both MYC and BCL2 expression could be assessed in 47 of the 52 patients, and the concurrent expression of MYC and BCL2 was confirmed in seven (15%) patients. In this analysis, no patients showed positivity for EBER-1 in situ hybridization, which was reported as an adverse prognostic factor of localized PG-DLBCL in the pre-rituximab era. Median follow-up duration was 76 months (range: 4-127 months). Fifty (96%) patients achieved complete responses, and the remaining two without concurrent expression of MYC and BCL2 had primary refractory disease. The estimated 5-year overall and progression-free survival rates of all 52 patients were 90% (95% CI, 75-96%) and 89% (95% CI, 75-95%), respectively (Fig. 1). The estimated 5-year overall survival rates of GCB phenotype and non-GCB phenotype cases were 86% (95% CI, 63-96%) and 93% (95% CI, 59-99%), respectively, with no statistically significant difference (p=0.96). The estimated 5-year overall survival rates of the patients with and without concurrent expression of MYC and BCL2 were 100% and 88% (95% CI, 72-96%), respectively (Fig. 2). There was no significant difference between the two cohorts (p=0.74). Conclusions The results of our analysis showed good prognosis, and revealed that COO subtype and concurrent expression of MYC and BCL2 did not influence the outcome in patients with localized PG-DLBCL treated with rituximab-containing chemotherapy with or without RT. Further investigations, especially a prospective cohort study, are needed to confirm our results. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Maruyama: Eisai Co., Ltd: Honoraria. Kobayashi:Otsuka Pharmaceutical Co., Ltd.: Research Funding; ARIAD Pharmaceuticals, Inc.: Research Funding; Boehringer Ingelheim GmbH: Research Funding. Tobinai:Zenyaku Kogyo: Research Funding; Chugai Pharmaceutical: Research Funding.

Abstract: 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.