Chinese Diffuse Large B-cell Lymphoma Patients Research Articles

Circulating tumor DNA mutation profile is associated with the prognosis and treatment response of Chinese patients with newly diagnosed diffuse large B-cell lymphoma

Characterization of gene mutation profiles can provide new treatment options for patients with diffuse large B-cell lymphoma (DLBCL). However, this method is challenged by the limited source of tissue specimens, especially those of DLBCL patients at advanced stages. Therefore, in the current study, we aimed to describe the gene mutation landscape of DLBCL using circulating tumor DNA (ctDNA) samples obtained from patients' blood samples, as well as to explore the relationship between ctDNA mutations and the prognosis and treatment response of patients with newly diagnosed DLBCL. A total of 169 newly diagnosed Chinese DLBCL patients were included in this study, among which 85 patients were divided into a training set and 84 were assigned into a validation set. The mutation profile of a 59-gene panel was analyzed by targeted next generation sequencing (NGS) of the patients' ctDNA samples. Differences in clinical factors between patients with and without ctDNA mutations were analyzed. In addition, we also explored gene mutation frequencies between GCB and non-GCB subtypes, and the relationship between gene mutation status, clinical factors, mean VAF (variant allele frequencies) and the patients' overall survival (OS) and progression-free survival (PFS). ctDNA mutations were detected in 64 (75.3%) patients of the training set and 67 (79.8%) patients of the validation set. The most commonly mutated genes in both sets were PCLO, PIM1, MYD88, TP53, KMT2D, CD79B, HIST1H1E and LRP1B, with mutation frequencies of >10%. Patients with detectable ctDNA mutations trended to present advanced Ann Arbor stages (III-IV), elevated LDH (lactate dehydrogenase) levels, shorter OS and PFS, and a lower complete response (CR) rate to the R-CHOP regimen compared with DLBCL patients without ctDNA mutations. In addition, mean VAF (≥4.94%) and PCLO mutations were associated with poor OS and PFS. We investigated the ctDNA mutation landscape in Chinese patients with newly diagnosed DLBCL and found that ctDNA could reflect tumor burden and patients with detectable ctDNA mutations trended to have shorter OS and PFS and a lower CR rate.

Clinical characteristics and treatment outcomes of Chinese diffuse large B-cell lymphoma patients in the era of rituximab (2005–2018)

BackgroundRituximab combined with cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone (R–CHOP) regimen has improved the survival of diffuse large B-cell lymphoma (DLBCL) patients worldwide, compared with CHOP alone. Several limitations were seen in previous studies of Chinese DLBCL patients treated with R–CHOP or R-CHOP-like regimens. This study aimed to investigate the clinical characteristics and treatment outcomes of Chinese DLBCL patients treated with the standard first-line treatment. MethodsClinical data were collected from DLBCL patients who received frontline R–CHOP or R-CHOP–like regimens at the Cancer Hospital Chinese Academy of Medical Sciences & Peking Union Medical College (CHCAMS) between January 1, 2005, and December 31, 2018. The treatment outcomes were compared with those of patients diagnosed with DLBCL between 2004 and 2017 and who received immunochemotherapy from the United States Surveillance, Epidemiology, and End Results (SEER) database. Survival rates were estimated using the Kaplan–Meier method and compared using the log-rank test. Multivariate analysis of progression-free survival (PFS) and overall survival (OS) was performed using Cox proportional hazard regression. ResultsOverall, 1084 patients from the CHCAMS and 4013 patients from the SEER database were included in the study. As of April 30, 2022, the median follow-up period for the CHCAMS group was 87.3 (range: 0.5–195.4) months. For the CHCAMS group, the 5-year PFS and OS rates were 61.7% (95% confidence interval [CI]: 58.8–64.7%) and 70.6% (95% CI: 67.8–73.4%), respectively. For the SEER group, the 5-year OS rate was 66.5% (95% CI: 65.0–68.0%), which was inferior to that of the CHCAMS group (P ​< ​0.001). After adjusting for clinical factors and treatment, no significant difference was observed in the OS between the CHCAMS and SEER groups (P ​= ​0.867). In the CHCAMS group, multivariate analysis showed that an Eastern Cooperative Oncology Group performance status score ≥2, presence of B symptoms, Ann Arbor stage III–IV, elevated serum β2-microglobulin levels, and bulky mass were independent adverse prognostic factors affecting PFS and OS (P ​< ​0.05). Additionally, patients aged over 60 years, elevated lactate dehydrogenase levels, and more than two extranodal sites were independent adverse prognostic factors for OS (P ​< ​0.05). Local radiotherapy was significantly associated with better PFS (P ​< ​0.001) and OS (P ​= ​0.001). ConclusionAfter adjusting for clinical and treatment-related factors, no significant difference was observed in the 5-year OS rate between Chinese DLBCL patients treated with standard first-line treatment and those from the SEER database.

624MO Retrospective analysis of clinical value of ctDNA in newly diagnosed diffuse large B cell lymphoma

Diffuse Large B Cell Lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma with high incidence, strong clinical and genetic heterogeneity. Current clinical characteristics are insufficient for the prognostic stratification of DLBCL. In recently, circulating tumor DNA (ctDNA) emerging as a biomarker for DLBCL prognostic stratification. However, whether it could use ctDNA as a biomarker to detect mutated genes in samples from Chinese DLBCL patients is uncertain.

Tumor mutation burden estimated by a 69-gene-panel is associated with overall survival in patients with diffuse large B-cell lymphoma

BackgroundTumor mutation burden (TMB) as estimated by cancer gene panels (CGPs) has been confirmed to be associated with prognosis and is effective in predicting clinical benefit from immune checkpoint blockade (ICB) in solid tumors. However, whether the TMB calculated by CGPs is associated with overall survival (OS) for patients with diffuse large B-cell lymphoma (DLBCL) is worth exploring.MethodsThe prognostic value of panel-TMB, calculated by a panel of 69 genes (GP69), for 87 DLBCL patients in our clinical center (GDPH dataset) was explored. The results were further validated using 37 DLBCL patients from the Cancer Genome Atlas (TCGA) database (TCGA dataset).ResultsSpearman correlation analysis suggested that panel-TMB is positively correlated with the TMB calculated by whole-exome sequencing (wTMB) in the TCGA dataset (R = 0.76, P < 0.0001). Both GDPH and TCGA results demonstrated that higher panel-TMB is significantly associated with a poor OS for DLBCL patients (P < 0.05) where a panel of 13 genes was associated with poor OS, and another panel of 26 genes was correlated with a favorable OS for DLBCL patients. Further subgroup analysis indicated that higher panel-TMB had shorter OS in DLBCL patients with younger than 60 years, elevated LDH, greater than one extranodal involvement, stage III/IV, an IPI score of 3–5, or HBsAg, anti-HBc, or HBV-DNA negativity (P < 0.05). Interestingly, the nomogram model constructed by panel-TMB, stage, and IPI could individually and visually predict the 1-, 2- and 3-year OS rates of DLBCL patients.ConclusionsWe established GP69 for the evaluation of OS for Chinese DLBCL patients. panel-TMB might be a potential predictor for prognostic stratification of DLBCL patients.

Molecular profiling of Chinese R-CHOP treated DLBCL patients: Identifying a high-risk subgroup.

Diffuse large B-cell lymphoma (DLBCL) is a clinically aggressive and heterogenous disease. Although most patients can be cured by immunochemotherapy, 30% to 40% patient will ultimately develop relapsed or refractory disease. Here, we investigated the molecular landscapes of patients with diverse responses to R-CHOP. We performed capture-based targeted sequencing on baseline samples of 105 DLBCL patients using a panel consisting of 112 lymphoma-related genes. Subsequently, 81 treatment-naïve patients with measurable disease and followed for over 1 year were included for survival analysis. Collectively, the most commonly seen mutations included IGH fusion (69%), PIM1(33%), MYD88 (29%), BCL2 (29%), TP53 (29%), CD79B (25%) and KMT2D (24%). Patients with TP53 mutations were more likely to have primary refractory disease (87.0% vs 50.0%, P = .009). For those with TP53 disruptive mutations, 91.7% patients were in the primary refractory group. Interestingly, BCL-2 somatic hypermutation was only seen in patients without primary refractory disease (P = .014). In multivariate analysis, BCL-2 amplification (hazard ratio [HR] = 2.94, P = .022), B2M mutation (HR = 2.99, P = .017) and TP53 mutation (HR = 3.19, P < .001) were independently associated with shorter time to progression (TTP). Furthermore, TP53 mutations was correlated with worse overall survival (P = .049). Next, we investigated mutation landscape in patients with wild-type (WT) TP53 (n = 58) and found that patients harboring MYD88 L265P had significantly inferior TTP than those with WT or non-265P (P = .046). Our study reveals the mutation spectrum of treatment-naive Chinese DLBCL patients. It also confirms the clinical significance of TP53 mutations and indicates the prognostic value of MYD88 L265P in TP53 WT patients.

Cell-of-Origin Subtyping of Diffuse Large B-Cell Lymphoma by Using a qPCR-based Gene Expression Assay on Formalin-Fixed Paraffin-Embedded Tissues

The well-established cell-of-origin (COO) algorithm categorizes diffuse large B-cell lymphoma (DLBCL) into activated B-cell-like (ABC) and germinal center B-cell-like (GCB) subgroups through gene expression profiling. We aimed to develop and validate a qPCR-based gene expression assay to determine the COO subgroups of DLBCL with formalin-fixed paraffin-embedded (FFPE) tissue. We first established a DLBCL transcriptome database of 1,016 samples retrieved from three published datasets (GSE10846, GSE22470, and GSE31312). With this database, we identified a qPCR-based 32-gene expression signature (DLBCL-COO assay) that is significantly associated with the COO subgroups. The DLBCL-COO assay was further validated in a cohort of 160 Chinese DLBCL patients. Biopsy samples from DLBCL patients with paired FFPE and fresh frozen tissue were collected to assign COO subtypes based on the immunohistochemistry (IHC) algorithm (Han's algorithm), DLBCL-COO assay, and global gene expression profiling with RNA-seq. For 111 paired FFPE and fresh DLBCL samples, the concordance between the IHC, qPCR, and RNA-seq methods was 77.5% and 91.9%, respectively. The DLBCL-COO assay demonstrated a significantly superior concordance of COO determination with the “gold standard” RNA-seq compared with the IHC assignment with Han's algorithm (P = 0.005). Furthermore, the overall survival of GCB patients defined by the DLBCL-COO assay was significantly superior to that of ABC patients (P = 0.023). This effect was not seen when the tumors were classified by the IHC algorithm. The DLBCL-COO assay provides flexibility and accuracy in DLBCL subtype characterization. These findings demonstrated that the DLBCL-COO assay might serve as a useful tool for guiding prognostic and therapeutic options for DLBCL patients.

Immune Characteristics of Chinese Diffuse Large B-Cell Lymphoma Patients: Implications for Cancer Immunotherapies

Immunotherapeutic agents have demonstrated encouraging signs of clinical utility in non-Hodgkin lymphoma. The goal of this study is to analyze the immune characteristics of Chinese patients with diffuse large B-cell lymphoma (DLBCL) to inform the development of immunotherapies in this patient population. Tumor samples from 211 DLBCL patients were analyzed for cell of origin (COO) and immune characteristics using the NanoString platform as well as MYC protein expression through immunohistochemistry. Lower incidence of the germinal center B-cell (GCB) subtype (93/211, 44.1%) was observed in this cohort. Compared to the GCB subtype, the activated B-cell (ABC) subtype was associated with significantly increased expression of multiple pro-inflammatory gene signatures and decreased expression of anti-inflammatory gene signatures. Instead of affecting the pro-inflammatory genes, MYC protein overexpression showed a negative correlation with the expression of T-cell receptor (TCR) and T regulatory genes as well as the OX40 gene. Regardless of COO, higher PD-L1 or IDO1 gene expression correlated with increased expression of T effector and Interferon-γ gene signatures while the expression of multiple oncogenes including ACTR3B, ERBB2, AKT2 and SMARCD1 was down-regulated. Our findings may thus be helpful in guiding further development of immunotherapies for the different subsets of Chinese DLBCL patients.

CD3+/CD8+ T-cell density and tumoral PD-L1 predict survival irrespective of rituximab treatment in Chinese diffuse large B-cell lymphoma patients.

To investigate the prognostic value of tumor-infiltrating T-cell density and programmed cell death ligand-1 (PD-L1) expression in diffuse large B cell lymphoma (DLBCL). One-hundred-twenty-five Chinese DLBCL patients were enrolled in our study and provided samples; 76 of all cases were treated with rituximab (R). Tumor tissues were immunostained and analyzed for CD3+ and CD8+ tumor-infiltrating T-cell density, tumoral PD-L1, and microenvironmental PD-L1 (mPD-L1). The density of CD3 was rated as high in 33.6% cases, while 64.0% of DLBCLs were classified as high CD8 density. Of all cases, 16.8% were PD-L1+. Of the remaining PD-L1-DLBCLs, 29.8% positively expressed mPD-L1. Both CD3 high density and CD8 high density were associated with mPD-L1 positivity (P = 0.001 and P = 0.0001). In multivariate analysis, independently, high CD3 density predicted better OS (P = 0.023), while CD8 high density and PD-L1 positivity were both associated with prolonged PFS (P = 0.013 and P = 0.036, respectively). Even in the subgroup treated with R, univariate analyses indicated that high CD3 density and PD-L1 positivity were associated with better OS (P = 0.041) and PFS (P = 0.033), respectively. The infiltrating densities of CD3+ T-cells, CD8+ T-cells, and PD-L1 expression are predictive of survival in DLBCLs, irrespective of R usage.

TP53 Arg72 as a favorable prognostic factor for Chinese diffuse large B-cell lymphoma patients treated with CHOP

BackgroundTP53 Arg72Pro (SNP rs1042522) is associated with risk of non-Hodgkin lymphoma (NHL). Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of NHL. However, the relationship between this SNP and prognosis of DLBCL in Asians is unknown.MethodsGenotyping of TP53 Arg72Pro was done in 425 Chinese DLBCL patients. Two hundred and eighty-nine patients were treated with R-CHOP, and 136 patients received CHOP or CHOP-like as frontline regimen. Three hundred and ninety-six patients were assessable for the efficacy.ResultsPatients with Arg/Arg and Arg/Pro at codon 72 of TP53 had a higher complete response rate (61% vs. 44%, P = 0.007) than those with Pro/Pro. In the subgroup treated with CHOP or CHOP-like therapy, patients with Arg/Arg and Arg/Pro showed a higher 5-year overall survival (OS) rate than those with Pro/Pro (68.8% vs. 23.2%, P = 0.001). Multivariate Cox regression analysis revealed TP53 Arg72 as a favorable prognostic factor in this group. However, the combination of rituximab with CHOP significantly increased the 5-year OS rate of patients with Pro/Pro to 63%.ConclusionThis study revealed TP53 Arg72 as a favorable prognostic factor for Chinese DLBCL patients treated with CHOP or CHOP-like as frontline therapy.

The expression and clinical relevance of PD-1, PD-L1, and TP63 in patients with diffuse large B-cell lymphoma.

Latest study showed that a novel translocation between programmed cell death ligand 1 (PD-L1) (cluster of differentiation 274) and TP63 (tumor protein 63) can be found in diffuse large B-cell lymphoma (DLBCL), resulting in their conjunct overexpression in tumor cells at RNA level. However, the expressed pattern of these 2 genes at protein level in DLBCL remains largely unknown, and the clinical relevance of PD-L1 and TP63 expression in DLBCL are also unclear.Tumor tissues from 76 Chinese DLBCL patients were immunostained for programmed cell death 1 (PD-1), PD-L1, and TP63 using the EnVision system. Clinical relevance of PD-1, PD-L1, and TP63 in 74 DLBCL were analyzed by chi-square test, the Kaplan-Meier curves with log rank test, and Cox's proportional hazards regression model.PD-1 was mainly expressed in tumor-infiltrating lymphocytes (TILs) of 39.5% patients. PD-L1 was expressed in tumor cells of 26.3% patients, and TP63 was immunostained in nucleoli of tumor cells of 31.6% cases. PD-1 expression was significantly associated with the patients' gender and B symptoms (P = 0.032, P = 0.026). DLBCL with PD-L1 or TP63 expression in tumor cells showed low International Prognostic Index (IPI) score (P = 0.007, P = 0.009). PD-1 TILs was related to prolonged overall survival rate (OS) of DLBCL patients (P = 0.02), whereas PD-L1 expression was associated with worse clinical outcome of patients (P = 0.049). Immunoreactivity of TP63 was not correlated with patients' survival time. Besides, PD-1 expression, patients' age, Ann Arbor stage, and IPI score were significant prognostic markers for OS, but PD-L1 and TP63 had no prognostic significance.PD-1, PD-L1, and TP63 are frequently expressed in DLBCL. PD-1/PD-L1/TP63 blockade may be a potential therapeutic strategy for some patients.

B-cell Function Gene Mutations in Diffuse Large B-cell Lymphoma: A Retrospective Cohort Study

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous subtype of non-Hodgkin lymphoma. In addition to clinical and immunophenotypic characteristics, recurrent gene mutations have recently been identified in patients with DLBCL using next-generation sequencing technologies. The aim of this study is to investigate the clinical relevance of B-cell function gene mutations in DLBCL. Clinical analysis was performed on 680 Chinese DLBCL patients (146 non-CR and 534 CR cases) treated with six cycles of 21-day R-CHOP (Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), alone or followed by two additional doses of rituximab consolidation on patients' own intention. Somatic mutations of B-cell function genes were further screened on 275 (71 non-CR and 204 CR) cases with available tumor samples by targeted sequencing, including genes involved in B-cell receptors (BCRs) pathway (CARD11, LYN, CD79A, and CD79B), Toll-like receptors (TLRs) pathway (MYD88), and tumor necrotic factor receptor (TNFR) pathway (TRAF2 and TNFAIP3). B-cell function gene mutations occurred in 44.0% (121/275) of DLBCL patients. The TLRs and TNFR related gene mutations were more frequently observed in non-CR patients (p=0.019 and p=0.032, respectively). BCRs related gene mutations, as well as revised IPI (R-IPI) and double BCL-2/MYC expression, were independently related to short progression-free survival in DLBCL after CR. The adverse prognostic effect of BCRs related gene mutations could be overcome by two additional doses of rituximab consolidation. These results highlight the molecular heterogeneity of DLBCL and identify a significant role of B-cell function gene mutations on lymphoma progression and response to rituximab in DLBCL.

PP-082 DELAYED ENGRAFTMENT DUE TO CANDIDA NORVEGENSIS IN HDC AND SCT PATIENT

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous subtype of non-Hodgkin lymphoma. In addition to clinical and immunophenotypic characteristics, recurrent gene mutations have recently been identified in patients with DLBCL using next-generation sequencing technologies. The aim of this study is to investigate the clinical relevance of B-cell function gene mutations in DLBCL. Clinical analysis was performed on 680 Chinese DLBCL patients (146 non-CR and 534 CR cases) treated with six cycles of 21-day R-CHOP (Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), alone or followed by two additional doses of rituximab consolidation on patients' own intention. Somatic mutations of B-cell function genes were further screened on 275 (71 non-CR and 204 CR) cases with available tumor samples by targeted sequencing, including genes involved in B-cell receptors (BCRs) pathway (CARD11, LYN, CD79A, and CD79B), Toll-like receptors (TLRs) pathway (MYD88), and tumor necrotic factor receptor (TNFR) pathway (TRAF2 and TNFAIP3). B-cell function gene mutations occurred in 44.0% (121/275) of DLBCL patients. The TLRs and TNFR related gene mutations were more frequently observed in non-CR patients (p = 0.019 and p = 0.032, respectively). BCRs related gene mutations, as well as revised IPI (R-IPI) and double BCL-2/MYC expression, were independently related to short progression-free survival in DLBCL after CR. The adverse prognostic effect of BCRs related gene mutations could be overcome by two additional doses of rituximab consolidation. These results highlight the molecular heterogeneity of DLBCL and identify a significant role of B-cell function gene mutations on lymphoma progression and response to rituximab in DLBCL.

PP-083 SECONDARY ALL IN MULTIPLE MYELOMA PATIENT WHO UNDERWENT HDC AND SCT

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous subtype of non-Hodgkin lymphoma. In addition to clinical and immunophenotypic characteristics, recurrent gene mutations have recently been identified in patients with DLBCL using next-generation sequencing technologies. The aim of this study is to investigate the clinical relevance of B-cell function gene mutations in DLBCL. Clinical analysis was performed on 680 Chinese DLBCL patients (146 non-CR and 534 CR cases) treated with six cycles of 21-day R-CHOP (Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), alone or followed by two additional doses of rituximab consolidation on patients' own intention. Somatic mutations of B-cell function genes were further screened on 275 (71 non-CR and 204 CR) cases with available tumor samples by targeted sequencing, including genes involved in B-cell receptors (BCRs) pathway (CARD11, LYN, CD79A, and CD79B), Toll-like receptors (TLRs) pathway (MYD88), and tumor necrotic factor receptor (TNFR) pathway (TRAF2 and TNFAIP3). B-cell function gene mutations occurred in 44.0% (121/275) of DLBCL patients. The TLRs and TNFR related gene mutations were more frequently observed in non-CR patients (p = 0.019 and p = 0.032, respectively). BCRs related gene mutations, as well as revised IPI (R-IPI) and double BCL-2/MYC expression, were independently related to short progression-free survival in DLBCL after CR. The adverse prognostic effect of BCRs related gene mutations could be overcome by two additional doses of rituximab consolidation. These results highlight the molecular heterogeneity of DLBCL and identify a significant role of B-cell function gene mutations on lymphoma progression and response to rituximab in DLBCL.

Chromosome abnormalities in diffuse large B‐cell lymphomas: analysis of 231 Chinese patients

Genome instability is a hallmark of cancer. Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma with high levels of chromosomal aberrations. The purpose of this study was to characterize chromosomal aberrations in Chinese DLBCL patients and to compare chromosomal abnormalities between germinal centre B-cell-like (GCB) and non-GCB subgroups. Fluorescence in situ hybridization, G-band cytogenetics and immunohistochemistry were performed in 231 cases of de novo DLBCL. We demonstrated that the rate of abnormal and complex karyotypes was 89.1% (139/156) and 92.8% (129/139), respectively. We found a total of 490 structural chromosomal aberrations, including 96 frequent and recurring structural alterations. Most importantly, we identified several rare or novel chromosomal alterations: eight gains (5, 13, 14q, 17, 19p, 20, 21p, Y), one loss (21) and three recurrent translocations [t(7;15)(q22;q22), t(3;20)(p24;q13.1), t(2;3)(q21;q25)]. Moreover, the frequent recurrent genomic imbalance between GCB and non-GCB subgroups was different. Finally, we discovered two cases of concurrent IGH-BCL6 and MYC rearrangements. The rate of abnormal karyotypes in DLBCL patients of Chinese descent was similar to that of Western countries, but some common karyotypes were different, as were the abnormal karyotypes of GCB and non-GCB subgroups. Our discovery of rare and novel abnormal karyotypes may represent unique chromosomal alterations in Chinese DLBCL patients.

High expression of cell division cycle 7 protein correlates with poor prognosis in patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma. According to the clinical risk factors and biological heterogeneity, clinical outcome of DLBCL is extremely various, with 5-year survival rates between 30 and 80 %. Although the International Prognostic Index (IPI) remains the primary clinical tool used to predict outcome for patients with DLBCL, notable variability in outcome is still observed within the same IPI score. The cell division cycle 7 (CDC7) is a serine-threonine kinase, which is required to initiate DNA replication. Study showed that high expression of CDC7 was correlated with poor prognosis in patients with DLBCL. Whether CDC7 is an independent prognostic factor for DLBCL remains debatable. We studied the expression of CDC7 protein in 60 Chinese DLBCL patients with immunohistochemical analysis, 34 patients (56.7 %) categorized as low CDC7 expression and 26 patients (43.3 %) as high CDC7 expression. The median survival time of patients with low CDC7 expression was not achieved and that of high expression was 9 months (P = 0.027). A multivariate analysis showed that IPI score and Ann Arbor stage were independent prognostic factors in relation to patients' OS (P < 0.05). Pearson correlation analysis showed that CDC7 expression level was positively correlated with IPI score and Ann Arbor stage (P < 0.001). The results suggest that CDC7 expression level in combination with IPI score and Ann Arbor stage can be specific prognostic factors for DLBCL patients. CDC7 could also be a potential therapeutic target in DLBCL, especially for ABC-DLBCL.

The prognostic value of immunohistochemical subtyping in Chinese patients with de novo diffuse large B-cell lymphoma undergoing CHOP or R-CHOP treatment

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with recognised variability in molecular aetiology and clinical outcome. Though the use of agents such as rituximab significantly improves outcome, intrinsic genetic and morphological factors greatly affect the response to treatment. The objective of this study was to evaluate the prognostic value of immunohistochemical subtyping and the International Prognostic Index (IPI) for predicting treatment outcome in Chinese DLBCL patients. We followed 108 cases of DLBCL and performed prognostic analyses based on molecular subtyping of the disease through immunostaining of tissue samples. The use of rituximab conferred a clinical benefit to DLBCL patients regardless of disease subtype. Importantly, this treatment regimen also improved outcomes in patients with the non-germinal centre B-cell-like (GCB) DLBCL subtype, frequently associated with poorer prognosis. Our results suggest that IPI was the best tool for the prediction of treatment outcome in our patient cohort, regardless of treatment regimen. Furthermore, the use of rituximab alongside classical chemotherapy regimens can improve the outcomes for DLBCL patients who exhibit both GCB and non-GCB subtypes of the disease.

Higher incidence of Simian virus 40 in primary gastric diffuse large B cell lymphoma (DLBCL) than primary nodal disease in Chinese patients, but of no prognostic implication

6671 Background: Studies have reported the detection of simian polyomavirus SV40 DNA sequence in 10–40% of non-Hodgkin's lymphoma patients and there is compelling evidence that SV40 may contribute to the oncogenesis in human. However, its incidence in Chinese patients, prognostic implication and site predilection are largely unknown. Methods: We analysed the diagnostic histological specimens from 49 Chinese patients with diffuse large B cell lymphoma diagnosed from 1989 to 1996. PCR followed by Southern blot hybridization were performed and SV 40 specific DNA was confirmed by DNA sequencing. Results: Among the 49 patients (M:F=28:21; mean age=58 years, range 22–83), there were 7 cases (14%) positive for SV 40 by PCR and 6 of them were confirmed to be SV 40 specific DNA, giving an incidence of 12%. Primary sites were peripheral lymph node (n=30, 61%), gastric (n=18, 37%) and sternal soft tissue (n=1, 2%). Primary gastric lymphoma had a significantly higher SV40 positivity rate than the nodal disease (5/18, 28% versus 1/30, 3.3%; p=0.02) There was no difference between the SV40 positive and SV 40 negative patients in terms of mean age (51 versus 59), IPI score (2.5 versus 1.9), LDH level (565 versus 675), no. of chemotherapy regimens (6.17 versus 6.3) and first complete remission (CR) rate (67% versus 58%). With a median follow up of 3 years, 31 (63%) patients died (4/6 in SV40 positive versus 27/43 in negative, p=not significant). The overall median survival was 51 months with no difference between SV40 positive and negative cases (53 versus 39 months). Conclusions: SV40 was found at low incidence rate of 12% in Chinese DLBCL patients and it had no prognostic values. However, there was a significant association with gastric lymphoma. Further investigations should be done to study its possible etiological role. No significant financial relationships to disclose.

Higher incidence of Simian virus 40 in primary gastric diffuse large B cell lymphoma (DLBCL) than primary nodal disease in Chinese patients, but of no prognostic implication

6671 Background: Studies have reported the detection of simian polyomavirus SV40 DNA sequence in 10–40% of non-Hodgkin's lymphoma patients and there is compelling evidence that SV40 may contribute to the oncogenesis in human. However, its incidence in Chinese patients, prognostic implication and site predilection are largely unknown. Methods: We analysed the diagnostic histological specimens from 49 Chinese patients with diffuse large B cell lymphoma diagnosed from 1989 to 1996. PCR followed by Southern blot hybridization were performed and SV 40 specific DNA was confirmed by DNA sequencing. Results: Among the 49 patients (M:F=28:21; mean age=58 years, range 22–83), there were 7 cases (14%) positive for SV 40 by PCR and 6 of them were confirmed to be SV 40 specific DNA, giving an incidence of 12%. Primary sites were peripheral lymph node (n=30, 61%), gastric (n=18, 37%) and sternal soft tissue (n=1, 2%). Primary gastric lymphoma had a significantly higher SV40 positivity rate than the nodal disease (5/18, 28% versus 1/30, 3.3%; p=0.02) There was no difference between the SV40 positive and SV 40 negative patients in terms of mean age (51 versus 59), IPI score (2.5 versus 1.9), LDH level (565 versus 675), no. of chemotherapy regimens (6.17 versus 6.3) and first complete remission (CR) rate (67% versus 58%). With a median follow up of 3 years, 31 (63%) patients died (4/6 in SV40 positive versus 27/43 in negative, p=not significant). The overall median survival was 51 months with no difference between SV40 positive and negative cases (53 versus 39 months). Conclusions: SV40 was found at low incidence rate of 12% in Chinese DLBCL patients and it had no prognostic values. However, there was a significant association with gastric lymphoma. Further investigations should be done to study its possible etiological role. No significant financial relationships to disclose.