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Purpose This study evaluated the predictive significance of total metabolic tumour volume (TMTV) measured on baseline FDG PET/CT and its value in addition to gene expression profiling using a new method of gene analysis (rapid reverse transcriptase multiplex ligation-dependent probe amplification assay, RT-MLPA) in patients with diffuse large B-cell lymphoma treated with R-CHOP or R-CHOP-like chemotherapies. Methods The analysis included 114 patients. TMTV was measured using a 41% SUVmax threshold and tumours were classified into GCB or ABC subtypes according to the RT-MLPA assay. Results The median follow-up was 40 months. the 5-year progression-free survival (PFS) was 54% and the 5-year overall survival (OS) was 62%. The optimal TMTV cut-off value was 261 cm³. In 59 patients with a high TMTV the 5-year PFS and OS were 37% and 39%, respectively, in comparison with 72% and 83%, respectively, in 55 patients with a low TMTV (p = 0.0002 for PFS, p < 0.0001 for OS). ABC status was significantly associated with a worse prognosis. TMTV combined with molecular data identified three groups with very different outcomes: (1) patients with a low TMTV whatever their phenotype (n = 55), (2) patients with a high TMTV and GCB phenotype (n = 33), and (3) patients with a high TMTV and ABC phenotype (n = 26). In the three groups, 5-year PFS rates were 72%, 51% and 17% (p < 0.0001), and 5-year OS rates were 83%, 55% and 17% (p < 0.0001), respectively. In multivariate analysis, TMTV, ABC/GCB phenotype and International Prognostic Index were independent predictive factors for both PFS and OS (p < 0.05 for both). Conclusions This integrated risk model could lead to more accurate selection of patients that would allow better individualization of therapy. [ABSTRACT FROM AUTHOR]

Background Diffuse large B-cell lymphomas (DLBCLs) arising in specific extranodal sites have peculiar clinicopathologic features. Patients and methods We analyzed a cohort of 187 primary Waldeyer's ring (WR) DLBCLs retrieved from GELA protocols using anthracyclin-based polychemotherapy. Results Most patients (92%) had stage I–II disease. A germinal center B-cell-like (GCB) immunophenotype was observed in 61%, and BCL2 expression in 55%, of WR DLBCLs. BCL2, BCL6, IRF4 and MYC breakpoints were observed in, respectively, 3 of 42 (7%), 9 of 36 (25%), 2 of 26 (8%) and 4 of 40 (10%) contributive cases. A variable follicular pattern was evidenced in 30 of 68 (44%) large biopsy specimens. The 5-year progression-free survival (PFS) and the overall survival (OS) of 153 WR DLBCL patients with survival information were 69.5% and 77.8%, respectively. The GCB immunophenotype correlated with a better OS (P = 0.0015), while BCL2 expression predicted a worse OS (P = 0.037), an effect overcome by the GCB/non-GCB classification. Compared with matched nodal DLBCLs, WR DLBCLs with no age-adjusted international prognostic index factor disclosed a better 5-year PFS rate (77.5% versus 70.7%; P = 0.03). Conclusions WR DLBCLs display distinct clinicopathologic features compared with conventional DLBCLs, with usual localized-stage disease, common follicular features and a high frequency of GCB immunophenotype contrasting with a low rate of BCL2 rearrangements. In addition, they seem to be associated with a better outcome than their nodal counterpart. [ABSTRACT FROM PUBLISHER]

Gene expression profiling has identified two major molecular subtypes of diffuse large B-cell lymphoma (DLBCL) that are histologically indistinguishable but differ in cure rates. Here, we investigated whether the isotype of the B-cell receptor (BCR) expressed by the tumoral cells correlated with the molecular subtype and survival. Gene expression analysis clustered the 53 patients included in this study into three subgroups, 17 germinal center B-cell-like (GCB) cases, 26 activated B-cell-like (ABC) cases and 10 intermediate cases. The molecular subtype was correlated with the isotype, as 15/17 GCB cases expressed a secondary isotype (immunoglobulin (Ig)G or IgA), whereas 24/26 ABC cases expressed a primary isotype (IgM or IgD) (P<0.0001). There was a trend toward a worse outcome for patients with an ABC DLBCL and a shorter overall survival for patients with IgM+ tumor (P=0.21 and 0.014, respectively). Finally, fluorescence in situ hybridization (FISH) analysis revealed a striking asymmetric pattern, as the IGHM gene is conserved only on the productive IGH allele in most IgM+ tumors. Taken together, these data indicate that the isotype of the BCR is a reliable indicator for the GCB and ABC subtypes in DLBCL, and suggest that the conservation of an IgM is required for ABC DLBCL lymphomagenesis to occur. [ABSTRACT FROM AUTHOR]

Follicular lymphoma (FL) B cells contract tight connections with their microenvironment, which governs the pathogenesis and progression of the disease. Indeed, specific immune response gene signatures, obtained from whole biopsy samples, have been associated with patient survival. In this study, we performed gene expression profiling of purified B cell and non-B cell compartments obtained from FL and reactive lymph nodes. We identified 677 non-redundant genes defining the FL interface and involving 26 FL-specific functional networks. This approach highlighted an interleukin-4 (IL-4)-centered pathway associated with an activation of signal transducer and activator of transcription 6 (STAT6), which favors overexpression of IL-4-target genes. In addition, FL microenvironment was characterized by a strong enrichment in follicular helper T cells (T(FH)), as demonstrated through transcriptomic and flow cytometry analyses. The majority of phospho-STAT6(pos) B cells were located at the vicinity of cells expressing the programmed death 1 (PD-1) T(FH) marker. Moreover, purified FL-derived T(FH), expressed IL4 at very high levels compared with purified tonsil-derived T(FH) or non-T(FH) microenvironment. Altogether, our study demonstrated that tumor-infiltrating T(FH) specifically express functional IL-4 in FL, creating an IL-4-dependent T(FH)-B cell axis. This cross talk could sustain FL pathogenesis and represent a new potential therapeutic target. [ABSTRACT FROM AUTHOR]

Gene expression profiles have been associated with clinical outcome in patients with diffuse large B-cell lymphoma (DLBCL) treated with anthracycline-containing chemotherapy. Using Affymetrix HU133A microarrays, we analyzed the lymphoma transcriptional profile of 30 patients treated with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) and 23 patients treated with rituximab (R)-CHOP in the Groupe d'Etude des Lymphomes de l'Adulte clinical centers. We used this data set to select transcripts showing an association with progression-free survival in all patients or showing a differential effect in the two treatment groups. We performed real-time quantitative reverse transcription-PCR in the 23 R-CHOP samples of the screening set and an additional 44 R-CHOP samples set to evaluate the prognostic significance of these transcripts. In these 67 patients, the level of expression of 16 genes and the cell-of-origin classification were significantly associated with overall survival, independently of the International Prognostic Index. A multivariate model comprising four genes of the cell-of-origin signature (LMO2, MME, LPP and FOXP1) and two genes related to immune response, identified for their differential effects in R-CHOP patients (APOBEC3G and RAB33A), demonstrated a high predictive efficiency in this set of patients, suggesting that both features affect outcome in DLBCL patients receiving immunochemotherapy. [ABSTRACT FROM AUTHOR]

Chromosomal translocations joining the immunoglobulin (IG) and MYC genes have been extensively reported in Burkitt's and non-Burkitt's lymphomas but data concerning MYC rearrangements with non-IG partners are scarce. In this study, 8q24 breakpoints from 17 B-cell lymphomas involving non-IG loci were mapped by fluorescence in situ hybridization (FISH). In seven cases the breakpoint was inside a small region encompassing MYC: in one t(7;8)(p12;q24) and two t(3;8)(q27;q24), it was telomeric to MYC whereas in four cases, one t(2;8)(p15;q24) and three t(8;9)(q24;p13) it was located in a 85 kb region encompassing MYC. In these seven cases, partner regions identified by FISH contained genes known to be involved in lymphomagenesis, namely BCL6, BCL11A, PAX5 and IKAROS. Breakpoints were cloned in two t(8;9)(q24;p13), 2.5 and 7 kb downstream from MYC and several hundred kb 5' to PAX5 on chromosome 9, joining MYC to ZCCHC7 and to ZBTB5 exon 2, two genes encoding zinc-finger proteins. In these seven cases, MYC expression measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) was significantly higher when compared to that of patients without 8q24 rearrangement (P=0.006). These results suggest that these rearrangements are the consequence of a non-random process targeting MYC together with non-IG genes involved in lymphocyte differentiation and lymphoma progression. [ABSTRACT FROM AUTHOR]