Molecular features of a large cohort of primary central nervous system lymphoma using tissue microarray.

The objective of this study was to evaluate the distribution and prognostic impact of a broad range of molecular attributes in a large cohort of immunocompetent patients with primary central nervous system lymphoma (PCNSL) by using tissue microarray. Patients diagnosed with PCNSL were initially identified in the BC Cancer Lymphoid Cancer clinical and pathology databases. Tissue microarrays were constructed by using archival formalin-fixed paraffin-embedded diagnostic biopsy tissue. Immunohistochemistry and fluorescent in situ hybridization studies were performed. A total of 115 patients with PCNSL with diffuse large B-cell lymphoma (DLBCL) histology were identified. The majority of cases (≥75%) had a non-germinal center B-cell phenotype according to immunohistochemistry algorithms, but cell of origin did not affect progression-free or overall survival. MYC (40%), BCL2 (75%), and programmed death-ligand 1 (29%) protein expression were common, but their corresponding gene rearrangements were rare (≤1% each), suggesting that alternate mechanisms were driving expression. There were no dual rearrangements involving MYC and BCL2. Only 22% of cases had membranous expression of major histocompatibility complex class II, suggesting a mechanism for escape from immune surveillance. Epstein-Barr virus-encoded RNA was positive in 1 immunocompetent patient. BCL6 protein expression (77%) and BCL6 rearrangements (31%) were frequent; the latter was the only factor associated with a poor prognosis in the overall cohort and in the subgroup of 52 patients treated with high-dose methotrexate-based regimens. This large population-based study shows that prominent molecular features of PCNSL are unique and different from those of systemic DLBCL. These results may better inform drug development in PCNSL.

Antemortem histopathology and imaging findings in a case of Marchiafava-Bignami disease.

Marchiafava-Bignami disease (MBD) is a rare condition often associated with chronic alcohol abuse. Clinical presentation is diverse. Characteristic magnetic resonance imaging (MRI) changes in the corpus callosum are the mainstay of radiological diagnosis. We present a case of a 54-year-old man with chronic alcoholism and peripherally enhancing lesion in the body of the corpus callosum on MRI Brain. Open biopsy of the lesion showed necrosis and demyelination. He was diagnosed with Marchiafava-Bignami disease based on clinical, radiology and histopathology findings. Our case represents the only case in the literature with antemortem histopathology findings describing MBD.

Impact of dual expression of MYC and BCL2 by immunohistochemistry on the risk of CNS relapse in DLBCL.

Dual expression of MYC and BCL2 by immunohistochemistry (IHC) is associated with poor outcome in diffuse large B-cell lymphoma (DLBCL). Dual translocation of MYC and BCL2, so-called "double-hit lymphoma," has been associated with a high risk of central nervous system (CNS) relapse; however, the impact of dual expression of MYC and BCL2 (dual expressers) on the risk of CNS relapse remains unknown. Pretreatment formalin-fixed paraffin-embedded DLBCL biopsies derived from patients subsequently treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were assembled on tissue microarrays from 2 studies and were evaluated for expression of MYC and BCL2 by IHC. In addition, cell of origin was determined by IHC and the Lymph2Cx gene expression assay in a subset of patients. We identified 428 patients who met the inclusion criteria. By the recently described CNS risk score (CNS-International Prognostic Index [CNS-IPI]), 34% were low risk (0 to 1), 45% were intermediate risk (2 to 3), and 21% were high risk (4 or greater). With a median follow-up of 6.8 years, the risk of CNS relapse was higher in dual expressers compared with non-dual expressers (2-year risk, 9.7% vs 2.2%; P = .001). Patients with activated B-cell or non-germinal center B-cell type DLBCL also had an increased risk of CNS relapse. However, in multivariate analysis, only dual expresser status and CNS-IPI were associated with CNS relapse. Dual expresser MYC(+) BCL2(+) DLBCL defines a group at high risk of CNS relapse, independent of CNS-IPI score and cell of origin. Dual expresser status may help to identify a high-risk group who should undergo CNS-directed evaluation and consideration of prophylactic strategies.

Recurrent genomic rearrangements in primary testicular lymphoma.

Primary testicular diffuse large B cell lymphoma (PTL) is an aggressive malignancy that occurs in the immune-privileged anatomical site of the testis. We have previously shown that structural genomic rearrangements involving the MHC class II transactivator CIITA and programmed death ligands (PDLs) 1 and 2 are frequent across multiple B cell lymphoma entities. Specifically in PTL, we found rearrangements in the PDL locus by fluorescence in situ hybridization (FISH). However, breakpoint anatomy and rearrangement partners were undetermined, while CIITA rearrangements had not been reported previously in PTL. Here, we performed bacterial artificial chromosome capture sequencing on three archival, formalin-fixed, paraffin-embedded tissue biopsies, interrogating 20 known rearrangement hotspots in B cell lymphomas. We report novel CIITA, FOXP1 and PDL rearrangements involving IGHG4, FLJ45248, RFX3, SMARCA2 and SNX29. Moreover, we present immunohistochemistry data supporting the association between PDL rearrangements and increased protein expression. Finally, using FISH, we show that CIITA (8/82; 10%) and FOXP1 (5/74; 7%) rearrangements are recurrent in PTL. In summary, we describe rearrangement frequencies and novel rearrangement partners of the CIITA, FOXP1 and PDL loci at base-pair resolution in a rare, aggressive lymphoma. Our data suggest immune-checkpoint inhibitor therapy as a promising intervention for PTL patients harbouring PDL rearrangements.

Recurrent somatic mutations of PTPN1 in primary mediastinal B cell lymphoma and Hodgkin lymphoma.

Classical Hodgkin lymphoma and primary mediastinal B cell lymphoma (PMBCL) are related lymphomas sharing pathological, molecular and clinical characteristics. Here we discovered by whole-genome and whole-transcriptome sequencing recurrent somatic coding-sequence mutations in the PTPN1 gene. Mutations were found in 6 of 30 (20%) Hodgkin lymphoma cases, in 6 of 9 (67%) Hodgkin lymphoma-derived cell lines, in 17 of 77 (22%) PMBCL cases and in 1 of 3 (33%) PMBCL-derived cell lines, consisting of nonsense, missense and frameshift mutations. We demonstrate that PTPN1 mutations lead to reduced phosphatase activity and increased phosphorylation of JAK-STAT pathway members. Moreover, silencing of PTPN1 by RNA interference in Hodgkin lymphoma cell line KM-H2 resulted in hyperphosphorylation and overexpression of downstream oncogenic targets. Our data establish PTPN1 mutations as new drivers in lymphomagenesis.

Genomic rearrangements involving programmed death ligands are recurrent in primary mediastinal large B-cell lymphoma.

The pathogenesis of primary mediastinal large B-cell lymphoma (PMBCL) is incompletely understood. Recently, specific genotypic and phenotypic features have been linked to tumor cell immune escape mechanisms in PMBCL. We studied 571 B-cell lymphomas with a focus on PMBCL. Using fluorescence in situ hybridization here, we report that the programmed death ligand (PDL) locus (9p24.1) is frequently and specifically rearranged in PMBCL (20%) as compared with diffuse large B-cell lymphoma, follicular lymphoma, and Hodgkin lymphoma. Rearrangement was significantly correlated with overexpression of PDL transcripts. Utilizing high-throughput sequencing techniques, we characterized novel translocations and chimeric fusion transcripts involving PDLs at base-pair resolution. Our data suggest that recurrent genomic rearrangement events underlie an immune privilege phenotype in a subset of B-cell lymphomas.

MYC and BCL2 protein expression predicts survival in patients with diffuse large B-cell lymphoma treated with rituximab.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease and "double-hit" DLBCL, with both MYC and BCL2 translocations has a poor prognosis. In this study, we investigated whether MYC and BCL2 protein expression in tissue would predict survival in DLBCL. The study included 106 cases of de novo DLBCL treated with rituximab and cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or CHOP-like regimens. The results were validated on an independent cohort of 205 DLBCL patients. Patients with low expression of BCL2 (≤30%) and MYC (≤50%) had the best prognosis, whereas those with high BCL2 (>30%) and MYC (>50%) had the worst outcome. In multivariate analysis, the combination of the BCL2 and MYC was an independent predictor of overall survival (OS) and event-free survival (EFS) (P = 0·015 and P = 0·005, respectively). The risk of death was nine times greater for patients with high BCL2 and MYC compared to those with low expression. High BCL2 and MYC was a strong predictor of poor OS (P < 0·001) and EFS (P = 0·0017) in patients with the germinal centre B-cell (GCB) type, but not in the non-GCB type. In DLBCL, high co-expression of MYC and BCL2 was an independent predictor of poor survival, and could be used to stratify patients for risk-adapted therapies.

Plasma Epstein-Barr virus DNA predicts outcome in advanced Hodgkin lymphoma: correlative analysis from a large North American cooperative group trial.

Epstein-Barr virus (EBV) is associated with Hodgkin lymphoma (HL) and can be detected by in situ hybridization (ISH) of viral nucleic acid (EBER) in tumor cells. We sought to determine whether plasma EBV-DNA could serve as a surrogate for EBER-ISH and to explore its prognostic utility in HL. Specimens from the Cancer Cooperative Intergroup Trial E2496 were used to compare pretreatment plasma EBV-DNA quantification with EBV tumor status by EBER-ISH. A cutoff of >60 viral copies/100 µL plasma yielded 96% concordance with EBER-ISH. Pretreatment and month 6 plasma specimens were designated EBV(-) or EBV(+) by this cutoff. Patients with pretreatment EBV(+) plasma (n = 54) had inferior failure-free survival (FFS) compared with those with pretreatment EBV(-) plasma (n = 274), log-rank P = .009. By contrast, no difference in FFS was observed when patients were stratified by EBER-ISH. Pretreatment plasma EBV positivity was an independent predictor of treatment failure on multivariate analyses. At month 6, plasma EBV(+) patients (n = 7) had inferior FFS compared with plasma EBV(-) patients (n = 125), log-rank P = .007. These results confirm that plasma EBV-DNA is highly concordant with EBER-ISH in HL and suggest that it may have prognostic utility both at baseline and after therapy. This trial was registered at www.clinicaltrials.gov as #NCT00003389.

Gene expression-based model using formalin-fixed paraffin-embedded biopsies predicts overall survival in advanced-stage classical Hodgkin lymphoma.

PURPOSE: Our aim was to reliably identify patients with advanced-stage classical Hodgkin lymphoma (cHL) at increased risk of death by developing a robust predictor of overall survival (OS) using gene expression measured in routinely available formalin-fixed paraffin-embedded tissue (FFPET). METHODS: Expression levels of 259 genes, including those previously reported to be associated with outcome in cHL, were determined by digital expression profiling of pretreatment FFPET biopsies from 290 patients enrolled onto the E2496 Intergroup trial comparing doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and Stanford V regimens in locally extensive and advanced-stage cHL. A model for OS separating patients into low- and high-risk groups was produced using penalized Cox regression. The model was tested in an independent cohort of 78 patients enriched for treatment failure but otherwise similar to patients in a population-based registry of patients treated with ABVD. Weighted analysis methods generated unbiased estimates of predictor performance in the population-based registry. RESULTS: A 23-gene outcome predictor was generated. The model identified a population at increased risk of death in the validation cohort. There was a 29% absolute difference in 5-year OS between the high- and low-risk groups (63% v 92%, respectively; log-rank P < .001; hazard ratio, 6.7; 95% CI, 2.6 to 17.4). The predictor was superior to the International Prognostic Score and CD68 immunohistochemistry in multivariate analyses. CONCLUSION: A gene expression-based predictor, developed in and applicable to routinely available FFPET biopsies, identifies patients with advanced-stage cHL at increased risk of death when treated with standard-intensity up-front regimens.

Tumor-associated macrophages predict inferior outcomes in classic Hodgkin lymphoma: a correlative study from the E2496 Intergroup trial.

Increased tumor-associated macrophages (TAMs) are reported to be associated with poor prognosis in classic Hodgkin lymphoma (CHL). We investigated the prognostic significance of TAMs in the E2496 Intergroup trial, a multicenter phase 3 randomized controlled trial comparing ABVD and Stanford V chemotherapy in locally extensive and advanced stage CHL. Tissue microarrays were constructed from formalin-fixed, paraffin-embedded tumor tissue and included 287 patients. Patients were randomly assigned into training (n = 143) and validation (n = 144) cohorts. Immunohistochemistry for CD68 and CD163, and in situ hybridization for EBV-encoded RNA were performed. CD68 and CD163 IHC were analyzed by computer image analysis; optimum thresholds for overall survival (OS) were determined in the training cohort and tested in the independent validation cohort. Increased CD68 and CD163 expression was significantly associated with inferior failure-free survival and OS in the validation cohort. Increased CD68 and CD163 expression was associated with increased age, EBV-encoded RNA positivity, and mixed cellularity subtype of CHL. Multivariate analysis in the validation cohort showed increased CD68 or CD163 expression to be significant independent predictors of inferior failure-free survival and OS. We demonstrate the prognostic significance of TAMs in locally extensive and advanced-stage CHL in a multicenter phase 3 randomized controlled clinical trial.

Concurrent expression of MYC and BCL2 in diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone.

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) is curable in 60% of patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). MYC translocations, with or without BCL2 translocations, have been associated with inferior survival in DLBCL. We investigated whether expression of MYC protein, with or without BCL2 protein expression, could risk-stratify patients at diagnosis. PATIENTS AND METHODS: We determined the correlation between presence of MYC and BCL2 proteins by immunohistochemistry (IHC) with survival in two independent cohorts of patients with DLBCL treated with R-CHOP. We further determined if MYC protein expression correlated with high MYC mRNA and/or presence of MYC translocation. RESULTS: In the training cohort (n = 167), MYC and BCL2 proteins were detected in 29% and 44% of patients, respectively. Concurrent expression (MYC positive/BCL2 positive) was present in 21% of patients. MYC protein correlated with presence of high MYC mRNA and MYC translocation (both P < .001), but the latter was less frequent (both 11%). MYC protein expression was only associated with inferior overall and progression-free survival when BCL2 protein was coexpressed (P < .001). Importantly, the poor prognostic effect of MYC positive/BCL2 positive was validated in an independent cohort of 140 patients with DLBCL and remained significant (P < .05) after adjusting for presence of high-risk features in a multivariable model that included elevated international prognostic index score, activated B-cell molecular subtype, and presence of concurrent MYC and BCL2 translocations. CONCLUSION: Assessment of MYC and BCL2 expression by IHC represents a robust, rapid, and inexpensive approach to risk-stratify patients with DLBCL at diagnosis.

Glutathione S-transferase Pi expression predicts response to adjuvant chemotherapy for stage C colon cancer: a matched historical control study.

BACKGROUND: This study examined the association between overall survival and Glutathione S-transferase Pi (GST Pi) expression and genetic polymorphism in stage C colon cancer patients after resection alone versus resection plus 5-fluourouracil-based adjuvant chemotherapy. METHODS: Patients were drawn from a hospital registry of colorectal cancer resections. Those receiving chemotherapy after it was introduced in 1992 were compared with an age and sex matched control group from the preceding period. GST Pi expression was assessed by immunohistochemistry. Overall survival was analysed by the Kaplan-Meier method and Cox regression. RESULTS: From an initial 104 patients treated with chemotherapy and 104 matched controls, 26 were excluded because of non-informative immunohistochemistry, leaving 95 in the treated group and 87 controls. Survival did not differ significantly among patients with low GST Pi who did or did not receive chemotherapy and those with high GST Pi who received chemotherapy (lowest pair-wise p = 0.11) whereas patients with high GST Pi who did not receive chemotherapy experienced markedly poorer survival than any of the other three groups (all pair-wise p <0.01). This result was unaffected by GST Pi genotype. CONCLUSION: Stage C colon cancer patients with low GST Pi did not benefit from 5-fluourouracil-based adjuvant chemotherapy whereas those with high GST Pi did.

TBL1XR1/TP63: a novel recurrent gene fusion in B-cell non-Hodgkin lymphoma.

Recently, the landscape of single base mutations in diffuse large B-cell lymphoma (DLBCL) was described. Here we report the discovery of a gene fusion between TBL1XR1 and TP63, the only recurrent somatic novel gene fusion identified in our analysis of transcriptome data from 96 DLBCL cases. Based on this cohort and a further 157 DLBCL cases analyzed by FISH, the incidence in de novo germinal center B cell-like (GCB) DLBCL is 5% (6 of 115). The fusion appears exclusive to GCB and was not seen in 138 non-GCB cases examined (P = .008, Fisher exact test) but was present at low incidence in follicular lymphoma (1 of 81). In all 7 cases identified, the 3' end of the fusion consists of exons 4 and onwards of TP63. The recurrence, subtype enrichment, and the remarkably conserved nature of the TP63 portion of the fusion suggest an important functional role in the lymphomas that harbor this event.

Clinicopathological correlates and prognostic significance of glutathione S-transferase Pi expression in 468 patients after potentially curative resection of node-positive colonic cancer.

AIMS: This study investigated the association between glutathione S-transferase Pi (GST Pi) expression, histopathology and overall survival in 468 patients after resection of stage C colonic adenocarcinoma. METHODS AND RESULTS: Data were drawn from a prospective hospital registry of consecutive bowel cancer resections with a minimum follow-up of 5 years. Nuclear and cytoplasmic GST Pi expression, assessed by both intensity of staining and percentage of stained cells at both the central part of the tumour and the invasive tumour front, were evaluated retrospectively by tissue microarray immunohistochemistry on archival specimens. The most effective measure of GST Pi expression was the percentage of immunostained nuclei in central tumour tissue, where >40% stained was associated significantly with high grade, invasion beyond the muscularis propria, involvement of a free serosal surface or apical node, and invasion into an adjacent organ or structure. After adjustment of other predictors, GST Pi expression remained independently prognostic for reduced overall survival (hazard ratio 1.4, P = 0.002). CONCLUSIONS: In patients with clinicopathological stage C colonic cancer, GST Pi expression is associated with features of tumour aggressiveness and with reduced overall survival. Further appropriately designed studies should aim to discover whether GST Pi can predict response to adjuvant chemotherapy.

The histological features of intestinal spirochetosis in a series of 113 patients.

A multicenter retrospective review of cases diagnosed as spirochetosis was performed to determine the presenting symptoms and histological changes. A total of 113 cases were retrieved from the archives, consisting of 97 colorectal specimens and 16 appendices. In only 25 cases was the presenting symptom recorded as diarrhea. Of the colorectal specimens, 87 (90%) showed no mucosal abnormality (apart from the spirochetes); the other 10 showed mucosal inflammation but 6 of them had a diagnosis of another inflammatory disease process accounting for the inflammatory changes. Five appendices showed acute appendicitis; the other 11 were unremarkable. It is concluded that spirochetosis in an unselected general population is unlikely to be of pathological significance. Furthermore, if spirochetosis is observed in an inflamed biopsy, it is most likely to be an incidental finding.