Incorporation of extracorporeal photopheresis into a reduced intensity conditioning regimen in myelodysplastic syndrome and aggressive lymphoma: results from ECOG 1402 and 1902

BACKGROUND

Extracorporeal photopheresis (ECP) is an immunomodulatory cellular therapy which has been shown to induce a tolerogenic state in patients with acute and chronic graft-vs-host disease. ECOG-ACRIN explored the activity of ECP as a part of a reduced intensity conditioning regimen in two multicenter trials in patients with MDS (E1902) and lymphomas (E1402). While both studies closed before completing accrual, we report results in 23 patients (17 MDS and 6 lymphoma).

STUDY DESIGN AND METHODS

Patients received 2 days of ECP followed by pentostatin 4 mg/m2 /day for two consecutive days, followed by 600 cGy of total body irradiation prior to stem cell infusion. Immunosuppression for aGVHD was infusional cyclosporine A or tacrolimus and methotrexate on day +1, +3, with mycophenolate mofetil starting on day 100 for chronic GVHD prophylaxis.

RESULTS

All patients engrafted, with median time to neutrophil and platelet engraftment of 15-18 days and 10-18 days respectively. Grade 3 or 4 aGVHD occurred in 13% and chronic extensive GVHD in 30%.

CONCLUSIONS

These studies demonstrate that ECP/pentostatin/TBI is well tolerated and associated with adequate engraftment of neutrophils and platelets in patients with lymphomas and MDS.

The value of routine bone marrow biopsy in patients with diffuse large B-cell lymphoma staged with PET/CT: a Danish-Canadian study

BACKGROUND

The added diagnostic and prognostic value of routine bone marrow biopsy (BMB) in patients with diffuse large B-cell lymphoma (DLBCL) undergoing positron emission tomography combined with computed tomography (PET/CT) staging is controversial.

PATIENTS AND METHODS

Patients with newly diagnosed DLBCL who underwent both staging PET/CT and BMB were retrospectively identified in British Columbia, Aalborg, and Copenhagen. Original written PET/CT and pathology reports were retrospectively reviewed to determine Ann Arbor stage and outcomes, with and without the contribution of BMB.

RESULTS

A total of 530 patients were identified: 146 (28%) had focal bone marrow (BM) lesions on PET/CT and 87 (16%) had positive BMB. Fifty-two of 146 patients (36%) with positive PET/CT had a positive BMB [39 DLBCL, 13 indolent non-Hodgkin lymphoma (iNHL)], while 35 of 384 patients (9%) with negative PET/CT had positive BMB (12 DLBCL, 23 iNHL). BMB upstaged 12/209 (6%) of stage I/II patients to stage IV, although this was the case for only 3 (1%) patients with DLBCL in the BMB. PET/CT identified BM involvement by BMB with sensitivity 60%, specificity 79%, positive predictive value 36%, and negative predictive value 91%. Concordant histological involvement of the BM by DLBCL was associated with worse overall survival and progression-free survival than discordant or no involvement in univariate and multivariate analyses.

CONCLUSIONS

In patients with DLBCL, staging PET/CT can miss BM involvement with concordant DLBCL (less common) or discordant iNHL (more common). Routine BMB does not add relevant diagnostic or prognostic value over PET/CT alone in the majority of patients with DLBCL.

Outcome of patients with primary refractory diffuse large B cell lymphoma after R-CHOP treatment

Primary refractory diffuse large B cell lymphoma (DLBCL) following R-CHOP chemotherapy is a major concern. We identified 1126 patients with DLBCL treated with R-CHOP from 2000 to 2009, of whom 166 (15 %) had primary refractory disease. Of the 75/166 (45 %) who were age <70 years and had been planned for stage-directed curative therapy, 43 (57 %) were primary nonresponders and 32 (43 %) relapsed within 3 months of completing R-CHOP. Thirty of 75 (40 %) patients had serious comorbidity and organ dysfunction precluding intensive treatment and had palliative treatment only. Twelve of 45 (27 %) patients responded to second-line treatment and underwent ASCT. The median overall survival for the 75 patients was 10 months with only seven patients alive without evidence of disease at follow-up ranging from 14 to 106 months. Primary refractory DLBCL after R-CHOP has a very poor outcome with only anecdotal survivors independent of the intended treatment approach.

IL10 receptor is a novel therapeutic target in DLBCLs

Diffuse large B-cell lymphoma (DLBCL) is a biologically and clinically heterogeneous disease with marked genomic instability and variable response to conventional R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy. More clinically aggressive cases of DLBCLs have high level of circulating interleukin 10 (IL10) cytokine and evidence of activated intracellular STAT3 (signal transducer and activator of transcription 3) signaling. We investigated the role of IL10 and its surface receptor in supporting the neoplastic phenotype of DLBCLs. We determined that IL10RA gene is amplified in 21% and IL10RB gene in 10% of primary DLBCLs. Gene expression of IL10, IL10RA and IL10RB was markedly elevated in DLBCLs. We hypothesized that DLBCLs depend for their proliferation and survival on IL10-STAT3 signaling and that blocking the IL10 receptor (IL10R) would induce cell death. We used anti-IL10R blocking antibody, which resulted in a dose-dependent cell death in all tested activated B-cell-like subtype of DLBCL cell lines and primary DLBCLs. Response of germinal center B-cell-like subtype of DLBCL cell lines to anti-IL10R antibody varied from sensitive to resistant. Cells underwent cell cycle arrest, followed by induction of apoptosis. Cell death depended on inhibition of STAT3 and, to a lesser extent, STAT1 signaling. Anti-IL10R treatment resulted in interruption of IL10-IL10R autostimulatory loop. We thus propose that IL10R is a novel therapeutic target in DLBCLs.

High-resolution chromatin immunoprecipitation (ChIP) sequencing reveals novel binding targets and prognostic role for SOX11 in mantle cell lymphoma

Sex determining region Y-box 11 (SOX11) expression is specific for mantle cell lymphoma (MCL) as compared with other non-Hodgkin's lymphomas. However, the function and direct-binding targets of SOX11 in MCL are largely unknown. We used high-resolution chromatin immunoprecipitation sequencing to identify the direct target genes of SOX11 in a genome-wide, unbiased manner and elucidate its functional significance. Pathway analysis identified WNT, PKA and TGF-beta signaling pathways as significantly enriched by SOX11-target genes. Quantitative chromatin immunoprecipitation sequencing and promoter reporter assays confirmed that SOX11 directly binds to individual genes and modulates their transcription activities in these pathways in MCL. Functional studies using RNA interference demonstrate that SOX11 directly regulates WNT in MCL. We analyzed SOX11 expression in three independent well-annotated tissue microarrays from the University of Wisconsin (UW), Karolinska Institute and British Columbia Cancer Agency. Our findings suggest that high SOX11 expression is associated with improved survival in a subset of MCL patients, particularly those treated with intensive chemotherapy. Transcriptional regulation of WNT and other biological pathways affected by SOX11-target genes may help explain the impact of SOX11 expression on patient outcomes.

The role of body mass index in survival outcome for lymphoma patients: US intergroup experience

BACKGROUND

The role of body mass index (BMI) in survival outcomes is controversial among lymphoma patients. We evaluated the association between BMI at study entry and failure-free survival (FFS) and overall survival (OS) in three phase III clinical trials, among patients with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

A total of 537, 730 and 282 patients with DLBCL, HL and FL were included in the analysis. Baseline patient and clinical characteristics, treatment received and clinical outcomes were compared across BMI categories.

RESULTS

Among patients with DLBCL, HL and FL, the median age was 70, 33 and 56; 29%, 29% and 37% were obese and 38%, 27% and 37% were overweight, respectively. Age was significantly different among BMI groups in all three studies. Higher BMI groups tended to have more favorable prognosis factors at study entry among DLBCL and HL patients. BMI was not associated with clinical outcome with P-values of 0.89, 0.30 and 0.40 for FFS, and 0.64, 0.67 and 0.09 for OS, for patients with DLBCL, HL and FL, respectively. The association remains non-significant after adjusting for other clinical factors in the Cox model. A subset analysis of males with DLBCL treated on R-CHOP revealed no differences in FFS (P = 0.48) or OS (P = 0.58).

CONCLUSION

BMI was not significantly associated with clinical outcomes among patients with DLBCL, HD or FL, in three prospective phase III clinical trials. The findings contradict some previous reports of similar investigations. Further work is required to understand the observed discrepancies.

Reciprocal expression of the endocytic protein HIP1R and its repressor FOXP1 predicts outcome in R-CHOP-treated diffuse large B-cell lymphoma patients

We previously identified autoantibodies to the endocytic-associated protein Huntingtin-interacting protein 1-related (HIP1R) in diffuse large B-cell lymphoma (DLBCL) patients. HIP1R regulates internalization of cell surface receptors via endocytosis, a process relevant to many therapeutic strategies including CD20 targeting with rituximab. In this study, we characterized HIP1R expression patterns, investigated a mechanism of transcriptional regulation and its clinical relevance in DLBCL patients treated with immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone, R-CHOP). HIP1R was preferentially expressed in germinal center B-cell-like DLBCL (P<0.0001) and inversely correlated with the activated B-cell-like DLBCL (ABC-DLBCL) associated transcription factor, Forkhead box P1 (FOXP1). HIP1R was confirmed as a direct FOXP1 target gene in ABC-DLBCL by FOXP1-targeted silencing and chromatin immunoprecipitation. Lower HIP1R protein expression (≤ 10% tumoral positivity) significantly correlated with inferior overall survival (OS, P=0.0003) and progression-free survival (PFS, P=0.0148) in R-CHOP-treated DLBCL patients (n=157). Reciprocal expression with ≥ 70% FOXP1 positivity defined FOXP1(hi)/HIP1R(lo) patients with particularly poor outcome (OS, P=0.0001; PFS, P=0.0016). In an independent R-CHOP-treated DLBCL (n=233) microarray data set, patients with transcript expression in lower quartile HIP1R and FOXP1(hi)/HIP1R(lo) subgroups exhibited worse OS, P=0.0044 and P=0.0004, respectively. HIP1R repression by FOXP1 is strongly associated with poor outcome, thus further understanding of FOXP1-HIP1R and/or endocytic signaling pathways might give rise to novel therapeutic options for DLBCL.

Incidence of transformation to aggressive lymphoma in limited-stage follicular lymphoma treated with radiotherapy

BACKGROUND

The established treatment of limited-stage follicular lymphoma is radiotherapy (RT). There is an inherent risk of transformation of follicular lymphoma to aggressive lymphoma; however, the frequency and impact on the outcome are unknown in limited-stage patients.

MATERIALS AND METHODS

We identified 237 patients with limited-stage follicular lymphoma treated with curative intent RT. Cases were reviewed to determine the frequency of transformation and subsequent survival.

RESULTS

With a median follow-up of 7.4 years, the 10-year risk of transformation was 18.5%. With a median follow-up after transformation of 4.7 years, the 3-year post-transformation progression-free survival (PFS) and overall survival (OS) were 42% and 44%, respectively. The addition of rituximab improved the 3-year post-transformation PFS and OS compared with combination chemotherapy alone (78% versus 15%, P < 0.00001) and (87% versus 38.5%, P < 0.00001), respectively. In multivariate analysis, only rituximab was associated with OS [HR 0.07 (95% CI 0.015-0.312, P = 0.001)] and PFS [HR 0.19 (95% CI 0.55-0.626, P = 0.007)] following transformation.

CONCLUSIONS

There is a moderate risk of transformation in limited-stage follicular lymphoma treated with curative intent RT, and it substantially impacts outcome in these patients. Treatment with rituximab at the time of transformation appears to improve survival in this otherwise poor-risk population.

BCL2 mutations in diffuse large B-cell lymphoma

BCL2 is deregulated in diffuse large B-cell lymphoma (DLBCL) by the t(14;18) translocation, gene amplification and/or nuclear factor-κB signaling. RNA-seq data have recently shown that BCL2 is the most highly mutated gene in germinal center B-cell (GCB) DLBCL. We have sequenced BCL2 in 298 primary DLBCL biopsies, 131 additional non-Hodgkin lymphoma biopsies, 24 DLBCL cell lines and 51 germline DNAs. We found frequent BCL2 mutations in follicular lymphoma (FL) and GCB DLBCL, but low levels of BCL2 mutations in activated B-cell DLBCL, mantle cell lymphoma, small lymphocytic leukemia and peripheral T-cell lymphoma. We found no BCL2 mutations in GC centroblasts. Many mutations were non-synonymous; they were preferentially located in the flexible loop domain, with few in BCL2-homology domains. An elevated transition/transversions ratio supports that the mutations result from somatic hypermutation. BCL2 translocations correlate with, and are likely important in acquisition of, additional BCL2 mutations in GCB DLBCL and FL. DLBCL mutations were not independently associated with survival. Although previous studies of BCL2 mutations in FL have reported mutations to result in pseudo-negative BCL2 protein expression, we find this rare in de-novo DLBCL.

SNP analysis of minimally evolved t(14;18)(q32;q21)-positive follicular lymphomas reveals a common copy-neutral loss of heterozygosity pattern

Follicular lymphoma (FL) cases with a t(14;18)(q32;q21) and minimal or no additional karyotypic alterations, such as copy number gains and losses and/or chromosomal rearrangements, may exhibit pathologic features and a clinical behavior similar to those with more complex karyotypes. This study sought to investigate whether the copy-neutral loss of heterozygosity (cnLOH) profiles of these minimally evolved t(14;18)(q32;q21)-positive follicular lymphoma (MEV-FL) cases are similar to or different from the majority of FL cases with more karyotypic alterations. Affymetrix SNP 6.0 array analysis was applied to the tumor genomes of 23 MEV-FL biopsy samples to assess for the presence of cnLOH. These cases carried either a single or no chromosomal abnormality in addition to t(14;18)(q32;q21) as determined by karyotyping. We found that, although these MEV-FL cases had simple karyotypes, they showed very similar cnLOH profiles as compared to cytogenetically complex cases. The most frequent regions affected by cnLOH were 1p (17%), 6p (17%), 12q (13%) and 16p (13%). Our study suggests that cnLOH alterations may serve as important contributors to the pathological and clinical manifestations of FL.

Stromal gene signatures in large-B-cell lymphomas

BACKGROUND

The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear.

METHODS

We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group.

RESULTS

A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted survival both in patients who received CHOP and patients who received R-CHOP. The prognostically favorable stromal-1 signature reflected extracellular-matrix deposition and histiocytic infiltration. By contrast, the prognostically unfavorable stromal-2 signature reflected tumor blood-vessel density.

CONCLUSIONS

Survival after treatment of diffuse large-B-cell lymphoma is influenced by differences in immune cells, fibrosis, and angiogenesis in the tumor microenvironment.

Impact of whole genome amplification on analysis of copy number variants

Large-scale copy number variants (CNVs) have recently been recognized to play a role in human genome variation and disease. Approaches for analysis of CNVs in small samples such as microdissected tissues can be confounded by limited amounts of material. To facilitate analyses of such samples, whole genome amplification (WGA) techniques were developed. In this study, we explored the impact of Phi29 multiple-strand displacement amplification on detection of CNVs using oligonucleotide arrays. We extracted DNA from fresh frozen lymph node samples and used this for amplification and analysis on the Affymetrix Mapping 500k SNP array platform. We demonstrated that the WGA procedure introduces hundreds of potentially confounding CNV artifacts that can obscure detection of bona fide variants. Our analysis indicates that many artifacts are reproducible, and may correlate with proximity to chromosome ends and GC content. Pair-wise comparison of amplified products considerably reduced the number of apparent artifacts and partially restored the ability to detect real CNVs. Our results suggest WGA material may be appropriate for copy number analysis when amplified samples are compared to similarly amplified samples and that only the CNVs with the greatest significance values detected by such comparisons are likely to be representative of the unamplified samples.

Distinctive patterns of BCL6 molecular alterations and their functional consequences in different subgroups of diffuse large B-cell lymphoma

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed biologically and prognostically distinct subgroups: germinal center B-cell-like (GCB), activated B-cell-like (ABC) and primary mediastinal (PM) DLBCL. The BCL6 gene is often translocated and/or mutated in DLBCL. Therefore, we examined the BCL6 molecular alterations in these DLBCL subgroups, and their impact on BCL6 expression and BCL6 target gene repression. BCL6 translocations at the major breakpoint region (MBR) were detected in 25 (18.8%) of 133 DLBCL cases, with a higher frequency in the PM (33%) and ABC (24%) subgroups than in the GCB (10%) subgroup. Translocations at the alternative breakpoint region (ABR) were detected in five (6.4%) of 78 DLBCL cases, with three cases in ABC and one case each in the GCB and the unclassifiable subgroups. The translocated cases involved IgH and non-IgH partners in about equal frequency and were not associated with different levels of BCL6 mRNA and protein expression. BCL6 mutations were detected in 61% of DLBCL cases, with a significantly higher frequency in the GCB and PM subgroups (>70%) than in the ABC subgroup (44%). Exon-1 mutations were mostly observed in the GCB subgroup. The repression of known BCL6 target genes correlated with the level of BCL6 mRNA and protein expression in GCB and ABC subgroups but not with BCL6 translocation and intronic mutations. No clear inverse correlation between BCL6 expression and p53 expression was observed. Patients with higher BCL6 mRNA or protein expression had a significantly better overall survival. The biological role of BCL6 in translocated cases where repression of known target genes is not demonstrated is intriguing and warrants further investigation.

A comprehensive genetic and histopathologic analysis identifies two subgroups of B-cell malignancies carrying a t(14;19)(q32;q13) or variant BCL3-translocation

The biologic and pathologic features of B-cell malignancies bearing a translocation t(14;19)(q32;q13) leading to a fusion of IGH and BCL3 are still poorly described. Herein we report the results of a comprehensive cytogenetic, fluorescence in situ hybridization (FISH), molecular and histopathological survey of a large series of B-cell malignancies with t(14;19) or variant translocations. A total of 56 B-cell malignancies with a FISH-proven BCL3 involvement were identified with the translocation partners being IGH (n=51), IGL (n=2), IGK (n=2) and a non-IG locus (n=1). Hierarchical clustering of chromosomal changes associated with the t(14;19) indicated the presence of two different groups of IG/BCL3-positive lymphatic neoplasias. The first group included 26 B-cell malignancies of various histologic subtypes containing a relatively high number of chromosomal changes and mostly mutated IgVH genes. This cluster displayed three cytogenetic branches, one with rearrangements in 7q, another with deletions in 17p and a third one with rearrangements in 1q and deletions in 6q and 13q. The second group included 19 cases, mostly diagnosed as B-cell chronic lymphocytic leukemia (B-CLL), and characterized by few additional chromosomal changes (e.g. trisomy 12) and unmutated IgVH genes. In conclusion, our study indicates that BCL3 translocations are not restricted to B-CLL but present in a heterogeneous group of B-cell malignancies.

Primary therapy for adults with T-cell lymphoblastic lymphoma with hematopoietic stem-cell transplantation results in favorable outcomes

BACKGROUND

Controversy exists regarding the role of high-dose therapy followed by stem-cell transplant (SCT) in the treatment of T-cell lymphoblastic lymphoma (T-LBL). We conducted an intention-to-treat analysis of the strategy of SCT as definitive treatment of T-LBL.

PATIENTS AND METHODS

From July 1987 to March 2005, 34 adults with T-LBL were diagnosed and treated in British Columbia. Treatment, before planned SCT, consisted of a non-Hodgkin's lymphoma (NHL)/acute lymphoblastic leukemia hybrid chemotherapy protocol (28 patients) or a standard NHL chemotherapy regimen (six patients).

RESULTS

Median follow-up of the 23 surviving patients is 51 months (range 13-142 months). Twenty-nine proceeded to SCT (four allogeneic, 25 autologous). For all 34 patients, 4-year overall survival (OS) and event-free survival (EFS) are 72% and 68%, respectively. For patients proceeding to SCT, the 4-year OS and EFS are 79% and 73%, respectively. All patients who received allografts are alive without disease at 38-141 months since diagnosis. For patients who received autografts, the 4-year EFS is 69%. Bone marrow involvement was a significant prognostic factor predicting for a worse survival (P = 0.02).

CONCLUSION

A treatment strategy for adults with chemosensitive T-LBL that includes planned consolidation with SCT in first response produces favorable long-term outcome.

A clinicopathological retrospective study of 131 patients with primary bone lymphoma: a population-based study of successively treated cohorts from the British Columbia Cancer Agency

BACKGROUND

Primary bone lymphoma (PBL) is a distinct clinicopathological entity. Although PBL has been reviewed in several small studies, few reflect recent improvements in primary treatment.

METHODS

We used the British Columbia Cancer Agency Lymphoid Cancer Database to identify all patients with PBL (1983-2005). All were staged in a uniform manner and treated with era-specific protocols.

RESULTS

We identified 131 patients with a median age of 63 years (18-87). One third had disease in long bones and another one third had disease in the spine, of which half presented with spinal cord compression. Patients with diffuse large-cell lymphoma (DLCL) (n=103, 79%) had 5- and 10-year overall survivals (OS) of 62% and 41%, respectively. Multivariate analysis identified three prognostic groups: age<60 with International Prognostic Index (IPI) 1-3 (n=43), age>or=60 with IPI 0-3 (n=23) and age>or=60 with IPI 4-5 (n=33), with markedly different 5-year OS of 90%, 61% and 25%, respectively (P<0.0001). Neither primary site nor pathological fracture at presentation had an impact on OS. The 3-year progression-free survival in patients who received rituximab plus combination chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOPR) chemotherapy was 88% compared with 52% in those who received CHOP-like chemotherapy without rituximab (P=0.005). The 10-year OS for those with advanced-stage disease who received irradiation plus chemotherapy was 25% versus 56% for those who received chemotherapy alone (P=0.025). Patients received irradiation if spinal cord compression was present or residual disease at the end of chemotherapy was thought to require it.

CONCLUSIONS

PBL is usually of DLCL type and has an improved outcome with CHOPR. Younger patients with good IPI score have a favorable prognosis.

A phase II study of bortezomib in mantle cell lymphoma: the National Cancer Institute of Canada Clinical Trials Group trial IND.150

BACKGROUND

We evaluated the activity and toxic effects of bortezomib in patients with mantle cell lymphoma.

PATIENTS AND METHODS

Thirty patients, including 29 eligible patients, were enrolled; 13 had received no prior chemotherapy. The dose of bortezomib was 1.3 mg/m2 given on days 1, 4, 8 and 11 every 21 days. Response was assessed according to the International Workshop Criteria for non-Hodgkin's lymphoma and toxicity graded using the National Cancer Institute Common Toxicity Criteria version 2.0.

RESULTS

There were 13 responding patients (46.4%; 95% confidence interval=27.5% to 66.1%), including one unconfirmed complete remission. The median response duration was 10 months. Response rates were similar in previously untreated (46.2%) and treated (46.7%) patients. Neurological toxicity and myalgia led to treatment discontinuation in 10 patients after two to seven treatment cycles. Five serious adverse events (including two deaths) associated with fluid retention were observed in the first 12 patients. We subsequently excluded patients with baseline effusions, dyspnea or edema; no further events were seen.

CONCLUSIONS

Bortezomib is active in treating patients with mantle cell lymphoma. While cumulative neuromuscular toxic effects limited therapy duration and specific issues related to fluid retention require further evaluation, continued study of this drug in combination regimens is warranted.

Favorable outcome of primary mediastinal large B-cell lymphoma in a single institution: the British Columbia experience

BACKGROUND

Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct clinico-pathological subtype of diffuse large B-cell lymphoma (DLBCL). The optimal treatment is unknown, with some studies suggesting a superior outcome with dose-intensive chemotherapy regimens, and the role of radiotherapy remains ill-defined.

PATIENTS AND METHODS

The British Columbia Cancer Agency lymphoma database was searched and records reviewed to identify those patients presenting with a prominent mediastinal mass and considered to be PMBCL based on the current REAL/WHO classifications. Patients were treated based on era-specific BCCA guidelines (1980-1992 MACOPB/VACOPB; 1992-2001 CHOP-type; 2001-present CHOP-R). Beginning in January 1998 involved-field radiotherapy was recommended to be routinely administered following chemotherapy. Prior to this, use of radiotherapy was individualized in advanced disease.

RESULTS

In total, 153 patients with newly diagnosed PMBCL were identified between 28 July 1980 and 30 June 2003. The median age was 37 years (range 13-82) and the majority had stage I/II (74%), bulky mediastinal disease (75%). Overall (OS) and progression-free (PFS) survival at 5 years for the entire cohort were 75% and 69%, respectively. In direct comparison with a cohort of patients with DLBCL (n = 1273), OS (P = 10(-4)) and PFS (P = 0.0001) favored PMBCL. The age-adjusted International Prognostic Index (aaIPI) was not predictive of survival (P = 0.18). Five-year OS in patients < 65 years old treated with MACOPB/VACOPB, CHOP-R and CHOP-type was 87%, 81% and 71% respectively (P = 0.048). In pair-wise survival comparisons, only MACOPB/VACOPB and CHOP-type treated patients were significantly different (P = 0.016). In Cox multiple regression analysis, poor performance status remained the only predictor of survival, with treatment received demonstrating a trend to worse outcome for patients treated with CHOP-type regimens (P = 0.09). In an intention-to-treat analysis comparing the era before radiotherapy was routinely administered with after, there was no significant difference in 5-year PFS (74% versus 62%; P = 0.09) or OS (78% versus 69%; P = 0.14).

CONCLUSIONS

In this single institution, population-based retrospective study, we found that PMBCL patients have excellent survival rates and a distinct plateau is observed in PFS, in striking comparison to DLBCL. The aaIPI was not predictive of survival in this population, suggesting that other prognostic models may be better suited for risk stratification. Dose-intensified chemotherapy with MACOPB or VACOPB demonstrated a trend to superior outcome over CHOP-type chemotherapy. However, further randomized studies are needed and the impact of rituximab on these comparisons must be considered. Finally, the routine addition of radiotherapy does not improve survival.

Expression pattern of intracellular leukocyte-associated proteins in primary mediastinal B cell lymphoma

Two microarray studies of mediastinal B cell lymphoma have shown that this disease has a distinct gene expression profile, and also that this is closest to the pattern seen in classical Hodgkin's disease. We reported previously an immunohistologic study in which the loss of intracellular B cell-associated signaling molecules in Reed-Sternberg cells was demonstrated, and in this study we have investigated the expression of the same components in more than 60 mediastinal B cell lymphomas. We report that these signaling molecules are frequently present, and in particular that Syk, BLNK and PLC-gamma2 (absent from Reed-Sternberg cells) are present in the majority of mediastinal B cell lymphomas. The overall pattern of B cell signaling molecules in this disease is therefore closer to that of diffuse large B cell lymphoma than to Hodgkin's disease, and is consistent with a common cell of origin as an explanation of the similar gene expression profiles.

Concurrent translocation of BCL2 and MYC with a single immunoglobulin locus in high-grade B-cell lymphomas

B-cell leukaemia or lymphoma with a combination of t(8;14)(q24;q32) of Burkitt leukaemia/lymphoma and t(14;18)(q32;q21) of follicular lymphoma may present clinically as de novo acute lymphoblastic leukaemia or transformation of follicular lymphoma to aggressive histology diffuse lymphoma. A number of cell lines have been reported with a complex t(8;14;18) with fusion of MYC, IGH and BCL2 on the same derivative 8 chromosome. The objective of this study was to determine the frequency and chromosomal features of this der(8)t(8;14;18) in a series of acute leukaemias and malignant lymphomas. A database of 1350 leukaemia and lymphoma karyotypes was searched for cases with structural alterations affecting both 8q24 and 18q21. A total of 55 cases were identified, of which eight revealed a complex der(8)t(8;14;18) with an MYC-IGH-BCL2 rearrangement resulting from translocation of BCL2 and MYC with a single disrupted IGH allele. Molecular cytogenetic investigation is essential to identify cases of high-grade leukaemia/lymphoma with concurrent translocations affecting the BCL2 and MYC loci.

Incidence and spectrum of non-Hodgkin lymphoma in Chinese migrants to British Columbia

The incidence and spectrum of non-Hodgkin lymphoma (NHL) differ between the Chinese and Caucasian populations. Using population-based registries, we studied the pattern of NHL in Chinese migrants to British Columbia (BC). The records of all NHL cases of Chinese descent diagnosed between 1980 and 1997 were retrieved. Age-standardized incidences were calculated by 5-year intervals in terms of age and calendar years and the relative rates were compared between the migrant, Hong Kong and BC populations. The histological distribution of NHL was compared with 4500 consecutive NHL cases diagnosed in the two populations. A total of 211 cases of migrant NHL were identified, with an age-standardized incidence rate of 7.11 per 100 000 per year, compared with the Hong Kong and BC rates of 7.91 [standardized incidence ratio (SIR) = 0.86, P = 0.01] and 11.88 (SIR = 0.56, P < 0.01). The standardized rates of follicular lymphoma remained low, but the incidence of gastric and nasal natural killer/T lymphomas in migrants were lower than expected. Genetic factors appeared to be stronger than environmental factors in governing the overall incidence of NHL in Chinese. However, certain subtypes of lymphoma may show decreased rates in migrants because of environmental factors.

Aggressive B-cell lymphomas: a review based on the workshop of the XI Meeting of the European Association for Haematopathology

The generic term aggressive B-cell lymphoma includes a variety of entities, each with particular diagnostic and therapeutic issues. To define these entities better and to help confront such issues, a workshop was organized by the European Association of Haematopathology (EAHP) and the Society of Haematology during the XI Meeting of the EAHP, held in Italy in May 2002. Participants were asked to submit cases under various categories and all cases submitted were examined and reviewed by the panel members. The panel's diagnoses formed the basis for discussion at the workshop and a limited number of cases were selected to be presented in more detail and discussed during the workshop. After the workshop the panel met again to discuss the outcome, summarized in this report, which describes the panel's proposals regarding diagnostic criteria, terminology, the definition of new entities and evaluation of biological differential and new prognostic parameters.

Characterization of peripheral T-cell lymphomas in a single North American institution by the WHO classification

BACKGROUND

All peripheral T-cell lymphomas (PTCLs) diagnosed at a single institution were evaluated to determine the unique clinical features and outcome of specific entities and test the predictive validity of the International Prognostic Index (IPI).

PATIENTS AND METHODS

Cases of PTCL seen at the British Columbia Cancer Agency between 1981 and 2000 were identified. Pathologic material was re-assessed and classified according to the WHO classification, and patients were staged and treated uniformly according to era-specific guidelines. In total, there were 199 patients with PTCL and the most common subtypes were peripheral T-cell lymphoma unspecified (PTCL-US) (59%), anaplastic large-cell lymphoma, systemic type (ALCL) (17%) and extranodal NK/T-cell lymphoma, nasal and nasal-type (NASAL) (9%). Most patients were treated with CHOP-type chemotherapy.

RESULTS

Three distinct prognostic subgroups were notable on survival analysis: favorable (cutaneous ALCL), 5-year overall survival (OS) 78%; intermediate [PTCL, ALCL and angioimmunoblastic lymphoma (AILT)], 5-year OS 35-43%; unfavorable [NASAL and enteropathy-type T-cell lymphoma (ETTL)], 5-year OS 22-24%. Furthermore, in PTCL-US and ALCL clinical separation of patients into good risk (IPI 0,1) and poor risk (IPI > or =2) subsets was demonstrated.

CONCLUSIONS

A large proportion of PTCL patients have poor risk disease and/or a histologically aggressive subtype with frequent relapse and unfavorable outcome. For these patients, treatment with CHOP chemotherapy is only minimally effective and new strategies need to be developed, an effort that will require a multi-institution international collaboration due to the rarity of most subtypes.

Establishment of a novel anaplastic large-cell lymphoma-cell line (COST) from a ‘small-cell variant’ of ALCL

Anaplastic large-cell lymphoma (ALCL) is a distinct biological and cytogenetic entity with a broad spectrum of morphological features (common type, small-cell variant and lymphohistiocytic variant). Few cell lines of ALCL are available and they all originate from primary tumors demonstrating the common type morphology (ie large-sized lymphoma cells). We established a new ALCL cell line (COST) from the peripheral blood of a patient with a small-cell variant of ALCL, at diagnosis. Cells growing in vitro and in SCID mice consisted of two populations, that is, small- and large-sized cells as seen in the patient's tumor. Both large and small malignant cells were positive for CD43/MT1 T-cell associated antigen, perforin, granzyme B and TIA-1, but negative for CD2, CD3, CD5, CD7, CD4 and CD8 antigens. Standard cytogenetic studies as well as multiplex FISH confirmed the presence of the canonical t(2;5)(p23;q35) translocation, but also revealed additional numerical and structural abnormalities. The COST cell line is the first ALCL small-cell variant cell line, and thus provides a potentially useful tool for further functional and molecular studies that should improve our understanding of the small-cell variant of ALCL, which is more frequently complicated by a leukemic phase.

Hodgkin’s lymphoma in Chinese migrants to British Columbia:a 25-year survey

BACKGROUND

Compared with the West, Hodgkin's lymphoma in Oriental countries is characterized by a lower incidence rate and a higher proportion of mixed cellularity histology. Both environmental and genetic factors may be involved.

PATIENTS AND METHODS

The incidence and pattern of pathology of Hodgkin's lymphoma in the migrant Chinese population (0.4 million) in British Columbia (population 3.2 million) were studied. From a computerized database, all Hodgkin's lymphoma cases diagnosed in British Columbia from 1970 to 1997 were identified. Chinese descent was determined using patient surname by standard methodology and verified from the treatment record or by patient interview. The corresponding figures from the Chinese population in Hong Kong were used for comparison. For incidence rates, the age-specific incidence of Hodgkin's lymphoma in Hong Kong was obtained from the government cancer registry. For comparison of histology subtypes, 200 Hodgkin's lymphoma records from a Hong Kong regional referral center for the same time period were reviewed. Crude and age-standardized incidence rates were calculated by 5-year intervals in terms of age and calendar year, and relative rates were compared between the three populations.

RESULTS

From 1970 to 1997, Hodgkin's lymphoma was diagnosed in 34 Chinese patients in BC, with 24 cases diagnosed from 1970 to 1994. Thus, the crude and age-adjusted incidence rates from 1970 to 1994 were 0.91 and 1.14 per 100,000 per year in the British Columbia Chinese migrant population. Within the same period, 1862 cases of Hodgkin's lymphoma were diagnosed in British Columbia, giving a provincial background crude and age-adjusted incidence rates of 5.2 and 4.87 per 100,000 per year. The number of cases in the Hong Kong Chinese population (1970-1994) was 404, giving crude and age-adjusted incidence rates of 0.32 and 0.31 per 100,000 per year, respectively. Corrected for age and calendar year trends, the observed 25-year incidence of Hodgkin's lymphoma in British Columbia Chinese was significantly lower than expected from the British Columbia background population [24 observed versus 71 expected cases; standardized incidence ratio (SIR) = 0.34; 90% confidence interval (CI) 0.24-0.48; P <0.0001]. On the other hand, it is higher than that expected by extrapolating from the Hong Kong Chinese population (24 observed versus 8.5 expected cases; SIR = 2.81; 90% CI 1.94-3.95; P <0.0001). The difference is mainly accounted for by young patients with nodular sclerosis type disease in the migrant population.

CONCLUSIONS

Although any conclusion about the impact of migration on Hodgkin's lymphoma incidence and types in the Chinese population must be considered tentative due to the small number of observed cases and confounding variables such as age, changing diagnostic standards and secular trends in Hodgkin's lymphoma rates, our data demonstrate a tendency for the Chinese population of British Columbia to take on a Western pattern of Hodgkin's lymphoma. This observation provides additional evidence that both genetic and environmental influences play a role in the pathogenesis of this lymphoma, and that environmental factors can exert their influence over a relatively short period of time.

Limited-stage mantle-cell lymphoma

BACKGROUND

Mantle-cell lymphoma (MCL) is known to have a poor outcome, however, most patients present with advanced-stage disease. Little information is available on limited-stage MCL.

PATIENTS AND METHODS

We retrospectively reviewed clinicopathological information on all patients with limited-stage MCL seen at the British Columbia Cancer Agency since 1984.

RESULTS

Twenty-six patients had low bulk (<10 cm) stage IA (12 patients) or IIA (14 patients) MCL. Initial therapy was involved-field radiation therapy (RT) with or without chemotherapy (CT), 17 patients; CT alone or observation, nine patients. Fifteen patients are alive at a median follow-up of 72 months (range 14-194). Progression-free survival (PFS) at 2 and 5 years was 65% and 46%, and overall survival (OS) 86% and 70%, respectively. Five patients surviving beyond 8 years. Only age and initial use of RT significantly affected PFS. Five-year PFS for patients <60 years of age was 83%, compared with 39% for those aged >/= 60 years, P = 0.04. Patients receiving RT with or without CT (n = 17), had a 5-year PFS of 68%, compared with 11% for those not receiving RT (n = 9, P = 0.002). Receiving RT eliminated the impact of age on PFS (with RT the 5-year PFS was 83% for those aged <60 years and 57% for those >/= 60 years, P = 0.17). Although OS for the whole group was 53% at 6 years, it was 71% for those initially treated with RT, but only 25% for those not given RT (P = 0.13).

CONCLUSION

In our experience, patients with limited-stage MCL had an improved PFS when treated with regimens including RT, with a trend towards improved OS. These results suggest a potentially important role for RT in limited-stage MCL.

Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases

Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.

Bcl-3/IgH translocation (14;19)(q32;q13) in non-Hodgkin's lymphomas

The recurrent cytogenetic (CG) abnormality t(14;19)(q32;q13) involving the oncogene BCL3 is described in patients with atypical chronic lymphocytic leukemia (CLL). We report four patients with non-Hodgkin's lymphoma (NHL) bearing t(14;19). All cases were female and their age ranged from 62 to 91. Histologically, there were two cases of small lymphocytic lymphoma (SLL), both CD11c positive with atypical morphology, one case of Burkitt like lymphoma (BLL), and one case of diffuse large cell lymphoma (DLC-L). One SLL patient showed t(14;19) as the sole abnormality and experienced a benign course for 8 years. The other three cases showed secondary CG progression, including tetraploidy, del(6q), t(8;22) and del(13q). These cases were aggressive in clinical behavior, including an SLL case which transformed to DLC lymphoma in 4 months. Southern analysis and long distance PCR confirmed BCL3/IgH Calpha translocation in one case. We propose that NHLs with t(14;19) may have evolved from the same spectrum of disease as atypical CLL. The poor prognosis of t(14;19) disease is associated with the occurrence of recurrent secondary CG changes, commonly found in B cell lymphoproliferative diseases.

Heavy multinodular cutaneous lymphoid infiltrates: clinicopathologic features and B-cell clonality

BACKGROUND

Criteria for distinguishing between cutaneous lymphoid hyperplasia (CLH) and low-grade B-cell lymphoma are not well defined. We examined the hypothesis that the presence of a clonal B-cell population in heavy multinodular lymphoid infiltrates correlates with clinical presentation and outcome.

METHODS

We identified 29 patients with skin lesions characterized histologically by a heavy dermal lymphocytic infiltrate with a multinodular architecture and extension into deep dermis and subcutaneous fat. Clonality was assessed immunophenotypically by light-chain restriction and also by analysis for IgH-gene rearrangement using PCR on DNA extracted from paraffin blocks.

RESULTS

Follow-up (mean 80 months; median 45 months) was obtained in all patients. Twenty-four patients (83%) presented with a solitary lesion: only four had solitary recurrences, and none developed multiple synchronous lesions or systemic B-cell lymphoma. However, 9/24 of these solitary lesions (38%) were clonal by light-chain restriction or IgH PCR; 5/29 patients (17%) presented with multiple recurrent lesions and continued to develop lesions during the period of follow-up; 3/5 patients (60%) with multiple lesions demonstrated a B-cell clone. No patient developed systemic B-cell lymphoma.

CONCLUSIONS

Heavy, multinodular cutaneous lymphoid infiltrates have an excellent prognosis. Multiple lesions at presentation are the best predictor of recurrent multiple lesions confined to the skin. The presence of a clonal B-cell population does not correlate with clinical presentation or histology, nor does it predict development of further lesions or systemic lymphoma.

Primary cutaneous follicular lymphoma: an assessment of clinical, histopathologic, immunophenotypic, and molecular features

PURPOSE

Unlike nodal follicular lymphoma (NFL), Primary cutaneous follicular lymphomas (PCFLs) rarely express Bcl-2 protein or t(14;18)(q32;q21) (Bcl-2/IgH). The aim of this study was to further characterize PCFL in a large series from North America.

PATIENTS AND METHODS

Clinical data and archival formalin-fixed, paraffin-embedded tissue were obtained from 32 patients. PCFL was defined as follicular lymphoma limited to the skin at the time of diagnosis and within the first 6 months after diagnosis. Specimens were analyzed for the expression of CD3, CD10, CD20, Bcl-2, and Bcl-6 proteins by immunohistochemistry as well as for the presence of t(14;18)(q32;q21) by polymerase chain reaction.

RESULTS

The male-to-female ratio was 1.5:1, with a median age of 60 years. Twenty-four patients had lesions on the head and neck, five had lesions on the trunk, and three had lesions on both head and trunk. Follow-up data were available in all cases, with a mean length of 35.8 months. The majority of the patients were treated with radiation therapy. All patients were alive at last follow-up except one. Recurrence was noted in seven patients (22%), after a mean disease-free survival time of 17.7 months. CD10 and Bcl-6 expression were seen in 29 (91%) of 32 and 31 (97%) of 32 cases, respectively. Bcl-2 expression was noted in 13 (41%) of 32 cases. PCR results for t(14;18)(q32;q21) were positive in 11 (34%) of 32 patients and showed correlation with Bcl-2 protein expression. The sequencing of the t(14;18)(q32;q21) amplicons confirmed unique breakpoints in each of the seven tested cases. Comparison between the Bcl-2 and/or t(14;18)(q32;q21)-positive and t(14;18)(q32;q21)-negative cases revealed no significant difference in age, site, clinical course, or outcome.

CONCLUSION

We demonstrated Bcl-2 protein expression and t(14;18)(q32;q21) in a significant minority of cases, suggesting a relationship with NFL. It remains to be seen whether, on longer follow-up, there is any clinical difference in cases with and without t(14;18)(q32;q21).

Establishment and comprehensive analysis of a new human transformed follicular lymphoma B cell line, Tat-1

A spontaneously EBV transformed follicular lymphoma (FL) cell line, Tat-1, was established from the lymph node biopsy specimen of a patient with B cell FL, grade 1 in transformation to high grade disease. Tat-1 cells expressed lymphoid markers and developed tumor masses in immunodeficient mice. Bcl-2, Bcl-X(L), Bax and p53 protein expression was revealed by Western blotting. Flow cytometric analysis confirmed P-gp expression. Cytogenetically, the Tat-1 cell line showed identical chromosomal alterations to that of the initial biopsy specimen, among which the most notable were the t(14;18) typical of FL and additional abnormalities involving chromosomes 1, 8 and 13. Multicolor FISH analysis delineated all abnormalities, including a t(1p;8q), a der(8)(8q24::14q32::18q21) and a der(13)(13q32::8q24::14q32::18q21). Further FISH investigations using a locus-specific probe cocktail containing c-myc, IgH and bcl-2 revealed fusion of these three loci on the derivatives 8 and 13, in addition to the derivative 14 IgH/bcl-2 fusion and an extra copy of c-myc on derivative chromosome 1. These results demonstrate an additional example of the deregulation of bcl-2 and c-myc expression through recombination with a single IgH enhancer region. The unusual molecular features of the Tat-1 cell line render it a unique tool for studies focused on cytogenetic alterations, expression of multidrug resistance phenotype and expression of anti-apoptotic proteins in FL.

Cyclin D3 is a target gene of t(6;14)(p21.1;q32.3) of mature B-cell malignancies

Chromosomal translocation t(6;14)(p21.1;q32.3) has been reported as a rare but recurrent event not only in myeloma and plasma cell leukemia but also in diffuse large B-cell non-Hodgkin lymphoma (B-NHL) (diffuse large B-cell lymphoma [DLBCL]) and splenic lymphoma with villous lymphocytes (SLVL); however, the nature of the target gene(s) has not been determined. This study identified t(6;14)(p21.1;q32.3) in 3 cases of transformed extranodal marginal zone B-NHL, in 1 case of SLVL, and in 1 case of a low-grade B-cell lymphoproliferative disorder. In a sixth case, a CD5(+) DLBCL, the translocation was identified by molecular cloning in the absence of cytogenetically detectable change. Two chromosomal translocation breakpoints were cloned by using long-distance inverse polymerase chain reaction methods. Comparison with the genomic sequence for chromosome 6p21.1 showed breakpoints approximately 59 and 73.5 kilobases 5' of the cyclin D3 (CCND3) gene with no other identifiable transcribed sequences in the intervening region. Although Southern blotting with derived genomic 6p21.1 probes failed to detect other rearrangements, fluorescent in situ hybridization assays, using BAC (bacterial artificial chromosome) clones spanning and flanking the CCND3 locus, along with probes for IGH confirmed localization of 6p21.1 breakpoints within the same region, as well as fusion of the CCND3 and IGH loci. Furthermore, in all cases, high-level expression of CCND3 was demonstrated at RNA and/or protein levels by Northern and Western blotting and by immunohistochemistry. These data implicate CCND3 as a dominant oncogene in the pathogenesis and transformation in several histologic subtypes of mature B-cell malignancies with t(6;14)(p21.1;q32.3) and suggest that CCND3 overexpression seen in about 10% of DLBCL cases may have a genetic basis.

Systemic anaplastic large-cell lymphoma: results from the non-Hodgkin's lymphoma classification project

Anaplastic large-cell lymphoma (ALCL) is a heterogeneous process that may have a T-cell, B-cell, or indeterminant (null) phenotype and which may or may not express the anaplastic lymphoma kinase (ALK) oncoprotein. Because the clinical significance of these variants of ALCL is unclear, we evaluated the cases of ALCL-T/null and ALCL-B identified in the Non-Hodgkin's Lymphoma Classification Project. We evaluated 1,378 cases of non-Hodgkin's lymphoma (NHL), and a consensus diagnosis of ALCL-T/null was made in 33 patients (2.4%) with a diagnostic accuracy of 85%. Compared to 96 patients with other forms of peripheral T-cell lymphoma (PTCL), those with ALCL-T/null were significantly younger, less likely to have advanced-stage disease or bone marrow involvement, more likely to have a low International Prognostic Index score, and had a significantly better survival. Among those with ALCL-T/null, there were no significant differences in the clinical features or survival on the basis of ALK expression. A consensus diagnosis of ALCL-B was made in 15 patients (1.1%), and the diagnostic accuracy was 67%. However, compared to 366 patients with other forms of diffuse large B-cell lymphoma (DLBCL), those with ALCL-B were no different with regard to clinical features or survival. We conclude that patients with ALCL-T/null have favorable prognostic features and excellent survival and should be separated from those with other forms of PTCL for prognostic and therapeutic purposes. In contrast, patients with ALCL-B appear to be similar to those with other forms of DLBCL.

MCL1 transgenic mice exhibit a high incidence of B-cell lymphoma manifested as a spectrum of histologic subtypes

Viability-promoting genes such as BCL2 play an important role in human cancer but do not directly cause aggressive tumors. BCL2 transgenic mice develop lymphoma at low frequency, hindering studies of tumorigenesis and its inhibition in the presence of such gene products. MCL1 is a member of the BCL2 family that is highly regulated endogenously and that promotes cell viability and immortalization when introduced exogenously. Mice expressing an MCL1 transgene in hematolymphoid tissues have now been monitored for an extended period and were found to develop lymphoma with long latency and at high probability (more than 85% over 2 years). In most cases, the disease was widely disseminated and of clonal B-cell origin. A variety of histologic subtypes were seen, prominently follicular lymphoma and diffuse large-cell lymphoma. MCL1 thus sets the stage for the development of lymphoma as does BCL2, disease occurring with high probability and recapitulating a spectrum of subtypes as seen in human patients. These findings with the transgene underscore the importance of the normal, highly regulated pattern of MCL1 expression, in addition to providing a model for studying tumorigenesis and its inhibition in the presence of a viability promoting BCL2 family member. (Blood. 2001;97:3902-3909)

Analysis of secondary chromosomal alterations in 165 cases of follicular lymphoma with t(14;18)

Follicular lymphoma is characterized by the t(14;18) in up to 85% of cases. Almost all cases display evidence of secondary chromosomal alterations at initial diagnosis. The influence of recurrent secondary changes on disease progression has not been fully determined. The purpose of this study was to define the full spectrum of recurrent karyotypic events present at diagnosis in a large cohort of cases and to evaluate the sequence of cytogenetic evolution in relation to morphologic progression. A total of 165 cases of follicular lymphoma with t(14;18) were ascertained for which complete clinical information, histopathology, immunophenotype, and karyotype were available. One hundred sixty cases showed secondary alterations with an average of 7.9 additional changes per case. Recurrent alterations seen at the 10% or greater level included +X, +1q21-q44, +7, +12q, +18q, del(1)(p36), del(6q), del(10)(q22-q24), the development of polyploidy and sidelines, and the presence of extra marker chromosomes and chromosomal additions. Changes that correlated with morphologic progression included del(1)(p36), del(6q), del(10)(q22-q24), +7, the total number of abnormalities, the number of markers and additions, and the presence of polyploidy. The most frequent second event arising after the t(14;18) was duplication of the der(18)t(14;18). This study demonstrates that the number and type of secondary chromosomal alterations in follicular lymphoma is highly variable between cases, but that a relatively small number of changes are seen repeatedly in different combinations. A consistent pattern of cytogenetic evolution could not be identified. Potentially significant gene duplications or amplifications may be disguised within marker chromosomes and additions. Additional cytogenetic investigation is required to decipher the karyotypic complexity associated with the progression of follicular lymphoma.

Interleukin 13 and interleukin 13 receptor are frequently expressed by Hodgkin and Reed-Sternberg cells of Hodgkin lymphoma

Hodgkin lymphoma (HL) is characterized by the abnormal expression of multiple cytokines, accounting for its unique clinicopathologic features. We have previously shown that interleukin-13 (IL-13) is secreted by HL cell lines and may serve as an autocrine growth factor. To determine the frequency of IL-13 expression in lymphoma patients, tissue sections from 36 patients with classical HL, 5 patients with nodular lymphocyte predominance HL (NLPHL), and 23 patients with non-Hodgkin lymphoma (NHL) were subjected to in situ hybridization. In 31 of 36 cases (86%) of classical HL patients of all histologic subtypes, between 25% to almost 100% of Hodgkin and Reed Sternberg (HRS) cells were positive for IL-13 expression. In contrast, in no case of NLPHL and in only 4 of 23 NHL cases (1 of 5 T-cell-rich B-cell lymphomas, 2 of 5 anaplastic large cell lymphomas, and 1 of 5 peripheral T-cell lymphomas) did the neoplastic cells express IL-13. The expression of the IL-13 receptor chain alpha1 (IL-13Ralpha1) was also analyzed by in situ hybridization. In 24 of 27 (89%) cases of classical HL, between 25% to 75% of HRS cells, as well as a high frequency of lymphocytes and histiocytes, were positive for IL-13Ralpha1 expression. These results were confirmed by the construction of complementary DNA libraries from single HRS cells, followed by polymerase chain reaction analysis, in which IL-13Ralpha1 transcripts were found to be present in all 6 cases of HL. These data indicate that expression of IL-13 and IL-13Ralpha1 is a common feature of HRS cells in HL, consistent with the hypothesis that IL-13 may play a role in autocrine growth in classical HL.