Background: Large B-cell lymphoma (LBCL) is the most common lymphoma and is known to be a biologically heterogeneous disease regarding genetic, phenotypic, and clinical features. Although the prognosis is good, one-third has a primary refractory or relapsing disease which underscores the importance of developing predictive biological markers capable of identifying high- and low-risk patients. DNA methylation (DNAm) and telomere maintenance alterations are hallmarks of cancer and aging. Both these alterations may contribute to the heterogeneity of the disease, and potentially influence the prognosis of LBCL.
Results: We studied the DNAm profiles (Infinium MethylationEPIC BeadChip) and relative telomere lengths (RTL) with qPCR of 93 LBCL cases: Diffuse large B-cell lymphoma not otherwise specified (DLBCL, n = 66), High-grade B-cell lymphoma (n = 7), Primary CNS lymphoma (n = 8), and transformation of indolent B-cell lymphoma (n = 12). There was a substantial methylation heterogeneity in DLBCL and other LBCL entities compared to normal cells and other B-cell neoplasms. LBCL cases had a particularly aberrant semimethylated pattern (0.15 ≤ β ≤ 0.8) with large intertumor variation and overall low hypermethylation (β > 0.8). DNAm patterns could not be used to distinguish between germinal center B-cell-like (GC) and non-GC DLBCL cases. In cases treated with R-CHOP-like regimens, a high percentage of global hypomethylation (β < 0.15) was in multivariable analysis associated with worse disease-specific survival (DSS) (HR 6.920, 95% CI 1.499–31.943) and progression-free survival (PFS) (HR 4.923, 95% CI 1.286–18.849) in DLBCL and with worse DSS (HR 5.147, 95% CI 1.239–21.388) in LBCL. These cases with a high percentage of global hypomethylation also had a higher degree of CpG island methylation, including islands in promoter-associated regions, than the cases with less hypomethylation. Additionally, telomere length was heterogenous in LBCL, with a subset of the DLBCL-GC cases accounting for the longest RTL. Short RTL was independently associated with worse DSS (HR 6.011, 95% CI 1.319–27.397) and PFS (HR 4.689, 95% CI 1.102–19.963) in LBCL treated with R-CHOP-like regimens.
Conclusion: We hypothesize that subclones with high global hypomethylation and hypermethylated CpG islands could have advantages in tumor progression, e.g. by inactivating tumor suppressor genes or promoting treatment resistance. Our findings suggest that cases with high global hypomethylation and thus poor prognosis could be candidates for alternative treatment regimens including hypomethylating drugs.
Background: Hodgkin lymphoma (HL) patients have a good prognosis after adequate treatment. Previous treatment with mantle field irradiation has been accompanied by an increased long-term risk of cardiovascular disease (CVD). This study identified co-morbidity factors for the development of cardiovascular side effects and initiated an intervention study aimed to decrease morbidity and mortality of CVD in HL survivors.
Design: Hodgkin lymphoma patients aged ≤45 years diagnosed between 1965 and 1995 were invited to participate. In total, 453 patients completed a questionnaire that addressed co-morbidity factors and clinical symptoms. Of these, 319 accepted to participate in a structured clinical visit. The statistical analyses compared individuals with CVD with those with no CVD.
Results: Cardiovascular disease was reported by 27.9%. Radiotherapy (odds ratio [OR]: 3.27), hypertension and hypercholesterolemia were shown to be independent risk factors for the development of CVD. The OR for CVD and valve disease in patients who received radiotherapy towards mediastinum was 4.48 and 6.07, respectively. At clinical visits, 42% of the patients were referred for further investigation and 24% of these had a cardiac ultrasound performed due to previously unknown heart murmurs.
Conclusion: Radiotherapy towards mediastinum was an independent risk factor for CVD as well as hypercholesterolemia and hypertension. A reasonable approach as intervention for this cohort of patients is regular monitoring of hypertension and hypercholesterolemia and referral to adequate investigation when cardiac symptoms appear. Broad knowledge about the side effects from radiotherapy in the medical community and well-structured information regarding late side effects to the patients are all reasonable approaches as late effects can occur even 40 years after cancer treatment.
The tumor cells in diffuse large B-cell lymphomas (DLBCL) are considered to originate from germinal center derived B-cells (GCB) or activated B-cells (ABC). Gene expression profiling (GEP) is preferably used to determine the cell of origin (COO). However, GEP is not widely applied in clinical practice and consequently, several algorithms based on immunohistochemistry (IHC) have been developed. Our aim was to evaluate the concordance of COO assignment between the Lymph2Cx GEP assay and the IHC-based Hans algorithm, to decide which model is the best survival predictor. Both GEP and IHC were performed in 359 homogenously treated Swedish and Danish DLBCL patients, in a retrospective multicenter cohort. The overall concordance between GEP and IHC algorithm was 72%; GEP classified 85% of cases assigned as GCB by IHC, as GCB, while 58% classified as non-GCB by IHC, were categorized as ABC by GEP. There were significant survival differences (overall survival and progression-free survival) if cases were classified by GEP, whereas if cases were categorized by IHC only progression-free survival differed significantly. Importantly, patients assigned as non-GCB/ABC both by IHC and GEP had the worst prognosis, which was also significant in multivariate analyses. Double expression of MYC and BCL2 was more common in ABC cases and was associated with a dismal outcome. In conclusion, to determine COO both by IHC and GEP is the strongest outcome predictor to identify DLBCL patients with the worst outcome.
Despite having common overlapping immunophenotypic and morphological features, T-cell lymphoblastic leukemia (T-ALL) and lymphoma (T-LBL) have distinct clinical manifestations, which may represent separate diseases. We investigated and compared the epigenetic and genetic landscape of adult and pediatric T-ALL (n = 77) and T-LBL (n = 15) patient samples by high-resolution genome-wide DNA methylation and Copy Number Variation (CNV) BeadChip arrays. DNA methylation profiling identified the presence of CpG island methylator phenotype (CIMP) subgroups within both pediatric and adult T-LBL and T-ALL. An epigenetic signature of 128 differentially methylated CpG sites was identified, that clustered T-LBL and T-ALL separately. The most significant differentially methylated gene loci included the SGCE/PEG10 shared promoter region, previously implicated in lymphoid malignancies. CNV analysis confirmed overlapping recurrent aberrations between T-ALL and T-LBL, including 9p21.3 (CDKN2A/CDKN2B) deletions. A significantly higher frequency of chromosome 13q14.2 deletions was identified in T-LBL samples (36% in T-LBL vs. 0% in T-ALL). This deletion, encompassing the RB1, MIR15A and MIR16-1 gene loci, has been reported as a recurrent deletion in B-cell malignancies. Our study reveals epigenetic and genetic markers that can distinguish between T-LBL and T-ALL, and deepen the understanding of the biology underlying the diverse disease localization.
When treating limited stage classical Hodgkin lymphoma (cHL), balancing treatment efficacy and toxicity is important. Toxicities after extended-field radiotherapy are well documented. Investigators have aimed at reducing toxicity without compromising efficacy, mainly by using combined modality treatment (CMT), i.e. chemotherapy and limited-field radiotherapy. In some clinical trials, radiotherapy has been omitted. We evaluated 364 patients with stage I-IIA cHL treated between 1999 and 2005. Patients were treated with two or four cycles of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) according to presence of risk factors, followed by 30 Gy limited-field (reduced compared to involved-field) radiotherapy. After a median follow-up of 16 years for survival, freedom from progression at five and ten years was 93% and overall survival at 5 and 10 years was 98% and 96%, respectively. Only two relapses, out of 27, occurred after more than 5 years. There was no excess mortality compared to the general population. Of the analysed subgroups, only patients with progression within five years showed significant excess mortality. The absence of excess mortality questions the concept of omitting radiotherapy after short-term chemotherapy, a strategy that has been associated with an elevated risk of relapse but not yet with a proven reduced long-term excess mortality.
We recently reported a truncating deletion in the NFKBIE gene, which encodes IkB epsilon, a negative feedback regulator of NF-kB, in clinically aggressive chronic lymphocytic leukemia (CLL). Because preliminary data indicate enrichment of NFKBIE aberrations in other lymphoid malignancies, we screened a large patient cohort (n = 1460) diagnosed with different lymphoid neoplasms. While NFKBIE deletions were infrequent in follicular lymphoma, splenic marginal zone lymphoma, and T-cell acute lymphoblastic leukemia (< 2%), slightly higher frequencies were seen in diffuse large B- cell lymphoma, mantle cell lymphoma, and primary central nervous system lymphoma (3% to 4%). In contrast, a remarkably high frequency of NFKBIE aberrations (46/203 cases [22.7%]) was observed in primary mediastinal B-cell lymphoma (PMBL) and Hodgkin lymphoma (3/11 cases [27.3%]). NFKBIE-deleted PMBL patients were more often therapy refractory (P =.022) and displayed inferior outcome compared with wild- type patients (5-year survival, 59% vs 78%; P = .034); however, they appeared to benefit from radiotherapy P = .022) and rituximab-containing regimens (P = .074). NFKBIE aberrations remained an independent factor in multivariate analysis (P =.003) and when restricting the analysis to immunochemotherapy-treated patients (P = .008). Whole-exome sequencing and gene expression profiling verified the importance of NF-kB deregulation in PMBL. In summary, we identify NFKBIE aberrations as a common genetic event across B-cell malignancies and highlight NFKBIE deletions as a novel poor-prognostic marker in PMBL.
Supplement: 5, Meeting Abstract: P091
Treatment for follicular lymphoma (FL) improved with rituximab. In Sweden, first-line rituximab was gradually introduced between 2003 and 2007, with regional differences. The first national guidelines for FL were published in November 2007, recommending rituximab in first-line therapy. Using the population-based Swedish Lymphoma Registry, 2641 patients diagnosed with FL from 2000 to 2010 were identified and characterized by year and region of diagnosis, age (median, 65 years), gender (50% men), first-line therapy and clinical risk factors. Overall and relative survivals were estimated by calendar periods (2000-2002, 2003-2007 and 2008-2010) and region of diagnosis. With each period, first-line rituximab use and survival increased. Survival was superior in regions where rituximab was quickly adopted and inferior where slowly adopted. These differences were independent in multivariable analyses. Ten-year relative survival for patients diagnosed 2003-2010 was 92%, 83%, 78% and 64% in the age groups 18-49, 50-59, 60-69 and. 70, respectively. With increasing rituximab use, male sex emerged as an adverse factor. Survival improved in all patient categories, particularly in elderly women. The introduction and the establishment of rituximab have led to a nationwide improvement in FL survival. However, rituximab might be inadequately dosed in younger women and men of all ages.