Habermann, Thomas M.

Abstract Background. Several recent studies have reported an inverse relationship between sun exposure and non-Hodgkin (NHL) risk. One hypothesis is that vitamin D mediates this effect. We evaluated the association of sun exposure at various ages and common variants in vitamin D related genes with risk of NHL and its major subtypes. Methods. Newly diagnosed NHL cases (N=1023) and frequency matched controls (N=1254) were enrolled in a clinic-based case-control study conducted at the Mayo Clinic. Thirty-eight single nucleotide polymorphisms (SNPs) from 5 candidate genes relevant to vitamin D metabolism and sun sensitivity (IRF4, RXR, VDR, CYP24A1, CYP27B1) were genotyped. Participants also completed a detailed questionnaire, including self-reported sun exposure at ages 13-21, 22-40, and 41+ years. Odds ratios (OR), 95% confidence intervals (CI), and tests for trend and effect modification were estimated using unconditional logistic regression adjusted for age and gender. ORs are reported for the highest vs. lowest exposure category or as the ordinal OR for SNPs. Results. The mean age of diagnosis/enrollment was 61 years for cases and 60 years for controls. The most common subtypes were chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; 34%), follicular (FL; 24%), and diffuse large B-cell (DLBCL; 18%) lymphomas. There was a significant decrease in NHL risk with increased sun exposure at ages 13-21 years (OR=0.66, 95% CI 0.44-1.00; ptrend=0.04), which attenuated with increasing age at exposure. Exploratory analysis by NHL subtype indicated a trend toward a protective effect of sun exposure at ages 13-21 years for each of the major subtypes, though these estimates did not reach statistical significance. Of the 38 SNPs evaluated, there was a significant association for 3 SNPs in VDR and 1 SNP in CYP24A1: rs3819545 (OR=1.24, 95% CI 1.10-1.40, p=0.0004), rs2239186 (OR=1.22, 95% CI 1.05-1.41, p=0.009), and rs886441 (OR=0.82, 95% CI 0.70-0.96, p=0.02) for VDR and rs2762939 (OR=0.85, 95% CI 0.75-0.98, p=0.02) for CYP24A1. Both the VDR and CYP24A1 associations were observed for CLL/SLL, FL, but were attenuated for DLBCL. There was no evidence of any significant effect modification of sun exposure at ages 13-21 years by genotype in these four SNPs for NHL overall, or for NHL subtypes. Conclusions. We observed an inverse association between the frequency of sun exposure at ages 13-21 years and NHL risk, which attenuated for sun exposure at older ages, suggesting that early life exposure may be more relevant. While genetic variation in VDR and CYP24A1 were associated with NHL risk, there was no evidence for an interaction of sun exposure with these genes, suggesting that a sun association may not act through the vitamin D metabolism pathway. This would be consistent with a lack of association of circulating vitamin D with NHL risk recently published from the Cohort Consortium pooling project. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1894. doi:10.1158/1538-7445.AM2011-1894

Abstract Background: NHL is a malignancy of lymphocytes, and there is growing evidence for a role of immune dysfunction in the etiology of this malignancy. We conducted a 2-stage analysis of single nucleotide polymorphisms (SNPs) from 1,253 genes using the ParAllele (now Affymetrix) Immune and Inflammation Panel with risk of NHL. Methods: In Stage 1, we successfully genotyped 7,670 SNPs in a clinic-based study of 425 NHL cases and 465 frequency matched controls seen at the Mayo Clinic. Genes were tagged with SNPs from HapMap to provide coverage at r2 = 0.8 and minor allele frequency (MAF) >0.05. In Stage 2, we genotyped the top 768 SNPs on an additional 584 cases and 768 controls from the Mayo Clinic Study, and then conducted a pooled analysis of all 1009 cases and 1233 controls. The association of individual SNPs with NHL risk was assessed using the Odds Ratios (ORs) and 95% confidence intervals, adjusted for age and gender. The most prevalent homozygous genotype was used as the reference group, and each SNP was modeled individually as having a log-additive effect. Results: Overall, the mean age at diagnosis was 62.0 years for cases and the mean age at enrollment for controls was 61.1 years. The most common subtypes were chronic lymphocytic leukemia (CLL, N=343), follicular lymphoma (FL, N=245), and diffuse large B-cell lymphoma (DLBCL, N=178). In the pooled analysis, there were 3 SNPs at p<0.0004. The top SNP was rs241447 (MAF=0.26) from TAP2 at 6p21.3 (OR=1.34, 95% CI 1.17-1.53, p=0.00003). This SNP is a cSNP that leads to a missense change (Ala→Thr). The second SNP was rs2857597 (MAF=0.26) from AIF1, also at 6p21.3 (OR=0.77, 95% CI 0.67-0.88, p=0.0002). The region spanning these two SNPs had multiple risk SNPs with p<0.01, including SNPs in BAT2 (rs3132453), BAT3 (rs2242656), C2 (rs7746553), HLA-DRA (rs8084, rs7192), and TAP2 (rs1894408). Of these SNPs, only rs241447 (TAP2) and rs7192 (HLA-DRA) displayed any substantial LD (r2=0.84, all other r2<0.25). The third SNP was rs754505 (MAF=0.07) from NFATC1 at 18q23 (OR=0.63, 95% CI 0.49-0.81, p=0.0003). There were 4 additional SNPs in this gene with a p<0.05 (rs7240932, rs396127, rs177820, rs183374). In subtype analysis, the SNPs from 6p21.3 showed the strongest associations with FL (including the TAP2 SNP rs241447, p=6.9 × 10−8), although there were also associations with CLL (except for the TAP2 and C2 SNPs) and DLBCL (except for the HLA-DRA SNPs). For NFATC1 the associations were similar across the main NHL subtypes. Conclusions: We identified strong associations with NHL risk in the 6p21.3 region, which includes the MHC locus. Our results were particularly striking for FL and supports recent GWAS and candidate gene studies that implicate this region. We also identified NFATC1 as a susceptibility gene. NFATC1 is known to regulate the expression of growth and survival genes including MYC, TNF, CD40L, and BAFF, all of which have also been linked to lymphomagenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2761. doi:10.1158/1538-7445.AM2011-2761

SummaryThe pathological background in nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) consists of lymphocytes and histocytes. This study analysed the peripheral blood absolute lymphocyte count/absolute monocyte count ratio at diagnosis (ALC/AMC‐DX) on the impact of survival inNLPHL. One hundred and three consecutiveNLPHLpatients that were followed atMayoClinic from 1974 to 2010 were included in the study. Receiver operating characteristic and area under the curve were used forALC/AMC‐DXcut‐off value analysis and proportional‐hazards models were used to compare survival based on theALC/AMC‐DXratio. With a median follow‐up of 8·9 years (range: 0·3–31 years), anALC/AMC‐DX≥2·1 was the best cut‐off value for survival with an area under the curve of 0·82, a sensitivity of 70% and specificity of 84%. After adjusting for theInternationalPrognosticScore (IPS),ALC/AMC‐DXremained an independent prognostic factor for overall survival [HazardRatio (HR), 0·33, 95% confidence interval (CI), 0·15–0·71%,P < 0·004]; lymphoma‐specific survival (HR, 0·05; 95%CI, 0·01–0·68%,P < 0·002); progression‐free survival (HR, 0·30; 95%CI, 0·14–0·60%,P < 0·006), and time to progression (HR, 0·06, 95%CI, 0·04–0·30%,P < 0·004).ALC/AMC‐DXis a low cost, already standarized, biomarker to predict clinical outcomes inNLPHL.

To gain insight into the genomic basis of diffuse large B-cell lymphoma (DLBCL), we performed massively parallel whole-exome sequencing of 55 primary tumor samples from patients with DLBCL and matched normal tissue. We identified recurrent mutations in genes that are well known to be functionally relevant in DLBCL, including MYD88 , CARD11 , EZH2 , and CREBBP . We also identified somatic mutations in genes for which a functional role in DLBCL has not been previously suspected. These genes include MEF2B , MLL2 , BTG1 , GNA13 , ACTB , P2RY8 , PCLO , and TNFRSF14 . Further, we show that BCL2 mutations commonly occur in patients with BCL2 / IgH rearrangements as a result of somatic hypermutation normally occurring at the IgH locus. The BCL2 point mutations are primarily synonymous, and likely caused by activation-induced cytidine deaminase–mediated somatic hypermutation, as shown by comprehensive analysis of enrichment of mutations in WRCY target motifs. Those nonsynonymous mutations that are observed tend to be found outside of the functionally important BH domains of the protein, suggesting that strong negative selection against BCL2 loss-of-function mutations is at play. Last, by using an algorithm designed to identify likely functionally relevant but infrequent mutations, we identify KRAS , BRAF , and NOTCH1 as likely drivers of DLBCL pathogenesis in some patients. Our data provide an unbiased view of the landscape of mutations in DLBCL, and this in turn may point toward new therapeutic strategies for the disease.

Abstract In classical Hodgkin lymphoma, circulating clonotypic malignant cells express CD20, which potentially explains the observed activity of rituximab. This multicenter phase 2 study investigated the combination of rituximab-ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) for stage II-IV untreated classical Hodgkin lymphoma. A goal was to assess the behavior of circulating clonotypic B cells clinically. Of 49 evaluable patients, 69% had stage IIB-IV disease; 8% had CD20+ Hodgkin and Reed-Sternberg cells. Rituximab-ABVD was generally well tolerated. Delivered relative dose intensity was 94% for AVD and 79% for bleomycin. After 6 cycles, 81% of patients were in complete remission. Only 8% received radiation therapy. The actuarial 3-year event-free and overall survival rates were 83% and 98%, respectively. EBV copy number in plasma fell dramatically during cycle 1 in patients with EBV+ tumors. Persistence of detectable circulating clonotypic B cells was associated with a greater relapse frequency (P < .05). Rituximab-ABVD and clonotypic B cells warrant additional study in classical Hodgkin lymphoma. This trial was registered at www.clinicaltrials.gov as NCT00369681.