Kay, Neil E.

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

Abstract We performed a meta-analysis of 3 genome-wide association studies to identify additional common variants influencing chronic lymphocytic leukemia (CLL) risk. The discovery phase was composed of genome-wide association study data from 1121 cases and 3745 controls. Replication analysis was performed in 861 cases and 2033 controls. We identified a novel CLL risk locus at 6p21.33 (rs210142; intronic to the BAK1 gene, BCL2 antagonist killer 1; P = 9.47 × 10−16). A strong relationship between risk genotype and reduced BAK1 expression was shown in lymphoblastoid cell lines. This finding provides additional support for polygenic inheritance to CLL and provides further insight into the biologic basis of disease development.

Purpose To delineate outcomes of malignant melanoma (MM) and Merkel cell carcinoma (MCC) in patients with chronic lymphocytic leukemia (CLL) or non-Hodgkin's lymphoma (NHL). Patients and Methods We identified patients with MM or MCC reported to the Surveillance, Epidemiology, and End Results program and analyzed the effects of history of CLL/NHL on overall (OS) and cause-specific survival after MM or MCC. Expected survival was derived from patients with MM or MCC without CLL/NHL. Results From 1990 to 2006, 212,245 patients with MM and 3,613 patients with MCC were identified, of whom 1,246 with MM and 90 with MCC had a prior diagnosis of CLL/NHL. Patients with MM and a history of CLL/NHL had worse-than-expected OS as measured by standardized mortality ratio (SMR; SMR for CLL, 2.6; 95% CI, 2.3 to 3.0; SMR for NHL, 2.3; 95% CI, 2.1 to 2.6). MM cause-specific survival was worse than expected for patients with a history of CLL (SMR, 2.8; 95% CI, 2.2 to 3.4) or NHL (SMR, 2.1; 95% CI, 1.7 to 2.6). Among patients with MCC, OS was worse than expected for those with a history of CLL (SMR, 3.1; 95% CI, 2.2 to 4.3) or NHL (SMR, 1.9; 95% CI, 1.3 to 2.8). MCC cause-specific survival was worse than expected for patients with a history of CLL (SMR, 3.8; 95% CI, 2.5 to 5.9), but no difference was observed for NHL (SMR, 0.9; 95% CI, 0.4 to 2.1). Conclusion Patients with CLL before diagnosis of MM or MCC have significantly worse OS and MM or MCC cause-specific survival than those without a history of CLL/NHL.

AbstractFree light chains (FLCs) are the most commonly detected paraproteins in chronic lymphocytic leukemia (CLL). We examined the types of FLC abnormalities and prognostic utility of the FLC assay compared with standard prognostic biomarkers in a prospective cohort of 339 patients with newly diagnosed CLL. Three types of FLC abnormalities were identified: monoclonal elevated FLC (elevated κ and/or λ with abnormal FLC ratio), polyclonal elevated FLC (elevated κ and/or λ with normal FLC ratio), and ratio-only FLC abnormality (normal range κ and λ with abnormal FLC ratio). One hundred sixty-five patients (49%) had a FLC abnormality with approximately equal distribution among monoclonal elevation, polyclonal elevation, and ratio-only abnormality. All FLC abnormalities were associated with poor time to first treatment: monoclonal FLC (hazard ratio [HR], 4.99; 95% confidence interval [CI], 2.94-8.48), polyclonal FLC (HR, 2.40; 95% CI, 1.24-4.64), ratio-only FLC (HR, 2.57; 95% CI, 1.40-4.69). Monoclonal FLC and polyclonal FLC were associated with poor overall survival compared with patients with normal FLC. Results remained significant after adjusting for Rai stage. The FLC assay is a simple, widely available clinical test with similar prognostic utility as routinely used prognostic biomarkers for CLL. Among persons with FLC abnormalities, the type of abnormality affects prognostic significance.

The treatment of chronic lymphocytic leukemia (CLL) has evolved over the past decade. Our better understanding of disease biology and risk stratification has allowed delivering more effective therapies. In fact, front-line chemoimmunotherapy has demonstrated improvement in overall survival when compared to chemotherapy in randomized studies. Yet, treatment of relapsed CLL remains challenging and few agents are effective in that setting. Ofatumumab (Ofa) is a humanized monoclonal antibody targeted against CD20 with demonstrable activity in rituximab-resistant CLL cell lines. This agent was recently approved for the treatment of relapsed/refractory CLL patients who have failed fludarabine and alemtuzumab. In this review, we provide a historical perspective on approaches to CLL as front-line and in the relapsed setting. We further summarize novel anti-CD20 antibodies with specific emphasis on ofa. We review studies that led to ofatumumab's approval including pre-clinical data, trials using ofa in combination therapies, and adverse events/toxicities reported with this agent.

Abstract Background. MBL is defined as a monoclonal expansion of B lymphocytes (< 5 × 109/L) in the blood without associated lymphadenopathy or organomegaly; MBLs with a chronic lymphocytic leukemia (CLL) immunophenotype have been termed as CLL-like MBL. The prevalence of CLL-like MBL in the general population is 3.5-12% but increases with age; however, the frequency is even higher (∼13-18%) among unaffected relatives from CLL families (i.e., families with two or more CLL members). We and others have found that a small proportion of individuals with CLL-like MBL individuals and lymphocytosis will progress to CLL requiring treatment (∼1.1% per year). Because CLL and NHL have been shown to aggregate together within families, suggesting a shared pathogenesis, we evaluated the frequency of MBL in NHL families. Methods. Individuals were obtained from an ongoing study of NHL families (i.e., families with 2 or more NHL members). However, we limited to NHL families with at most 1 individual with CLL due to the known increased frequency of MBL in CLL families. Multi-color flow cytometry was performed on fresh peripheral blood samples. A CBC and differential count was simultaneously obtained using an automated blood cell counter. Five possible flow diagnoses were defined as: CLL-like MBL (CD5+CD20dim), atypical MBL (CD5+CD20bright), non-CLL like MBL (CD5−), and normal immunophenotype (NIPT). Medical records of NHL cases were reviewed to confirm disease. Results. A total of 30 individuals from 16 NHL families had available flow cytometry results. The mean age at flow analysis was 56 years (range 37− 83 years). We identified 5 individuals with MBL from 4 families: 3 of the 6 had CLL-like MBL, 1 had atypical MBL, and 1 had non-CLL like MBL. The remaining 25 individuals had a NIPT. Thus, the MBL rate in NHL families is 17% (5/30). Among the CD5+ MBL (both CLL-like and atypical MBL) individuals, all were female and the mean absolute lymphocyte count was 1.4 × 109/L. Of interest, 1 of the CLL-like MBL individuals is from a family where two members had monoclonal gammopathy of uncertain significance (MGUS). Conclusion: Our data show that MBLs of various phenotypes can be found at a higher prevalence in NHL families than that of the general population. Further, the frequency of MBL in NHL families is comparable to that of CLL families. Although more work is needed, our results suggest that MBL may be clustering within NHL families, and thus support a possible common inherited predisposition of NHL and CLL, with MBL signifying a shared early pathogenetic step. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1853.

Abstract Background: Obesity has been linked to NHL risk in some studies, and may be stronger for obesity in early adulthood (ages 18-20). There has only been limited evaluation of physical activity and risk of NHL, particularly physical activity earlier in life. The purpose of this study was to evaluate the association of body mass index (BMI), physical activity (PA), and NHL risk during adulthood and at age 18. Methods: Self-reported anthropometrics and PA were collected in a clinic-based study of 954 newly diagnosed NHL cases and 1146 controls enrolled at the Mayo Clinic from 2002-2008. PA variables included duration and frequency of mild, moderate, and strenuous PA two years prior to case diagnosis or control selection, strenuous activity at age 18 (any vs. none), and height and weight at both time periods. An overall PA index was estimated by weighting the reported duration and frequency of each PA intensity by the average energy requirement (defined in METs) to obtain an average MET-minutes/week for each participant. BMI was calculated as weight (kg) divided by height (m) squared. Odds Ratios (OR), 95% confidence intervals (CI), and test for trend were estimated using unconditional logistic regression adjusted for the age, gender, and residence. Continuous variables were divided into quartiles according to the distribution among the controls; results are reported for the highest vs. lowest category or quartile unless otherwise specified. Results: The mean age at diagnosis/enrollment was 61 for both cases and controls; 47% and 43% of the cases and controls, respectively, were female. The most common NHL subtypes were CLL/SLL (32%), follicular lymphoma (FL; 26%), and diffuse large B-cell lymphoma (DLBCL; 21%). BMI 2 years prior to diagnosis was not associated with NHL risk (OR=1.21, p-trend=0.13), while there was a positive association with BMI at age 18 (OR=1.40, p-trend=0.001). There was no association of the PA index with risk (OR=0.91, p-trend=0.29). Furthermore, frequency of walking (OR=0.71, p-trend 0.43), mild (OR=1.30, p-trend=0.64), moderate (OR=0.99, p-trend=0.75), and strenuous (OR=0.77, p-trend=0.20) PA were not associated with NHL risk when evaluated individually. However, there was a suggestive weak inverse association between strenuous activity at age 18 and NHL risk (OR=0.85, 95% CI 0.71-1.05). On exploratory analysis, the association of BMI at age 18 with NHL risk was specific to DLBCL (OR=1.84, p-trend=0.002) and CLL/SLL (OR=1.25, p-trend=0.044) but not FL; all other results were similar across these subtypes. Conclusions: We did not observe an association between adult BMI and NHL risk; however a higher BMI in early adulthood was associated with NHL risk, consistent with limited prior reports. We found little evidence to support an association between PA in either early adulthood or later in life and NHL risk. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1833.

Abstract Recently, we detected that chronic lymphocytic leukemia (CLL) B-cell–derived microvesicles in CLL plasma carry a constitutively phosphorylated novel receptor tyrosine kinase (RTK), Axl, indicating that Axl was acquired from the leukemic B cells. To examine Axl status in CLL, we determined the expression of phosphorylated-Axl (P-Axl) in freshly isolated CLL B cells by Western blot analysis. We detected differential levels of P-Axl in CLL B cells, and further analysis showed that expression of P-Axl was correlated with the other constitutively phosphorylated kinases, including Lyn, phosphoinositide-3 kinase, SyK/ζ-associated protein of 70 kDa, phospholipase C γ2 in CLL B cells. We found that these intracellular signaling molecules were complexed with P-Axl in primary CLL B cells. When Axl and Src kinases were targeted by a Src/Abl kinase inhibitor, bosutinib (SKI-606), or a specific-inhibitor of Axl (R428), robust induction of CLL B-cell apoptosis was observed in both a dose- and time-dependent manner. Therefore, we have identified a novel RTK in CLL B cells which appears to work as a docking site for multiple non-RTKs and drives leukemic cell survival signals. These findings highlight a unique target for CLL treatment.

Abstract Prior genome-wide association (GWA) studies have identified 10 susceptibility loci for risk of chronic lymphocytic leukemia (CLL). To identify additional loci, we performed a GWA study in 407 CLL cases (of which 102 had a family history of CLL) and 296 controls. Moreover, given the strong familial risk of CLL, we further subset our GWA analysis to the CLL cases with a family history of CLL to identify loci specific to these familial CLL cases. Our top hits from these analyses were evaluated in an additional sample of 252 familial CLL cases and 965 controls. Using all available data, we identified and confirmed an independent association of 4 single-nucleotide polymorphisms (SNPs) that met genome-wide statistical significance within the IRF8 (interferon regulatory factor 8) gene (combined P values ≤ 3.37 × 10−8), located in the previously identified 16q24.1 locus. Subsetting to familial CLL cases, we identified and confirmed a new locus on chromosome 6p21.3 (combined P value = 6.92 × 10−9). This novel region harbors the HLA-DQA1 and HLA-DRB5 genes. Finally, we evaluated the 10 previously reported SNPs in the overall sample and replicated 8 of them. Our findings support the hypothesis that familial CLL cases have additional genetic variants not seen in sporadic CLL. Additional loci among familial CLL cases may be identified through larger studies.

Abstract Background: The t(14;18)(q32;q21) translocation is the most commonly observed chromosomal translocation in non–Hodgkin's lymphoma (NHL), resulting in constitutive Bcl-2 expression and apoptosis inhibition. In addition, germline variation in both BCL2L11 (BIM) and CASP9, known regulators of apoptosis, has recently been linked to NHL risk. We conducted a comprehensive evaluation of 36 apoptosis pathway genes with risk of NHL. Methods: We genotyped 226 single-nucleotide polymorphisms (SNP) from 36 candidate genes in a clinic-based study of 441 newly diagnosed NHL cases and 475 frequency-matched controls. We used principal components analysis to assess gene-level associations, and logistic regression to assess SNP-level associations. MACH was used for imputation of SNPs in BCL2L11 and CASP9. Results: In gene-level analyses, BCL2L11 (P = 0.0019), BCLAF1 (P = 0.0097), BAG5 (P = 0.026), and CASP9 (P = 0.0022) were associated with NHL risk after accounting for multiple testing (tail strength, 0.38; 95% confidence interval, 0.05-0.70). Two of the five BCL2L11 tagSNPs (rs6746608 and rs12613243), both genotyped BCLAF1 tagSNPs (rs797558 and rs703193), the single genotyped BAG5 tagSNP (rs7693), and three of the seven genotyped CASP9 tagSNPs (rs6685648, rs2020902, and rs2042370) were significant at P < 0.05. We successfully imputed BCL2L11 and CASP9 SNPs previously linked to NHL, and replicated all four BCL2L11 and two of three CASP9 SNPs. Conclusion: We replicated the association of BCL2L11 and CASP9 with NHL risk at the gene and SNP level, and identified novel associations with BCLAF1 and BAG5. Impact: Closer evaluation of germline variation of genes in the apoptosis pathway with risk of NHL and its subtypes is warranted. Cancer Epidemiol Biomarkers Prev; 19(11); 2847–58. ©2010 AACR.