Call, Timothy G.

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 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.

Abstract Vitamin D insufficiency is common globally and low levels are linked to higher cancer incidence. Although vitamin D insufficiency is related to inferior prognosis in some cancers, no data exist for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We evaluated the relationship of 25(OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and a separate cohort of previously untreated patients participating in an observational study (confirmation cohort). Of 390 CLL patients in the discovery cohort, 119 (30.5%) were 25(OH)D insufficient. After a median follow-up of 3 years, TTT (hazard ratio[HR] = 1.66; P = .005) and OS (HR = 2.39; P = .01) were shorter for 25(OH)D-insufficient patients. In the validation cohort, 61 of 153 patients (39.9%) were 25(OH)D insufficient. After a median follow-up of 9.9 years, TTT (HR = 1.59; P = .05) and OS (HR 1.63; P = .06) were again shorter for 25(OH)D-insufficient patients. On pooled multivariable analysis of patients in both cohorts adjusting for age, sex, Rai stage, CD38 status, ZAP-70 status, immunoglobulin heavy chain variable (IGHV) gene mutation status, CD49d status, and cytogenetic abnormalities assessed by interphase fluorescent in situ hybridization testing, 25(OH)D insufficiency remained an independent predictor of TTT (HR = 1.47; P = .008), although the association with OS was not significant (HR = 1.47; P = .07). Vitamin D insufficiency is associated with inferior TTT and OS in CLL patients. Whether normalizing vitamin D levels in deficient CLL patients would improve outcome merits clinical testing.

The study looks at the high cost of new treatments for chronic lymphocytic leukemia and calls for the consideration of a standardized and transparent method to determine the price of new drugs based on comparative effectiveness.

Abstract Background: There is strong and consistent evidence that a genetic component contributes to the etiology of chronic lymphocytic leukemia (CLL). A recent genome-wide association study of CLL identified seven genetic variants that increased the risk of CLL within a European population. Methods: We evaluated the association of these variants, or variants in linkage disequilibrium with these variants, with CLL risk in an independent sample of 438 CLL cases and 328 controls. Results: Of these seven single nucleotide polymorphisms (SNP), six had P trend < 0.05 and had estimated odds ratios (OR) that were strikingly comparable to those of the previous study. Associations were seen for rs9378805 [OR, 1.47; 95% confidence intervals (CI), 1.19-1.80; P trend = 0.0003] near IRF4 and rs735665 near GRAMD1B (OR, 1.47; 95% CI, 1.14-1.89; P trend = 0.003). However, no associations (P > 0.05) were found for rs11083846, nor were any found for any SNP in linkage disequilibrium with rs11083846. Conclusions: Our results confirm the previous findings and further support the role of a genetic basis in the etiology of CLL; however, more research is needed to elucidate the causal SNP(s) and the potential manner in which these SNPs or linked SNPs function in CLL pathogenesis. Cancer Epidemiol Biomarkers Prev; 19(4); 1098–102. ©2010 AACR.

Purpose The diagnosis of monoclonal B-cell lymphocytosis (MBL) is used to characterize patients with a circulating population of clonal B cells, a total B-cell count of less than 5 × 109/L, and no other features of a B-cell lymphoproliferative disorder including lymphadenopathy/organomegaly. The natural history of clinically identified MBL is unclear. The goal of this study was to explore the outcome of patients with MBL relative to that of individuals with Rai stage 0 chronic lymphocytic leukemia (CLL). Patients and Methods We used hematopathology records to identify a cohort of 631 patients with newly diagnosed MBL or Rai stage 0 CLL. Within this cohort, 302 patients had MBL (B-cell counts of 0.02 to 4.99 × 109/L); 94 patients had Rai stage 0 CLL with an absolute lymphocyte count (ALC) ≤ 10 × 109/L; and 219 patients had Rai stage 0 CLL with an ALC more than 10 × 109/L. Data on clinical outcome were abstracted from medical records. Results The percentage of MBL patients free of treatment at 1, 2, and 5 years was 99%, 98%, and 93%, respectively. B-cell count as a continuous variable (hazard ratio [HR] = 2.9, P = .04) and CD38 status (HR = 10.8, P = .006) predicted time to treatment (TTT) among MBL patients. The likelihood of treatment for MBL patients was lower (HR = 0.32, P = .04) than that of both Rai stage 0 CLL patients with an ALC less than 10 × 109/L (n = 94) and Rai stage 0 CLL patients with an ALC more than 10 × 109/L (n = 219; P = .0003). Conclusion Individuals with MBL identified in clinical practice have a low risk for progression at 5 years. Because B-cell count seems to relate to TTT as a continuous variable, additional studies are needed to determine what B-cell count should be used to distinguish between MBL and CLL.

PurposeSmudge cells are ruptured chronic lymphocytic leukemia (CLL) cells appearing on the blood smears of CLL patients. Our recent findings suggest that the number of smudge cells may have important biologic correlations rather than being only an artifact of slide preparation. In this study, we evaluated whether the smudge cell percentage on a blood smear predicted survival of CLL patients.Patients and MethodsWe calculated smudge cell percentages (ratio of smudged to intact cells plus smudged lymphocytes) on archived blood smears from a cohort of previously untreated patients with predominantly early-stage CLL enrolled onto a prospective observational study. The relationship between percentage of smudge cells, patient survival, and other prognostic factors was explored.ResultsBetween 1994 and 2002, 108 patients were enrolled onto the study and had archived blood smears available for review; 80% of patients had Rai stage 0 or I disease. The median smudge cell percentage was 28% (range, 1% to 75%). The percentage of smudge cells was lower in CD38+versus CD38–patients (P = .019) and in Zap70-positive versus Zap70-negative patients (P = .028). Smudge cell percentage as a continuous variable was associated with prolonged survival (P = .042). The 10-year survival rate was 50% for patients with 30% or less smudge cells compared with 80% for patients with more than 30% of smudge cells (P = .015). In multivariate analysis, the percentage of smudge cells was an independent predictor of overall survival.ConclusionPercentage of smudge cells on blood smear is readily available and an independent factor predicting overall survival in CLL.

Abstract The diagnosis of chronic lymphocytic leukemia (CLL) in asymptomatic patients has historically been based on documenting a characteristic lymphocyte clone and the presence of lymphocytosis. There are minimal data regarding which lymphocyte parameter (absolute lymphocyte count [ALC] or B-cell count) and what threshold should be used for diagnosis. We analyzed the relationship of ALC and B-cell count with clinical outcome in 459 patients with a clonal population of CLL phenotype to determine (1) whether the CLL diagnosis should be based on ALC or B-cell count, (2) what lymphocyte threshold should be used for diagnosis, and (3) whether any lymphocyte count has independent prognostic value after accounting for biologic/molecular prognostic markers. B-cell count and ALC had similar value for predicting treatment-free survival (TFS) and overall survival as continuous variables, but as binary factors, a B-cell threshold of 11 × 109/L best predicted survival. B-cell count remained an independent predictor of TFS after controlling for ZAP-70, IGHV, CD38, or fluorescence in situ hybridization (FISH) results (all P < .001). These analyses support basing the diagnosis of CLL on B-cell count and retaining the size of the B-cell count in the diagnostic criteria. Using clinically relevant criteria to distinguish between monoclonal B-cell lymphocytosis (MBL) and CLL could minimize patient distress caused by labeling asymptomatic people at low risk for adverse clinical consequences as having CLL.

Abstract Myeloid cell leukemia-1 (Mcl-1) is an antiapoptotic member of the Bcl-2 protein family. Increased Mcl-1 expression is associated with failure to achieve remission after treatment with fludarabine and chlorambucil in patients with chronic lymphocytic leukemia (CLL). However, the influence of Mcl-1 expression has not been examined in CLL trials using chemoimmunotherapy. We investigated Mcl-1 protein expression prospectively as part of a phase 2 study evaluating the efficacy of pentostatin, cyclophosphamide, and rituximab in patients with untreated CLL. No significant difference by Mcl-1 expression was noted in pretreatment or response parameters. However, in patients with higher Mcl-1 expression, both minimal residual disease-negative status and progression-free survival was found to be significantly reduced (57% vs 19%, P = .01; 50.8 vs 18.7 months; P = .02; respectively). Mcl-1 expression may therefore be useful in predicting poor response to chemoimmunotherapy. These findings further support pursuing treatment strategies targeting this important antiapoptotic protein. (Because the trials described were conducted before the requirement to register them was implemented, they are not registered in a clinical trial database.)