Citations

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.)

Abstract Non-Hodgkin's lymphoma (NHL) is a cancer closely associated with immune function, and the tumor necrosis factor (TNF) G-308A promoter polymorphism, which influences immune function and regulation, was recently reported by the InterLymph Consortium to be associated with NHL risk. TNF signaling activates the nuclear factor-κB (NF-κB) canonical pathway, leading to transcriptional activation of multiple genes that influence inflammation and immune response. We hypothesized that, in addition to TNF signaling, common genetic variation in genes from the NF-κB canonical pathway may affect risk of NHL. We genotyped 54 single nucleotide polymorphisms (SNP) within TNF, lymphotoxin A LTA, and nine NF-κB genes from the canonical pathway (TNFRSF1A, TRADD, TRAF2, TRAF5, RIPK1, CHUK, IKBKB, NFKB1, and REL) in a clinic-based study of 441 incident cases and 475 frequency-matched controls. Tagging SNPs were selected from HapMap supplemented by putative functional SNPs for LTA/TNF. We used principal components and haplo.stats to model gene-level associations and logistic regression to model SNP-level associations. Compared with the wild-type (GG), the AA genotype for the TNF promoter polymorphism G-308A (rs1800629) was associated with increased risk of NHL [odds ratio (OR), 2.14; 95% confidence interval (95% CI), 0.94-4.85], whereas the GA genotype was not (OR, 1.00; 95% CI, 0.74-1.34). This association was similar for follicular lymphoma and diffuse large B-cell lymphoma. A previously reported LTA/TNF haplotype was also associated with NHL risk. In gene-level analysis of the NF-κB pathway, only NFKB1 showed a statistically significant association with NHL (P = 0.049), and one NFKB1 tagSNP (rs4648022) was associated with NHL risk overall (ordinal OR, 0.59; 95% CI, 0.41-0.84; Ptrend = 0.0037) and for each of the common subtypes. In conclusion, we provide additional evidence for the role of genetic variation in TNF and LTA SNPs and haplotypes with risk of NHL and also provide some of the first preliminary evidence for an association of genetic variation in NFKB1, a downstream target of TNF signaling, with risk of NHL. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3161–9)

Smaller-scale evaluations suggest that common genetic variation in candidate genes related to immune function may predispose to the development of non-Hodgkin lymphoma (NHL). We report an analysis of variants within genes associated with immunity and inflammation and risk of NHL using a panel of 9412 single-nucleotide polymorphisms (SNPs) from 1253 genes in a study of 458 patients with NHL and 484 frequency-matched controls. We modeled haplotypes and risk of NHL, as well as the main effects for all independent SNPs from a gene in multivariate logistic regression models; we separately report results for nonsynonymous (ns) SNPs. In gene-level analyses, the strongest findings (P ≤ .001) were for CREB1, FGG, MAP3K5, RIPK3, LSP1, TRAF1, DUSP2, and ITGB3. In nsSNP analyses, the strongest findings (P ≤ .01) were for ITGB3 L59P (odds ratio [OR] = 0.66; 95% confidence interval [CI] 0.52-0.85), TLR6 V427A (OR = 5.20; CI 1.77-15.3), SELPLG M264V (OR = 3.20; CI 1.48-6.91), UNC84B G671S (OR = 1.50; CI 1.12-2.00), B3GNT3 H328R (OR = 0.74; CI 0.59-0.93), and BAT2 V1883L (OR = 0.64; CI 0.45-0.90). Our results suggest that genetic variation in genes associated with immune response (TRAF1, RIPK3, BAT2, and TLR6), mitogen-activated protein kinase (MAPK) signaling (MAP3K5, DUSP2, and CREB1), lymphocyte trafficking and migration (B3GNT3, SELPLG, and LSP1), and coagulation pathways (FGG and ITGB3) may be important in the etiology of NHL, and should be prioritized in replication studies.

Abstract Chronic lymphocytic leukemia (CLL) and other B-cell lymphoproliferative disorders display familial aggregation. To identify a susceptibility gene for CLL, we assembled families from the major European (ICLLC) and American (GEC) consortia to conduct a genome-wide linkage analysis of 101 new CLL pedigrees using a high-density single nucleotide polymorphism (SNP) array and combined the results with data from our previously reported analysis of 105 families. Here, we report on the combined analysis of the 206 families. Multipoint linkage analyses were undertaken using both nonparametric (model-free) and parametric (model-based) methods. After the removal of high linkage disequilibrium SNPs, we obtained a maximum nonparametric linkage (NPL) score of 3.02 (P = .001) on chromosome 2q21.2. The same genomic position also yielded the highest multipoint heterogeneity LOD (HLOD) score under a common recessive model of disease susceptibility (HLOD = 3.11; P = 7.7 × 10−5), which was significant at the genome-wide level. In addition, 2 other chromosomal positions, 6p22.1 (corresponding to the major histocompatibility locus) and 18q21.1, displayed HLOD scores higher than 2.1 (P < .002). None of the regions coincided with areas of common chromosomal abnormalities frequently observed in CLL. These findings provide direct evidence for Mendelian predisposition to CLL and evidence for the location of disease loci.

AbstractBuilding on the prior work of use of pentostatin in chronic lymphocytic leukemia (CLL), we initiated a trial of combined pentostatin (2 mg/m2), cyclophosphamide (600 mg/m2), and rituximab (375 mg/m2) for 65 symptomatic, previously untreated patients. Of 64 evaluable patients, 34 (53%) were high Rai risk, 71% were nonmutated for the immunoglobulin heavy-chain variable region gene, 34% were CD38+, and 34% were ZAP-70+. Thirty patients (52%) had one anomaly detected by fluorescence in situ (FISH) hybridization, and 21 (36%) had complex FISH defects. Thirty-eight patients (58%) had grade 3+ hematologic toxicity but minimal transfusion needs and no major infections. Responses occurred in 58 patients (91%), with 26 (41%) complete responses (CRs), 14 (22%) nodular partial responses (nodular PRs), and 18 (28%) partial responses (PRs). Many patients with a CR also lacked evidence of minimal residual disease by 2-color flow cytometry. Examination of prognostic factors demonstrated poor response in the 3 patients with del(17p). In contrast, we found this regimen was equally effective in young versus older (> 70 years) patients and in del(11q22.3) versus other favorable prognostic factors. Thus, this novel regimen of pentostatin, cyclophosphamide, and rituximab for previously untreated patients with CLL demonstrated significant clinical activity despite poor risk-based prognoses, achievement of minimal residual disease in some, and modest toxicity.

Purpose Retrospective studies suggest cytogenetic abnormalities detected by interphase fluorescent in situ hybridization (FISH) can identify patients with chronic lymphocytic leukemia (CLL) who will experience a more aggressive disease course. Other studies suggest that patients may acquire chromosome abnormalities during the course of their disease. There are minimal prospective data on the clinical utility of the widely used hierarchical FISH prognostic categories in patients with newly diagnosed early-stage CLL or the frequency of clonal evolution as determined by interphase FISH. Patients and Methods Between 1994 and 2002, we enrolled 159 patients with previously untreated CLL (83% Rai stage 0/I) on a prospective trial evaluating clonal evolution by FISH. Patients provided baseline and follow-up specimens for FISH testing during 2 to 12 years. Results Chromosomal abnormalities detected by FISH at study entry predicted overall survival. Eighteen patients experienced clonal evolution during follow-up. The rate of clonal evolution increased with duration of follow-up with only one occurrence in the first 2 years (n = 71; 1.4%) but 17 occurrences (n = 63; 27%) among patients tested after 5+ years. Clonal evolution occurred among 10% of ZAP-70–negative and 42% of ZAP-70–positive patients at 5+ years (P = .008). Conclusion This clinical trial confirms prospectively that cytogenetic abnormalities detected by FISH can predict overall survival for CLL patients at the time of diagnosis, but also suggests that many patients acquire new abnormalities during the course of their disease. Patients with higher ZAP-70 expression may be more likely to experience such clonal evolution. These findings have important implications for both clinical management and trials of early treatment for patients with high-risk, early-stage CLL.

Purpose Serum B-lymphocyte stimulator (BLyS) levels have been found to be elevated in a number of immune disease models. Therefore, we sought to establish whether BLyS levels were elevated in patients with B-cell lymphoproliferative disorders and to determine whether elevated BLyS levels correlated with clinical characteristics of the disease. Patients and Methods Specimens were collected from the peripheral blood of individuals diagnosed with B-cell chronic lymphocytic leukemia (B-CLL; n = 70) or from age- and sex-matched patients seen at the same institution (n = 41). Serum BLyS levels were determined by enzyme-linked immunosorbent assay, and sequencing of the BLyS promoter was performed by conventional methods and confirmed by restriction fragment length polymorphism analysis. Results We found that elevated BLyS levels were more common in patients with familial B-CLL than individuals with sporadic B-CLL or normal controls. Because of this association, we sequenced the BLyS promoter in patients with B-CLL and normal controls and identified a polymorphic site, −871 C/T. We found that the wild-type sequence was significantly underrepresented in patients with familial B-CLL (4%) compared with patients with sporadic B-CLL (30%; P = .01) or controls (24%; P = .04). Furthermore, using a luciferase reporter under control of the BLyS promoter containing either a C or a T at position −871, we found that the reporter construct containing a T at −871 had a 2.6-fold increase in activity (P = .004). Conclusion Our data suggest serum BLyS levels are elevated in patients with familial B-CLL and that elevated BLyS levels correlate with the presence of a T at −871 in the BLyS promoter.