Glutathione-S-transferase genotypes influence prognosis in follicular non-Hodgkin's Lymphoma

Role of glutathione-S-transferase (GST) polymorphisms in patients with advanced Hodgkin lymphoma: results from the HD2000 GISL trial

Polymorphisms of the Glutathione-S Transferase (GST) family may influence the prognosis in lymphoma patients. We aimed to validate the impact of GSTT1 and GSTM1 deletions and of the GSTP1Ile105Val polymorphism on outcome and toxicity in 140 patients with advanced Hodgkin's lymphoma enrolled in the prospective multicenter HD2000-GISL trial, comparing ABVD, BEACOPP and CEC regimens. Carriers of the GSTP1Ile105Val polymorphism had a higher rate of grade 3-4 anemia following treatment. Overall, our study failed to validate GST genotyping as prognostic factor for progression-free survival (PFS). Only the small cohort of patients with an international prognostic score (IPS) >3 and undeleted GSTT1 and/or GSTM1, treated with ABVD had worse progression-free survival (PFS) (GSTT1 + vs GSTT1-: HR 5.02, 95% C.I., 1.16-21.8, p = 0.031, GSTM1 + /GSTT1 + vs GSTM1-and/or GSTT1-: HR 4.61, 95% C.I. 1.28- 16.6, p = 0.019, respectively). No differences were observed for patients treated with intensified regimens, as BEACOPP and CEC. In conclusion, the prognostic role of GST polymorphism, if at all, is limited to a small subgroup of patients treated with standard ABVD regimen.

Risk Factors of Non-Hodgkin Lymphoma

INTRODUCTION: Despite decades of intensive research, Non-Hodgkin Lymphoma (NHL) remains poorly understood and is largely incurable. NHL is a heterogeneous group of malignancies with multiple subtypes, each of which has distinct morphologic, immunophenotypic, and clinical features. Identifying the risk factors for NHL may improve our understanding of the underlying biological mechanisms and have an impact on clinical practice. AREAS COVERED: This article provides a review of several aspects of NHL, including epidemiology and subtype classification, clinical, environmental, genetic, and genomic risk factors identified for etiology and prognosis, and available statistical and bioinformatics tools for identification of genetic and genomic risk factors from the analysis of high-throughput studies. EXPERT OPINION: Multiple clinical and environmental risk factors have been identified. However, they have failed to provide practically effective prediction. Genetic and genomic risk factors identified from high-throughput studies have suffered a lack of reproducibility. The identification of genetic/genomic risk factors demands innovative statistical and bioinformatics tools. Although multiple analysis methods have been developed, there is still room for improvement. There is a critical need for well-designed, prospective, large-scale pangenomic studies.

Host genetics in follicular lymphoma

The role of inherited (host) genetic susceptibility in the pathogenesis of follicular lymphoma (FL) is reviewed. First degree relatives of FL patients are at an increased risk of FL, suggesting a role for inherited factors. While there have been no linkage studies in FL families, candidate gene and genome-wide association studies have identified several risk loci which have been confirmed in independent studies. These include regions on 6p21.32-33 and TNF family members. Host genetics has also been hypothesized to influence treatment response, disease progression and overall survival. Early leads in FL prognosis include pathways that regulate immune function, antibody-dependent cellular cytotoxicity, chemotaxis, and one-carbon metabolism, although few of these associations have been independently confirmed. While the use of host genetics to identify individuals at high risk of FL or to predict FL treatment response and prognosis appears to be very promising, it is not yet ready for the clinic.

A multiplex MALDI-TOF MS approach facilitates genotyping of DNA from formalin-fixed paraffin-embedded tumour specimens

OBJECTIVE

The impact of single-nucleotide polymorphisms (SNPs) on tumour susceptibility and pathogenesis has gained enormous attention. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based genotyping facilitates the analysis of short DNA amplicons and is, therefore, a promising tool for the investigation of formalin-fixed paraffin-embedded (FFPE) tissue samples, particularly in targeted genotyping analysis.

METHODS

To examine the applicability of genotyping FFPE DNA with MALDI-TOF MS in multiplex reactions, we investigated five DNA samples extracted from FFPE tumour specimens from follicular lymphoma patients using different extraction methods (phenol-chloroform, commercial kit). Thirty-one SNPs from 25 genes, integrated in different-sized multiplex assays (7-plex, 10-plex, 14-plex, 24-plex), were analyzed. To investigate the reliability of genotyping tumour-derived DNA extracted from FFPE tissue, we examined 64 FFPE tumour specimens in comparison with matched germline DNA samples.

RESULTS

Call rates of 99.6 (274/275) and 93.5% (257/275) were observed for the DNA extracted with the phenol-chloroform approach or the commercial extraction kit, respectively. Increasing the number of SNPs per assay resulted in reduced genotyping call rates and genotyping quality, especially in the DNA samples isolated with the commercial extraction kit. When comparing the genotypes of DNA derived from germline and tumour (FFPE) specimens, a perfect concordance rate of 100% was detected.

CONCLUSION

Our data delineate that MALDI-TOF-based genotyping of FFPE DNA is reliable and reproducible even in multiplex reactions, enabling the retrospective investigation of FFPE study cohorts in future experiments.

SNP rs6457327 in the HLA region on chromosome 6p is predictive of the transformation of follicular lymphoma

Inherited risk determinants for follicular lymphoma (FL) have recently been described in the immune gene-rich human leukocyte antigen region on chromosome 6p. The known importance of host immune response to FL survival led us to evaluate these germline factors in FL outcome. We confirm the association of single nucleotide polymorphisms rs10484561 (P = 3.5 × 10⁻⁹) and rs6457327 (P = .008) with risk of FL and demonstrate that rs6457327 predicts both time to (P = .02) and risk of (P < .01) FL transformation independently of clinical variables, including the Follicular Lymphoma International Prognostic Index.

Smoking, alcohol use, obesity, and overall survival from non-Hodgkin lymphoma: a population-based study

BACKGROUND

Smoking, alcohol use, and obesity appear to increase the risk of developing non-Hodgkin lymphoma (NHL), but to the authors' knowledge, few studies to date have assessed their impact on NHL prognosis.

METHODS

The association between prediagnosis cigarette smoking, alcohol use, and body mass index (BMI) and overall survival was evaluated in 1286 patients enrolled through population-based registries in the United States from 1998 through 2000. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox regression, adjusting for clinical and demographic factors.

RESULTS

Through 2007, 442 patients had died (34%), and the median follow-up for surviving patients was 7.7 years. Compared with never smokers, former (HR, 1.59; 95% CI, 1.12-2.26) and current (HR, 1.50; 95% CI, 0.97-2.29) smokers had poorer survival, and poorer survival was found to be positively associated with smoking duration, number of cigarettes smoked per day, pack-years of smoking, and shorter time since quitting (all P <0.01). Alcohol use was associated with poorer survival (P = 0.03); compared with nonusers. Those drinking >43.1 g/week (median intake among drinkers) had poorer survival (HR, 1.55; 95% CI, 1.06-2.27), whereas those drinkers consuming less than this amount demonstrated no survival disadvantage (HR, 1.13; 95% CI, 0.75-1.71). Greater BMI was associated with poorer survival (P = 0.046), but the survival disadvantage was only noted among obese individuals (HR, 1.32 for BMI > or = 30 vs BMI 20-24.9; 95% CI, 1.02-1.70). These results held for lymphoma-specific survival and were broadly similar for diffuse large B-cell lymphoma and follicular lymphoma.

CONCLUSIONS

NHL patients who smoked, consumed alcohol, or were obese before diagnosis were found to have a poorer overall and lymphoma-specific survival.

Genetic polymorphisms in the metabolic pathway and non-Hodgkin lymphoma survival

Metabolic pathway enzymes, such as Cytochrome P450 (CYP), glutathione S-transferase (GST), and N-acetyltransferases (NAT) are involved in activation and detoxification of environmental carcinogens as well as drug metabolism. We hypothesized that the genetic variations in such metabolic pathways may affect NHL prognosis and survival. Follow-up information of 496 female NHL incident cases diagnosed during 1996-2000 in Connecticut were abstracted from the Connecticut Tumor Registry in 2008; survival analyses were conducted by comparing the Kaplan-Meier curves, and hazard ratios (HR) were computed from the Cox Proportional Hazard models adjusting for demographic and tumor characteristics which were suggested by previous studies to be determinants of NHL survival. We identified six SNPs from four metabolism genes (CYP2E1, GSTP1, GSTT1, and NAT1) that were associated with NHL survival. Specifically, polymorphisms in GSTT1 were associated with follicular lymphoma survival; and polymorphisms in CYP2E1, GSTP1, and NAT1 were associated with survival of chronic lymphocytic leukemia/small lymphocytic lymphoma. Our study suggests that genetic polymorphisms in metabolic pathways may help improve the prediction of NHL survival and prognosis.

Genetic polymorphisms and head and neck cancer outcomes: a review

Head and neck cancer (HNC) patients have variable prognoses even within the same clinical stage and while receiving similar treatments. The number of studies of genetic polymorphisms as prognostic factors of HNC outcomes is growing. Candidate polymorphisms have been evaluated in DNA repair, cell cycle, xenobiotic metabolism, and growth factor pathways. Polymorphisms of XRCC1, FGFR, and CCND1 have been consistently associated with HNC survival in at least two studies, whereas most of the other polymorphisms have either conflicting data or were from single studies. Heterogeneity and lack of description of patient populations and lack of accounting for multiple comparisons were common problems in a significant proportion of studies. Despite a large number of exploratory studies, large replication studies in well-characterized HNC populations are warranted.