Genetic variations in multiple myeloma I: effect on risk of multiple myeloma

Association Of -308G/A, -238G/A TNF-α Polymorphisms with Multiple Myeloma Risk and Survival: A Systematic Review and Meta-Analysis

INTRODUCTION

Tumor necrosis factor alpha (TNF-α) is a cytokine with a key role in proinflammation and multiple diseases, including cancer. The gene encoding TNF-α is located within a highly polymorphic region on chromosome 6p21.3; two polymorphisms -308G/A (rs1800629) and -238G/A (rs361525) have been associated with occurrence of human diseases. There is a debate in recent meta-analyses that reached discrepant conclusions regarding the potential role of TNF-α polymorphisms in multiple myeloma (MM) risk. The aim of this systematic review and meta-analysis is to investigate the association between the aforementioned two polymorphisms with the risk and survival of MM.

MATERIALS AND METHODS

Eligible articles were identified through an extensive search in PubMed database (end of search: June 18, 2020). The pooled effect estimates were calculated following the random-effects models by Der Simonian and Laird. Separate analyses were conducted by ethnicity. Between-study heterogeneity was quantified, and the deviation of genotype frequencies in controls from the Hardy-Weinberg equilibrium was evaluated.

RESULTS

Eighteen studies (2934 cases, 4291 controls) have been included in the quantitative synthesis examining risk and 5 studies for survival (557 cases). No association was found between -308G/A and -238G/A TNF-α polymorphisms and MM susceptibility in all genetic models for both Caucasian and East Asian populations. There was no association between -308G/A and -238G/A TNF-α polymorphisms and survival (overall or progression-free) of MM.

CONCLUSION

This systematic review and meta-analysis did not reveal a significant effect of -308G/A and -238G/A TNF-α polymorphisms upon risk or survival of MM.

Genetically determined telomere length and multiple myeloma risk and outcome

Telomeres are involved in processes like cellular growth, chromosomal stability, and proper segregation to daughter cells. Telomere length measured in leukocytes (LTL) has been investigated in different cancer types, including multiple myeloma (MM). However, LTL measurement is prone to heterogeneity due to sample handling and study design (retrospective vs. prospective). LTL is genetically determined; genome-wide association studies identified 11 SNPs that, combined in a score, can be used as a genetic instrument to measure LTL and evaluate its association with MM risk. This approach has been already successfully attempted in various cancer types but never in MM. We tested the "teloscore" in 2407 MM patients and 1741 controls from the International Multiple Myeloma rESEarch (IMMeNSE) consortium. We observed an increased risk for longer genetically determined telomere length (gdTL) (OR = 1.69; 95% CI 1.36-2.11; P = 2.97 × 10^-6 for highest vs. lowest quintile of the score). Furthermore, in a subset of 1376 MM patients we tested the relationship between the teloscore and MM patients survival, observing a better prognosis for longer gdTL compared with shorter gdTL (HR = 0.93; 95% CI 0.86-0.99; P = 0.049). In conclusion, we report convincing evidence that longer gdTL is a risk marker for MM risk, and that it is potentially involved in increasing MM survival.

Multiple Myeloma: Personalised Medicine Based on Pathogenesis

Multiple myeloma is increasingly being recognised as more than one disease, characterised by marked cytogenetic, molecular, and proliferative heterogeneity. The prognosis is widely varied, ranging from low to very high-risk, based on cytogenetic and molecular studies. Although novel agents, such as proteasome inhibitors and immunomodulators, have been developed, which have improved treatment responses and disease prognosis, multiple myeloma remains an incurable disease. Based on highly sensitive detection tools, such as gene expression profiling and next generation sequence analysis, and the understanding of the pathogenesis of multiple myeloma, many potential agents, including monoclonal antibodies, drug-conjugated antibodies, drugs targeted to molecular abnormalities, microRNA inhibitors or mimics, and immune therapies, such as chimeric antigen receptors T cells and anti-PD1 agents, can be considered personalised therapies. In this paper, multiple myeloma pathogenesis and potential molecular and immunotherapies are reviewed.

Multiple myeloma and family history of lymphohaematopoietic cancers: Results from the International Multiple Myeloma Consortium

Family clusters of multiple myeloma (MM) suggest disease heritability. Nevertheless, patterns of inheritance and the importance of genetic versus environmental risk factors in MM aetiology remain unclear. We pooled data from eleven case-control studies from the International Multiple Myeloma Consortium to characterize the association of MM risk with having a first-degree relative with a history of a lympho-haematapoietic cancer. Unconditional logistic regression models, adjusted for study, sex, age and education level, were used to estimate associations between MM risk and having a first-degree relative with a history of non-Hodgkin lymphoma, Hodgkin lymphoma, leukaemia or MM. Sex, African American race/ethnicity and age were explored as effect modifiers. A total of 2843 cases and 11 470 controls were included. MM risk was elevated in association with having a first-degree relative with any lympho-haematapoietic cancer (Odds Ratio (OR) = 1·29, 95% Confidence Interval (CI): 1·08-1·55). The association was particularly strong for having a first-degree relative with MM (OR = 1·90, 95% CI: 1·26-2·87), especially among men (OR = 4·13, 95% CI: 2·17-7·85) and African Americans (OR = 5·52, 95% CI: 1·87-16·27).These results support the hypothesis that genetic inheritance plays a role in MM aetiology. Future studies are warranted to characterize interactions of genetic markers with environmental exposures.

Risk of multiple myeloma is associated with polymorphisms within telomerase genes and telomere length

Compelling biological and epidemiological evidences point to a key role of genetic variants of the TERT and TERC genes in cancer development. We analyzed the genetic variability of these two gene regions using samples of 2,267 multiple myeloma (MM) cases and 2,796 healthy controls. We found that a TERT variant, rs2242652, is associated with reduced MM susceptibility (OR = 0.81; 95% CI: 0.72-0.92; p = 0.001). In addition we measured the leukocyte telomere length (LTL) in a subgroup of 140 cases who were chemotherapy-free at the time of blood donation and 468 controls, and found that MM patients had longer telomeres compared to controls (OR = 1.19; 95% CI: 0.63-2.24; p(trend)  = 0.01 comparing the quartile with the longest LTL versus the shortest LTL). Our data suggest the hypothesis of decreased disease risk by genetic variants that reduce the efficiency of the telomerase complex. This reduced efficiency leads to shorter telomere ends, which in turn may also be a marker of decreased MM risk.

Inherited genetic susceptibility to multiple myeloma

Although the familial clustering of multiple myeloma (MM) supports the role of inherited susceptibility, only recently has direct evidence for genetic predisposition been demonstrated. A meta-analysis of two genome-wide association (GWA) studies has identified single-nucleotide polymorphisms (SNPs) localising to a number of genomic regions that are robustly associated with MM risk. In this review, we provide an overview of the evidence supporting a genetic contribution to the predisposition to MM and MGUS (monoclonal gammopathy of unknown significance), and the insight this gives into the biological basis of disease aetiology. We also highlight the promise of future approaches to identify further specific risk factors and their potential clinical utility.

A functional polymorphism in the promoter region of the IL1B gene is associated with risk of multiple myeloma

The cytokine interleukin-1β (IL1B) is important for anti-tumour immune response. Genetic variation may modify the expression of IL1B and thereby influence the risk of disease. We investigated genetic variations with functional importance in the IL1B and NFKB1 genes in 348 population-based samples of multiple myeloma (MM) and a random sample of 1700 individuals. Carriers of the variant T-allele IL1B C-3737T and carriers of the TGT haplotype were at lower risk of MM [relative risk (RR) 0·58 (95% confidence interval (CI) = 0·41-0·84) and RR 0·59 (95%CI 0·40-0·85), respectively]. No association with risk of MM was found for the NFKB1- 94 ins/del polymorphism.