Chemotherapy-Related Cardiac Dysfunction: A Systematic Review of Genetic Variants Modulating Individual Risk.
Topic: Radiation/Chemotherapy

Chemotherapy-related cardiac dysfunction is a significant side effect of anticancer treatment. Risk stratification is based on clinical- and treatment-related risk factors that do not adequately explain individual susceptibility. The addition of genetic variants may improve risk assessment. We conducted a systematic literature search in PubMed and Embase, to identify studies investigating genetic risk factors for chemotherapy-related cardiac dysfunction. Included were articles describing genetic variants in humans altering susceptibility to chemotherapy-related cardiac dysfunction. The validity of identified studies was assessed by 10 criteria, including assessment of population stratification, statistical methodology, and replication of findings. We identified 40 studies: 34 exploring genetic risk factors for anthracycline-induced cardiotoxicity (n=9678) and 6 studies related to trastuzumab-associated cardiotoxicity (n=642). The majority (35/40) of studies had a candidate gene approach, whereas 5 genome-wide association studies have been performed. We identified 25 genetic variants in 20 genes and 2 intergenic variants reported significant at least once. The overall validity of studies was limited, with small cohorts, failure to assess population ancestry and lack of replication. SNPs with the most robust evidence up to this point are 

PICO
Population: Patients undergoing chemotherapy for cancer
Intervention: Genetic variants influencing susceptibility to chemotherapy-related cardiac dysfunction
Comparison: Standard risk assessment without genetic variants
Outcomes: Identification of genetic markers for individual risk assessment of chemotherapy-related cardiac dysfunction

Included studies:
title: Role of the HER2 [Ile655Val] genetic polymorphism in tumorogenesis and in the risk of trastuzumab-related cardiotoxicity.
abstract: To examine the impact of a frequent her2 gene polymorphism (Ile655Val) on tumor growth and on the pharmacodynamics of treatment by trastuzumab.
title: The relationship between changes in functional cardiac parameters following anthracycline therapy and carbonyl reductase 3 and glutathione S transferase Pi polymorphisms.
abstract: The aim of this prospective clinical study is to evaluate the relationship between changes in functional cardiac parameters following anthracycline therapy and carbonyl reductase 3 (CBR3p.V244M) and glutathione S transferase Pi (GSTP1p.I105V) polymorphisms. Seventy patients with normal cardiac function and no history of cardiac disease scheduled to undergo anthracycline chemotherapy were included in the study. The patients' cardiac function was evaluated by gated blood pool scintigraphy and echocardiography before and after chemotherapy, as well as 1 year following therapy. Gene polymorphisms were genotyped in 70 patients using TaqMan probes, validated by DNA sequencing. A deteriorating trend was observed in both systolic and diastolic parameters from GG to AA in CBR3p.V244M polymorphism. Patients with G-allele carriers of GSTP1p.I105V polymorphism were common (60%), with significantly decreased PFR compared to patiens with AA genotype. Variants of CBR3 and GSTP1 enzymes may be associated with changes in short-term functional cardiac parameters.
title: Clinical and genetic determinants of anthracycline-induced cardiac iron accumulation.
abstract: The involvement of iron in anthracycline cardiotoxicity is supported by extensive experimental data, and by the preventive efficacy of dexrazoxane, an iron chelator. However, no clinical evidence of anthracycline-induced cardiac iron accumulation is available and the influence of previous iron overload or of genetic factors in human-induced heart disease is largely unknown. Our aim was to test the hypothesis that anthracyclines increase iron heart concentration and that HFE genotype modulates this iron deposit.
title: Validation of variants in SLC28A3 and UGT1A6 as genetic markers predictive of anthracycline-induced cardiotoxicity in children.
abstract: The use of anthracyclines as effective antineoplastic drugs is limited by the occurrence of cardiotoxicity. Multiple genetic variants predictive of anthracycline-induced cardiotoxicity (ACT) in children were recently identified. The current study was aimed to assess replication of these findings in an independent cohort of children.
title: Genome-wide association and pathway analysis of left ventricular function after anthracycline exposure in adults.
abstract: Anthracyclines are important chemotherapeutic agents, but their use is limited by cardiotoxicity. Candidate gene and genome-wide studies have identified putative risk loci for overt cardiotoxicity and heart failure, but there has been no comprehensive assessment of genomic variation influencing the intermediate phenotype of anthracycline-related changes in left ventricular (LV) function. The purpose of this study was to identify genetic factors influencing changes in LV function after anthracycline chemotherapy.
title: Cardiac dysfunction in the trastuzumab clinical trials experience.
abstract: This study sought to estimate cardiac dysfunction (CD) risk for patients receiving trastuzumab; to characterize observed CD by severity, treatment, and clinical outcome; to assess effects of baseline clinical risk factors on CD; and to assess effects of cumulative doses of anthracyclines and trastuzumab on CD.
title: Correlation of HER2, FCGR2A, and FCGR3A gene polymorphisms with trastuzumab related cardiac toxicity and efficacy in a subgroup of patients from UNICANCER-PACS 04 trial.
abstract: The purpose of this study was to investigate, in the context of a prospective node-positive-breast cancer trial HER2 containing-regimen (UNICANCER-PACS 04 trial), the predictive value of HER2, FCGRIIA, and FCGRIIIA gene polymorphisms for cardiac toxicity and efficacy of trastuzumab. We analyzed HER2-I655V, FCGR2A-H131R, and FCGR3A-V158F single nucleotide polymorphisms in patients in adjuvant setting treated by six courses of either fluorouracil 500 mg/m(2), epirubicin 100 mg/m(2) and cyclophosphamide 500 mg/m(2), or epirubicin 75 mg/m(2) and docetaxel 75 mg/m(2) every 3 weeks then randomly assigned, in case of HER2 overexpressing tumor, to either trastuzumab for 1 year or nothing. Left ventricular ejection fraction and clinical examination were monitored in each patient, seven times throughout the study to detect congestive heart failure or asymptomatic subclinical cardiac toxicity. All genotypes were analyzed in relation to cardiac toxicity, EFS, and OS. One hundred and thirty-two HER2-positive breast cancer patients were analyzed. The HER2-I655V genotype was significantly associated with cardiac toxicity (p = 0.025). The FCGR2A-131 H/H genotype was significantly correlated with a shorter EFS (p = 0.027). The FCGR3A-158 V/V genotype was not correlated with EFS nor OS. These results might be useful in making a treatment choice of HER2 blockers in adjuvant setting by with an increase in efficacy and decrease in toxicity.
title: Angiotensin II-Receptor Inhibition With Candesartan to Prevent Trastuzumab-Related Cardiotoxic Effects in Patients With Early Breast Cancer: A Randomized Clinical Trial.
abstract: This is the first randomized placebo-controlled evaluation of a medical intervention for the prevention of trastuzumab-related cardiotoxic effects.
title: Early detection of anthracycline cardiotoxicity and improvement with heart failure therapy.
abstract: Three types of anthracycline-induced cardiotoxicities are currently recognized: acute, early-onset chronic, and late-onset chronic. However, data supporting this classification are lacking. We prospectively evaluated incidence, time of occurrence, clinical correlates, and response to heart failure therapy of cardiotoxicity.
title: Clinical and Genetic Determinants of Cardiomyopathy Risk among Hematopoietic Cell Transplantation Survivors.
abstract: Cardiomyopathy has been recognized as a complication after hematopoietic cell transplantation (HCT). Using a nested case-cohort design, we examined the relationships between demographic, therapeutic, and selected cardiovascular disease risk factors among ≥1-year HCT survivors who developed cardiomyopathy before (n = 43) or after (n = 89) 1 year from HCT as compared to a randomly selected subcohort of survivors without cardiomyopathy (n = 444). Genomic data were available for 79 cases and 267 noncases. Clinical and genetic covariates were examined for association with the risk of early or late cardiomyopathy. Clinical risk factors associated with both early- and late-onset cardiomyopathy included anthracycline exposure ≥250 mg/m(2) and pre-existing hypertension. Among late-onset cardiomyopathy cases, the development of diabetes and ischemic heart disease further increased risk. We replicated several previously reported genetic associations among early-onset cardiomyopathy cases, including rs1786814 in CELF4, rs2232228 in HAS3, and rs17863783 in UGT1A6. None of these markers were associated with risk of late-onset cardiomyopathy. A combination of demographic, treatment, and clinical covariates predicted early-onset cardiomyopathy with reasonable accuracy (area under the curve [AUC], .76; 95% confidence interval [CI], .68 to .83), but prediction of late cardiomyopathy was poor (AUC, .59; 95% CI .53 to .67). The addition of genetic polymorphisms with marginal associations (odds ratios ≥1.3) did not enhance prediction for either early- or late-onset cardiomyopathy. Conventional cardiovascular risk factors influence the risk of both early- and late-onset cardiomyopathy in HCT survivors. Although certain genetic markers may influence the risk of early-onset disease, further work is required to validate previously reported findings and to determine how genetic information should be incorporated into clinically useful risk prediction models.
title: Genome-Wide Association Study for Anthracycline-Induced Congestive Heart Failure.
abstract: Anthracycline-induced congestive heart failure (CHF) is a rare but serious toxicity associated with this commonly employed anticancer therapy. The ability to predict which patients might be at increased risk prior to exposure would be valuable to optimally counsel risk-to-benefit ratio for each patient. Herein, we present a genome-wide approach for biomarker discovery with two validation cohorts to predict CHF from adult patients planning to receive anthracycline.