Genetic and Modifiable Risk Factors Contributing to Cisplatin-Induced Toxicities

Effective administration of traditional cytotoxic chemotherapy is often limited by off-target toxicities. This clinical dilemma is epitomized by cisplatin, a platinating agent that has potent antineoplastic activity due to its affinity for DNA and other intracellular nucleophiles. Despite its efficacy against many adult-onset and pediatric malignancies, cisplatin elicits multiple off-target toxicities that can not only severely impact a patient’s quality of life, but also lead to dose reductions or the selection of alternative therapies that can ultimately affect outcomes. Without an effective therapeutic measure by which to successfully mitigate many of these symptoms, there have been attempts to identify a priori those individuals who are more susceptible to developing these sequelae through studies of genetic and nongenetic risk factors. Older age is associated with cisplatin induced ototoxicity, neurotoxicity and nephrotoxicity. Traditional genome-wide association studies have identified single nucleotide polymorphisms in ACYP2 and WFS1 associated with cisplatin-induced hearing loss. However, validating associations between specific genotypes and cisplatin-induced toxicities with enough stringency to warrant clinical application remains challenging. This review summarizes the current state of knowledge with regard to specific adverse sequelae following cisplatin-based therapy with a focus on ototoxicity, neurotoxicity, nephrotoxicity, myelosuppression and nausea/emesis. We discuss variables (genetic and nongenetic) contributing to these detrimental toxicities, and currently available means to prevent or treat their occurrence

Cisplatin, environmental metals, and cardiovascular disease: an urgent need to understand underlying mechanisms

Significantly increased risks of cardiovascular disease occur in testicular cancer survivors given cisplatin-based chemotherapy. The postulated mechanism of platinum-based chemotherapy's vascular toxicity has been thought secondary to its different early- and late- effects on vascular injury, endothelial dysfunction, and induction of a hypercoagulable state. We highlight for the first time the similarities between platinum-associated vascular adverse events and the vascular toxicity associated with other xenobiotic-metal contaminants. The vascular toxicity seen in large epidemiologic studies of testicular cancer survivors may in part be similar and mechanistically linked to the risk seen in environmental heavy metal contaminants linked to cardiovascular disease. Future research should be directed to better understand the magnitude of the adverse cardiovascular effects of platinum and to elucidate the underlying mechanisms of action

Adverse Health Outcomes among U.S. Testicular Cancer Survivors after Cisplatin-Based Chemotherapy vs. Surgical Management

We evaluated for the first time adverse health outcomes (AHOs) among U.S. testicular cancer survivors (TCS) given chemotherapy (n = 381) vs. surgery-only patients (n = 98) managed at a single institution, accounting for non-treatment-related risk factors to delineate chemotherapy’s impact. Chemotherapy consisted largely of bleomycin-etoposide-cisplatin (BEP) administered in 3 or 4 cycles (BEPX3, n = 235; BEPX4, n = 82). Incidence of ≥ 3 AHOs was lowest in surgery-only TCS and increased with BEPX3, BEPX4 and other cisplatin-based regimens (12.2%, 40.8%, 52.5%, 54.8%; P<0.0001). Multivariate modeling assessed associations of risk factors and treatment with hearing impairment, tinnitus, peripheral neuropathy, and Raynaud phenomenon. Risk for each AHO significantly increased with both increasing chemotherapy burden (P < 0.0001) and selected modifiable risk factors (P < 0.05): hypertension (OR = 2.40) and noise exposure (OR ≥ 2.3) for hearing impairment; noise exposure for tinnitus (OR ≥ 1.69); peripheral vascular disease for neuropathy (OR = 8.72), and current smoking for Raynaud phenomenon (OR = 2.41). Clinicians should manage modifiable risk factors for AHOs among TCS

Cumulative Burden of Morbidity Among Testicular Cancer Survivors After Standard Cisplatin-Based Chemotherapy: A Multi-Institutional Study

Purpose In this multicenter study, we evaluated the cumulative burden of morbidity (CBM) among > 1,200 testicular cancer survivors and applied factor analysis to determine the co-occurrence of adverse health outcomes (AHOs). Patients and Methods Participants were ≤ 55 years of age at diagnosis, finished first-line chemotherapy ≥ 1 year previously, completed a comprehensive questionnaire, and underwent physical examination. Treatment data were abstracted from medical records. A CBM score encompassed the number and severity of AHOs, with ordinal logistic regression used to assess associations with exposures. Nonlinear factor analysis and the nonparametric dimensionality evaluation to enumerate contributing traits procedure determined which AHOs co-occurred. Results Among 1,214 participants, approximately 20% had a high (15%) or very high/severe (4.1%) CBM score, whereas approximately 80% scored medium (30%) or low/very low (47%). Increased risks of higher scores were associated with four cycles of either ifosfamide, etoposide, and cisplatin (odds ratio [OR], 1.96; 95% CI, 1.04 to 3.71) or bleomycin, etoposide, and cisplatin (OR, 1.44; 95% CI, 1.04 to 1.98), older attained age (OR, 1.18; 95% CI, 1.10 to 1.26), current disability leave (OR, 3.53; 95% CI, 1.57 to 7.95), less than a college education (OR, 1.44; 95% CI, 1.11 to 1.87), and current or former smoking (OR, 1.28; 95% CI, 1.02 to 1.63). CBM score did not differ after either chemotherapy regimen ( P = .36). Asian race (OR, 0.41; 95% CI, 0.23 to 0.72) and vigorous exercise (OR, 0.68; 95% CI, 0.52 to 0.89) were protective. Variable clustering analyses identified six significant AHO clusters (χ2 P < .001): hearing loss/damage, tinnitus (OR, 16.3); hyperlipidemia, hypertension, diabetes (OR, 9.8); neuropathy, pain, Raynaud phenomenon (OR, 5.5); cardiovascular and related conditions (OR, 5.0); thyroid disease, erectile dysfunction (OR, 4.2); and depression/anxiety, hypogonadism (OR, 2.8). Conclusion Factors associated with higher CBM may identify testicular cancer survivors in need of closer monitoring. If confirmed, identified AHO clusters could guide the development of survivorship care strategies

Multi-Institutional Assessment of Adverse Health Outcomes Among North American Testicular Cancer Survivors After Modern Cisplatin-Based Chemotherapy

Purpose To provide new information on adverse health outcomes (AHOs) in testicular cancer survivors (TCSs) after four cycles of etoposide and cisplatin (EPX4) or three or four cycles of bleomycin, etoposide, cisplatin (BEPX3/BEPX4). Methods Nine hundred fifty-two TCSs > 1 year postchemotherapy underwent physical examination and completed a questionnaire. Multinomial logistic regression estimated AHOs odds ratios (ORs) in relation to age, cumulative cisplatin and/or bleomycin dose, time since chemotherapy, sociodemographic factors, and health behaviors. Results Median age at evaluation was 37 years; median time since chemotherapy was 4.3 years. Chemotherapy consisted largely of BEPX3 (38.2%), EPX4 (30.9%), and BEPX4 (17.9%). None, one to two, three to four, or five or more AHOs were reported by 20.4%, 42.0%, 25.1%, and 12.5% of TCSs, respectively. Median number after EPX4 or BEPX3 was two (range, zero to nine and zero to 11, respectively; P > .05) and two (range, zero to 10) after BEPX4. When comparing individual AHOs for EPX4 versus BEPX3, Raynaud phenomenon (11.6% v 21.4%; P < .01), peripheral neuropathy (29.2% v 21.4%; P = .02), and obesity (25.5% v 33.0%; P = .04) differed. Larger cumulative bleomycin doses (OR, 1.44 per 90,000 IU) were significantly associated with five or more AHOs. Increasing age was a significant risk factor for one to two, three to four, or five or more AHOs versus zero AHOs (OR, 1.22, 1.50, and 1.87 per 5 years, respectively; P < .01); vigorous physical activity was protective (OR, 0.62, 0.51, and 0.41, respectively; P < .05). Significant risk factors for three to four and five or more AHOs included current (OR, 3.05 and 3.73) or former (OR, 1.61 and 1.76) smoking (P < .05). Self-reported health was excellent/very good in 59.9% of TCSs but decreased as AHOs increased (P < .001). Conclusion Numbers of AHOs after EPX4 or BEPX3 appear similar, with median follow-up of 4.3 years. A healthy lifestyle was associated with reduced number of AHOs

Clinical and Genetic Risk Factors for Adverse Metabolic Outcomes in North American Testicular Cancer Survivors

Background: Testicular cancer survivors (TCS) are at significantly increased risk for cardiovascular disease (CVD), with metabolic syndrome (MetS) an established risk factor. No study has addressed clinical and genetic MetS risk factors in North American TCS. Patients and Methods: TCS were aged <55 years at diagnosis and received first-line chemotherapy. Patients underwent physical examination, and had lipid panels, testosterone, and soluble cell adhesion molecule-1 (sICAM-1) evaluated. A single nucleotide polymorphism in rs523349 (5-α-reductase gene, SRD5A2), recently implicated in MetS risk, was genotyped. Using standard criteria, MetS was defined as ≥3 of the following: hypertension, abdominal obesity, hypertriglyceridemia, decreased high-density lipoprotein (HDL) cholesterol level, and diabetes. Matched controls were derived from the National Health and Nutrition Examination Survey. Results: We evaluated 486 TCS (median age, 38.1 years). TCS had a higher prevalence of hypertension versus controls (43.2% vs 30.7%; P<.001) but were less likely to have decreased HDL levels (23.7% vs 34.8%; P<.001) or abdominal obesity (28.2% vs 40.1%; P<.001). Overall MetS frequency was similar in TCS and controls (21.0% vs 22.4%; P=.59), did not differ by treatment (P=.20), and was not related to rs523349 (P=.61). For other CVD risk factors, TCS were significantly more likely to have elevated low-density lipoprotein (LDL) cholesterol levels (17.7% vs 9.3%; P<.001), total cholesterol levels (26.3% vs 11.1%; P<.001), and body mass index ≥25 kg/m2 (75.1% vs 69.1%; P=.04). On multivariate analysis, age at evaluation (P<.001), testosterone level ≤3.0 ng/mL (odds ratio [OR], 2.06; P=.005), and elevated sICAM-1 level (ORhighest vs lowest quartile, 3.58; P=.001) were significantly associated with MetS. Conclusions and Recommendations: Metabolic abnormalities in TCS are characterized by hypertension and increased LDL and total cholesterol levels but lower rates of decreased HDL levels and abdominal obesity, signifying possible shifts in fat distribution and fat metabolism. These changes are accompanied by hypogonadism and inflammation. TCS have a high prevalence of CVD risk factors that may not be entirely captured by standard MetS criteria. Cancer treatment–associated MetS requires further characterization

Clinical and Genome-Wide Analysis of Serum Platinum Levels after Cisplatin-Based Chemotherapy

Purpose: Serum platinum is measurable for years after completion of cisplatin-based chemotherapy (CBC). We report the largest investigation of serum platinum levels to date of 1,010 testicular cancer survivors (TCS) assessed 1-35 years after CBC and evaluate genetic contributions to these levels. Experimental Design: Eligible TCS given 300 or 400 (±15) mg/m2 cisplatin underwent extensive audiometric testing, clinical examination, completed questionnaires and had crude serum platinum levels measured. Associations between serum platinum and various risk factors and toxicities were assessed after fitting a bi-exponential model adjusted for follow-up time and cumulative cisplatin dose. A genome-wide association study (GWAS) was performed using the serum platinum residuals of the dose and time-adjusted model. Results: Serum platinum levels exceeded the reference range for approximately 31 years, with a strong inverse relationship with creatinine clearance at follow-up (age-adjusted p = 2.13×10−3). We observed a significant, positive association between residual platinum values and luteinizing hormone (age-adjusted p=6.58×10−3). Patients with high residual platinum levels experienced greater Raynaud’s phenomenon than those with medium or low levels (age-adjusted ORhigh/low = 1.46; p = 0.04), as well as a higher likelihood of developing tinnitus (age-adjusted ORhigh/low = 1.68, p = 0.07). GWAS identified one single nucleotide polymorphism (SNP) meeting genome-wide significance rs1377817 (p=4.6×10−8, a SNP intronic to MYH14). Conclusions: This study indicates that residual platinum values are correlated with several cisplatin-related toxicities. One genetic variant is associated with these levels

Adverse Health Outcomes in Relationship to Hypogonadism After Chemotherapy: A Multicenter Study of Testicular Cancer Survivors

Background: This study examined the prevalence of hypogonadism, its clinical and genetic risk factors, and its relationship to adverse health outcomes (AHOs) in North American testicular cancer survivors (TCS) after modern platinum-based chemotherapy. Patients and Methods: Eligible TCS were <55 years of age at diagnosis and treated with first-line platinum-based chemotherapy. Participants underwent physical examinations and completed questionnaires regarding 15 AHOs and health behaviors. Hypogonadism was defined as serum testosterone levels ≤3.0 ng/mL or use of testosterone replacement therapy. We investigated the role of 2 single nucleotide polymorphisms (rs6258 and rs12150660) in the sex hormone-binding globulin (SHBG) locus implicated in increased hypogonadism risk in the general population. Results: Of 491 TCS (median age at assessment, 38.2 years; range, 18.7–68.4 years), 38.5% had hypogonadism. Multivariable binary logistic regression analysis identified hypogonadism risk factors, including age at clinical evaluation (odds ratio [OR], 1.42 per 10-year increase; P=.006) and body mass index of 25 to <30 kg/m2 (OR, 2.08; P=.011) or ≥30 kg/m2 (OR, 2.36; P=.005) compared with <25 kg/m2. TCS with ≥2 risk alleles for the SHBG SNPs had a marginally significant increased hypogonadism risk (OR, 1.45; P=.09). Vigorous-intensity physical activity appeared protective (OR, 0.66; P=.07). Type of cisplatin-based chemotherapy regimen and socioeconomic factors did not correlate with hypogonadism. Compared with TCS without hypogonadism, those with hypogonadism were more likely to report ≥2 AHOs (65% vs 51%; P=.003), to take medications for hypercholesterolemia (20.1% vs 6.0%; P<.001) or hypertension (18.5% vs 10.6%; P=.013), and to report erectile dysfunction (19.6% vs 11.9%; P=.018) or peripheral neuropathy (30.7% vs 22.5%; P=.041). A marginally significant trend for increased use of prescription medications for either diabetes (5.8% vs 2.6%; P=.07) or anxiety/depression (14.8% vs 9.3%; P=.06) was observed. Conclusions: At a relatively young median age, more than one-third of TCS have hypogonadism, which is significantly associated with increased cardiovascular disease risk factors, and erectile dysfunction. Providers should screen TCS for hypogonadism and treat symptomatic patients

Comprehensive Audiometric Analysis of Hearing Impairment and Tinnitus After Cisplatin-Based Chemotherapy in Survivors of Adult-Onset Cancer.

PURPOSE: Cisplatin is widely used but highly ototoxic. Effects of cumulative cisplatin dose on hearing loss have not been comprehensively evaluated in survivors of adult-onset cancer. PATIENTS AND METHODS: Comprehensive audiological measures were conducted on 488 North American male germ cell tumor (GCT) survivors in relation to cumulative cisplatin dose, including audiograms (0.25 to 12 kHz), tests of middle ear function, and tinnitus. American Speech-Language-Hearing Association criteria defined hearing loss severity. The geometric mean of hearing thresholds (0.25 to 12 kHz) summarized overall hearing status consistent with audiometric guidelines. Patients were sorted into quartiles of hearing thresholds of age- and sex-matched controls. RESULTS: Increasing cumulative cisplatin dose (median, 400 mg/m(2); range, 200 to 800 mg/m(2)) was significantly related to hearing loss at 4, 6, 8, 10, and 12 kHz (P trends, .021 to \u3c .001): every 100 mg/m(2) increase resulted in a 3.2-dB impairment in age-adjusted overall hearing threshold (4 to 12 kHz; P \u3c .001). Cumulative cisplatin doses \u3e 300 mg/m(2) were associated with greater American Speech-Language-Hearing Association-defined hearing loss severity (odds ratio, 1.59; P = .0066) and worse normative-matched quartiles (odds ratio, 1.33; P = .093) compared with smaller doses. Almost one in five (18%) patients had severe to profound hearing loss. Tinnitus (40% patients) was significantly correlated with reduced hearing at each frequency (P \u3c .001). Noise-induced damage (10% patients) was unaffected by cisplatin dose (P = .59). Hypertension was significantly related (P = .0066) to overall hearing threshold (4 to 12 kHz) in age- and cisplatin dose-adjusted analyses. Middle ear deficits occurred in 22.3% of patients but, as expected, were not related to cytotoxic drug dosage. CONCLUSION: Follow-up of adult-onset cancer survivors given cisplatin should include routine inquiry for hearing status and tinnitus, referral to audiologists as clinically indicated, and hypertension control. Patients should be urged to avoid noise exposure, ototoxic drugs, and other factors that further damage hearing

Clinical and Genome-wide Analysis of Cisplatin-induced Tinnitus Implicates Novel Ototoxic Mechanisms

Cisplatin, a commonly used chemotherapeutic, results in tinnitus, the phantom perception of sound. Our purpose was to identify the clinical and genetic determinants of tinnitus among testicular cancer survivors (TCS) following cisplatin-based chemotherapy. Experimental Design: TCS (n= 762) were dichotomized to cases (moderate/severe tinnitus; n=154) and controls (none; n=608). Logistic regression was used to evaluate associations with comorbidities and SNP dosages in GWAS following quality control and imputation (covariates: age, noise exposure, cisplatin dose, genetic principal components). Pathway over-representation tests and functional studies in mouse auditory cells were performed. Results: Cisplatin-induced tinnitus (CisIT) significantly associated with age at diagnosis (P=0.007) and cumulative cisplatin dose (P=0.007). CisIT prevalence was not significantly greater in 400 mg/m2-treated TCS compared to 300 (P=0.41), but doses >400 mg/m2 (median 580, range 402–828) increased risk by 2.61-fold (P<0.0001). CisIT cases had worse hearing at each frequency (0.25–12 kHz, P<0.0001), and reported more vertigo (OR=6.47; P<0.0001) and problems hearing in a crowd (OR=8.22; P<0.0001) than controls. Cases reported poorer health (P=0.0005) and greater psychotropic medication use (OR=2.4; P=0.003). GWAS suggested a variant near OTOS (rs7606353, P=2×10−6) and OTOS eQTLs were significantly enriched independently of that SNP (P=0.018). OTOS overexpression in HEI-OC1, a mouse auditory cell line, resulted in resistance to cisplatin-induced cytotoxicity. Pathway analysis implicated potassium ion transport (q=0.007). Conclusions: CisIT associated with several neuro-otological symptoms, increased use of psychotropic medication, and poorer health. OTOS, expressed in the cochlear lateral wall, was implicated as protective. Future studies should investigate otoprotective targets in supporting cochlear cells