Assessing Heterogeneity of Treatment Effect in Real-World Data

Increasing availability of real-world data (RWD) generated from patient care enables the generation of evidence to inform clinical decisions for subpopulations of patients and perhaps even individuals. There is growing opportunity to identify important heterogeneity of treatment effects (HTE) in these subgroups. Thus, HTE is relevant to all with interest in patients' responses to interventions, including regulators who must make decisions about products when signals of harms arise postapproval and payers who make coverage decisions based on expected net benefit to their beneficiaries. Prior work discussed HTE in randomized studies. Here, we address methodological considerations when investigating HTE in observational studies. We propose 4 primary goals of HTE analyses and the corresponding approaches in the context of RWD: to confirm subgroup effects, to describe the magnitude of HTE, to discover clinically important subgroups, and to predict individual effects. We discuss other possible goals including exploring prognostic score- and propensity score-based treatment effects, and testing the transportability of trial results to populations different from trial participants. Finally, we outline methodological needs for enhancing real-world HTE analysis.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants Versus Warfarin Among Adults With Cancer and Atrial Fibrillation

BACKGROUND

While clinical guidelines recommend direct-acting oral anticoagulants (DOAC) over warfarin to treat isolated nonvalvular atrial fibrillation, guidelines are silent regarding nonvalvular atrial fibrillation treatment among individuals with cancer, reflecting the paucity of evidence in this setting. We quantified relative risk of ischemic stroke or systemic embolism and major bleeding (primary outcomes), and all-cause and cardiovascular death (secondary outcomes) among older individuals with cancer and nonvalvular atrial fibrillation comparing DOACs and warfarin.

METHODS

This retrospective cohort study used Surveillance, Epidemiology, and End Results cancer registry and linked US Medicare data from 2010 through 2016, and included individuals diagnosed with cancer and nonvalvular atrial fibrillation who newly initiated DOAC or warfarin. We used inverse probability of treatment weighting to control confounding. We used competing risk regression for primary outcomes and cardiovascular death, and Cox proportional hazard regression for all-cause death.

RESULTS

Among 7675 individuals included in the cohort, 4244 (55.3%) received DOACs and 3431 (44.7%) warfarin. In the inverse probability of treatment weighting analysis, there was no statistically significant difference among DOAC and warfarin users in the risk of ischemic stroke or systemic embolism (1.24 versus 1.19 events per 100 person-years, adjusted hazard ratio 1.41 [95% CI, 0.92-2.14]), major bleeding (3.08 versus 4.49 events per 100 person-years, adjusted hazard ratio 0.90 [95% CI, 0.70-1.17]), and cardiovascular death (1.88 versus 3.14 per 100 person-years, adjusted hazard ratio 0.82 [95% CI, 0.59-0.1.13]). DOAC users had significantly lower risk of all-cause death (7.09 versus 13.3 per 100 person-years, adjusted hazard ratio 0.81 [95% CI, 0.69-0.94]) compared to warfarin users.

CONCLUSIONS

Older adults with cancer and atrial fibrillation exposed to DOACs had similar risks of stroke and systemic embolism and major bleeding as those exposed to warfarin. Relative to warfarin, DOAC use was associated with a similar risk of cardiovascular death and a lower risk of all-cause death.

Safety and effectiveness of apixaban versus warfarin for acute venous thromboembolism in patients with end-stage kidney disease: A national cohort study

BACKGROUND

Patients with end-stage kidney disease (ESKD) are at significantly increased risk for both thrombosis and bleeding relative to those with normal renal function. The optimal therapy of venous thromboembolism (VTE) in patients with ESKD is unknown.

OBJECTIVE

To compare the safety and effectiveness of apixaban relative to warfarin in patients with ESKD and acute VTE.

DESIGN, SETTING AND PARTICIPANTS

New-user, active-comparator retrospective United States population-based cohort with inverse probability of treatment weighting, using the United States Renal Data System data from 2014 to 2018. We included adults with ESKD on hemodialysis or peritoneal dialysis who were newly initiated on apixaban or warfarin for an acute VTE.

MAIN OUTCOME AND MEASURES

The coprimary outcomes were major bleeding, recurrent VTE, and all-cause mortality within 6 months of anticoagulant initiation. Secondary outcomes were intracranial hemorrhage and gastrointestinal bleeding. The primary analyses were based on intent-to-treat defined by the first drug received and accounted for competing risks of death. Sensitivity analyses included varied follow-up time, as-treated analyses, and dose-specific apixaban subgroups.

RESULTS

The apixaban and warfarin cohorts included 2302 and 9263 patients, respectively. Apixaban was associated with a lower risk of major bleeding (hazard ratio [HR] 0.81, 95% confidence interval [CI]: 0.70-0.94), intracranial bleeding (HR 0.69, 95% CI 0.48-0.98), and gastrointestinal bleeding (HR 0.82, 95% CI 0.69-0.96). Recurrent VTE and all-cause mortality were not significantly different between the groups.

CONCLUSION

Apixaban was associated with a lower risk of bleeding relative to warfarin when used to treat acute VTE in patients with ESKD on dialysis.

Associations of Nutritional, Environmental, and Metabolic Biomarkers with Diabetes-Related Mortality in U.S. Adults: The Third National Health and Nutrition Examination Surveys between 1988-1994 and 2016

Background: Nutritional, environmental, and metabolic status may play a role in affecting the progression and prognosis of type 2 diabetes. However, results in identifying prognostic biomarkers among diabetic patients have been inconsistent and inconclusive. We aimed to evaluate the associations of nutritional, environmental, and metabolic status with disease progression and prognosis among diabetic patients. Methods: In a nationally representative sample in the NHANES III (The Third National Health and Nutrition Examination Survey, 1988−1994), we analyzed available data on 44 biomarkers among 2113 diabetic patients aged 20 to 90 years (mean age: 58.2 years) with mortality data followed up through 2016. A panel of 44 biomarkers from blood and urine specimens available from NHANES III were included in this study and the main outcomes as well as the measures are mortalities from all-causes. We performed weighted logistic regression analyses after controlling potential confounders. To assess incremental prognostic values of promising biomarkers beyond traditional risk factors, we compared c-statistics of the adjusted models with and without biomarkers, separately. Results: In total, 1387 (65.2%) deaths were documented between 1988 and 2016. We observed an increased risk of all-cause mortality associated with higher levels of serum C-reactive protein (p for trend = 0.0004), thyroid stimulating hormone (p for trend = 0.04), lactate dehydrogenase (p for trend = 0.02), gamma glutamyl transferase (p for trend = 0.02), and plasma fibrinogen (p for trend = 0.03), and urine albumin (p for trend < 0.0001). In contrast, higher levels of serum sodium (p for trend = 0.005), alpha carotene (p for trend = 0.006), and albumin (p for trend = 0.005) were associated with a decreased risk of all-cause mortality. In addition, these significant associations were not modified by age, sex, or race. Inclusion of thyroid stimulating hormone (p = 0.03), fibrinogen (p = 0.01), and urine albumin (p < 0.0001), separately, modestly improved the discriminatory ability for predicting all-cause mortality among diabetic patients. Conclusions: Our nationwide study findings provide strong evidence that some nutritional, environmental, and metabolic biomarkers were significant predictors of all-cause mortality among diabetic patients and may have potential clinical value for improving stratification of mortality risk.

Use of oral anticoagulants among individuals with cancer and atrial fibrillation in the United States, 2010-2016

Background

Anticoagulation among patients with cancer and atrial fibrillation is challenging due to elevated risk of bleeding and stroke. We characterized use of oral anticoagulants among patients with cancer and non‐valvular atrial fibrillation (NVAF).

Methods

We used Surveillance, Epidemiology, and End Results (SEER)‐Medicare data and included patients with cancer aged ≥66 years with an incident diagnosis of NVAF from 2010 to 2016. We used a Cox proportional hazard model and multivariable logistic regression to identify factors associated with anticoagulant use versus no use and direct oral anticoagulants (DOACs) versus warfarin use, respectively.

Results

Of 27,702 patients with cancer and NVAF, 4469 (16.1%) used DOACs and 3577 (12.9%) used warfarin. Among 8046 anticoagulant users, DOACs use increased from 21.8% in 2011 to 76.2% in 2016, with a corresponding decline in warfarin use from 78.2% to 23.8%. Nearly 7 out of 10 patients with cancer and NVAF did not initiate anticoagulation in 2016. Anticoagulant use was more likely among those with higher CHA₂DS₂‐VASc scores (hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.27–1.90 for score ≥6 vs. 1) or with lower HAS‐BLED scores (HR 1.96, 95% CI 1.67–2.30 for score 1 vs. ≥6). Among anticoagulant users, DOAC use was less likely than warfarin in those with higher CHA₂DS₂‐VASc scores (odds ratio [OR] 0.53, 95% CI 0.33–0.84 for score ≥6 vs. 1).

Conclusions

Nearly 7 out of 10 patients with cancer and NVAF did not receive anticoagulation. Use of DOACs increased from 2010 to 2016, with a corresponding decline in warfarin use. DOACs are used less than warfarin among those at higher risk of stroke.

Ototoxicity After Cisplatin-Based Chemotherapy: Factors Associated With Discrepancies Between Patient-Reported Outcomes and Audiometric Assessments

OBJECTIVES

To provide new information on factors associated with discrepancies between patient-reported and audiometrically defined hearing loss (HL) in adult-onset cancer survivors after cisplatin-based chemotherapy (CBCT) and to comprehensively investigate risk factors associated with audiometrically defined HL.

DESIGN

A total of 1410 testicular cancer survivors (TCS) ≥6 months post-CBCT underwent comprehensive audiometric assessments (0.25 to 12 kHz) and completed questionnaires. HL severity was defined using American Speech-Language-Hearing Association criteria. Multivariable multinomial regression identified factors associated with discrepancies between patient-reported and audiometrically defined HL and multivariable ordinal regression evaluated factors associated with the latter.

RESULTS

Overall, 34.8% of TCS self-reported HL. Among TCS without tinnitus, those with audiometrically defined HL at only extended high frequencies (EHFs) (10 to 12 kHz) (17.8%) or at both EHFs and standard frequencies (0.25 to 8 kHz) (23.4%) were significantly more likely to self-report HL than those with no audiometrically defined HL (8.1%) [odds ratio (OR) = 2.48; 95% confidence interval (CI), 1.31 to 4.68; and OR = 3.49; 95% CI, 1.89 to 6.44, respectively]. Older age (OR = 1.09; 95% CI, 1.07 to 1.11, p < 0.0001), absence of prior noise exposure (OR = 1.40; 95% CI, 1.06 to 1.84, p = 0.02), mixed/conductive HL (OR = 2.01; 95% CI, 1.34 to 3.02, p = 0.0007), no hearing aid use (OR = 5.64; 95% CI, 1.84 to 17.32, p = 0.003), and lower education (OR = 2.12; 95% CI, 1.23 to 3.67, p = 0.007 for high school or less education versus postgraduate education) were associated with greater underestimation of audiometrically defined HL severity, while tinnitus was associated with greater overestimation (OR = 4.65; 95% CI, 2.64 to 8.20 for a little tinnitus, OR = 5.87; 95% CI, 2.65 to 13.04 for quite a bit tinnitus, and OR = 10.57; 95% CI, 4.91 to 22.79 for very much tinnitus p < 0.0001). Older age (OR = 1.13; 95% CI, 1.12 to 1.15, p < 0.0001), cumulative cisplatin dose (>300 mg/m2, OR = 1.47; 95% CI, 1.21 to 1.80, p = 0.0001), and hypertension (OR = 1.80; 95% CI, 1.28 to 2.52, p = 0.0007) were associated with greater American Speech-Language-Hearing Association-defined HL severity, whereas postgraduate education (OR = 0.58; 95% CI, 0.40 to 0.85, p = 0.005) was associated with less severe HL.

CONCLUSIONS

Discrepancies between patient-reported and audiometrically defined HL after CBCT are due to several factors. For survivors who self-report HL but have normal audiometric findings at standard frequencies, referral to an audiologist for additional testing and inclusion of EHFs in audiometric assessments should be considered.

Hearing loss after cisplatin-based chemotherapy: Patient-reported outcomes versus audiometric assessments

5016

Background: Although pure-tone audiometry is the gold standard to evaluate hearing loss (HL), patient-reported outcomes are practically more time and cost effective. However, no data exist on factors associated with discrepancies between patient-reported and audiometrically-defined HL in adult-onset cancer survivors after cisplatin-based chemotherapy (CBCT); and few comprehensive assessments of factors associated with audiometrically-defined HL have been conducted. Methods: A total of 1,410 testicular cancer survivors (TCS) ≥6 months post-CBCT completed comprehensive audiometric assessments (0.25-12 kHz) and detailed questionnaires of sociodemographic, clinical, and health behaviors. Audiometrically-defined HL severity was defined using American Speech-Language-Hearing Association (ASHA) criteria. Multivariable multinomial logistic regression identified factors associated with discrepancies (overestimation and underestimation vs. concordance), between patient-reported and audiometrically-defined HL and multivariable ordinal logistic regression evaluated factors associated with the HL severity. Results: Overall, 34.8% of TCS self-reported HL, while 77.8% had audiometrically-defined HL. Among TCS without tinnitus, those with audiometrically-defined HL at only extended high frequencies (EHFs) (10-12 kHz) (17.8%) or at both EHFs and standard frequencies (0.25-8 kHz) (23.4%) were significantly more likely to self-report HL than those with no audiometrically-defined HL (8.1%) (OR = 2.48; 95%CI, 1.31-4.68 and OR = 3.49; 95%CL,1.89-6.44, respectively). Older age (OR = 1.09; P< 0.0001), absence of prior noise exposure (OR = 1.40; P= 0.02), and mixed/conductive HL (OR = 2.01; P= 0.0007) were associated with greater underestimation of audiometrically-defined HL severity. Hearing aid use (OR = 0.18; P= 0.003) and higher education ( P= 0.004) were associated with less underestimation of audiometrically-defined HL severity, while tinnitus was associated with greater overestimation ( P< 0.0001). Older age (OR = 1.13; P< 0.0001), cumulative cisplatin dose ( > 300 mg/m2, OR = 1.47; P= 0.0001), and hypertension (OR = 1.80; P= 0.0007) were associated with greater ASHA-defined HL severity, whereas post-graduate education (OR = 0.58; P= 0.005) was associated with less severe HL. Conclusions: Discrepancies between patient-reported and audiometrically-defined HL after CBCT are associated with several factors including age, education, tinnitus, prior noise exposure, use of hearing aids, and conductive HL. Understanding these factors will help clinicians to better interpret self-reported HL as a surrogate for audiometric assessments. For survivors who self-report HL, but have normal audiometric findings at standard frequencies, referral to an audiologist for additional testing and inclusion of EHFs in audiometric assessments, should be considered.

Factors associated with use of medications for anxiety and depression in testicular cancer survivors after cisplatin-based chemotherapy

5025

Background: Cancer survivors are at increased risk of anxiety and depression that can affect health-related quality of life. There is no study to date that has examined the characteristics of testicular cancer survivors (TCS) taking medications for anxiety or depression since pharmacological interventions are typically reserved for more severe cases of these disorders. In this study, we aimed to examine sociodemographic factors, cisplatin-related adverse health outcomes (AHOs), and cumulative burden of morbidity (CBMPt) scores associated with medication use for anxiety and/or depression in TCS. Methods: A total of 1,802 TCS who completed CBCT ≥12 months previously completed validated questionnaires regarding sociodemographic features and cisplatin-related AHOs (hearing impairment, tinnitus, peripheral sensory neuropathy (PSN), kidney disease). Patients were recognized as users of medications for anxiety and/or depression if they used pharmacological classes of these medications and also indicated that the reason for use was for anxiety or depression. Individual AHOs were graded 0-to-4 based on severity according to NCI Common Terminology Criteria for Adverse Events version 4.03. A CBMPt score encompassed the number and severity of cisplatin-related AHOs. Multivariable logistic regression models assessed the relationship of individual AHOs and CBMPt with medication use for anxiety and/or depression. Results: A total of 151 TCS (8.4%) used medications for anxiety and/or depression. Any grade of HL, tinnitus, PSN, and kidney disease were reported by 37.9%, 39.5%, 55.2%, and 2.4% of 1,802 participants, respectively. No cisplatin-related AHO were reported by 511 (28.4%) participants, whereas 622 (34.5%), 334 (18.5%), 287 (15.9%), and 48 (2.7%), respectively, had very low, low, medium, and high CBMPt scores. Higher CBMPt scores were significantly associated with greater medication use for anxiety and/or depression (CBMPt scores of low (OR = 2.96, 95%CI, 1.67-5.24), medium (OR = 3.47, 95%CI, 1.95-6.18), and high (OR = 3.18, 95%CI, 1.22-8.3). A multivariable model including individual AHOs indicated that tinnitus ( P= 0.0009), PSN ( P= 0.02), and having health insurance (OR = 2.15, 95%CI, 1.01-4.56) were associated with significantly greater use of these medications; whereas being employed (OR = 0.39, 95%CI, 0.23-0.66) and vigorous physical activity (OR = 0.63, 95%CI,0.44-0.89) were associated with significantly diminished use. Conclusions: We found that TCS with higher CBMPt scores had a higher probability of using medications for anxiety and/or depression and conversely, those who were employed and physically active tended to have reduced use. These findings deserve further investigation in longitudinal studies. In the interim, healthcare providers should be aware of these associations in formulating survivorship care plans.

Impact of cisplatin-related hearing loss (HL) and tinnitus on patient functioning

e23085

Background: Patients given cisplatin-based chemotherapy (CBC) experience HL and tinnitus. However, the impact of these toxicities on psychosocial and physical functioning in cancer survivors has not been systematically evaluated. Methods: Eligible testicular cancer survivors (TCS) aged ≤ 55 y at diagnosis and given first-line CBC at Indiana U., completed comprehensive questionnaires. The validated 25-item Hearing Handicap Inventory for Adults (HHIA) quantified emotional (13 items) and social difficulties (12 items) related to HL. The validated 20-item Tinnitus Primary Function Questionnaire (TPFQ) assessed domains affected by tinnitus, i.e., concentration, emotion, hearing, sleep (5 items each). For each HHIA scale, TCS were grouped into 3 standard handicap levels: 0–16% (none/minimal), 18-42% (mild/moderate), and 44-100% (significant). Proportions of social vs. emotional handicap were compared with a McNemar’s test. For TPFQ, each scale score is continuous (0: [no interference] to 100% [total interference by tinnitus]) and computed as the mean of 5 items. TPFQ measures were compared by signed-rank tests (P < 0.05 was significant). Results: Of 43 TCS (median age: 35 y, range 20–74 y; median time since chemotherapy completion: 7 y, range 2-27 y), 95% were white, and 70% had at least a college degree. Median cumulative cisplatin dose was 300 (range 200-600 mg/m2). The most commonly administered regimen was bleomycin, etoposide and cisplatin; 23 (53.5%) reported HL, and 25 (58%) had tinnitus. Of TCS with HL, 25% had some degree of related handicap (total HHIA scale: 20% and 5% for mild/moderate and significant handicap, respectively). More TCS had social vs. emotional handicap (33.3% vs. 14.3%, P = 0.13). Tinnitus had significantly greater interference with emotion (median: 14, range 0-84) compared to concentration [(median 6, range 0-41), p = 0.04)], and sleep [(median: 0, range (0-78), p = 0.001)]. Other comparisons were not significant. Conclusions: Cisplatin-related HL has a considerably greater negative impact on social vs. emotional measures, and affected TCS may benefit from hearing aids. TCS experiencing significant issues related to emotion due to tinnitus may benefit from interventions to lessen their impact.

Impact of cisplatin-related adverse health outcomes (AHOs) on employment outcomes and self-reported health (SRH) among testicular cancer survivors (TCS)

e16058

Background: We aim to provide new information on cisplatin-related AHOs and employment status in TCS and evaluate impact on SRH. Methods: 1,815 TCS ³1 year post-chemotherapy underwent physical exam, audiometry, renal function evaluation, and completed questionnaires. Therapy data were obtained from medical records. A cumulative burden of morbidity score (CBMPt) assessed the number and severity of platinum-related AHOs (peripheral sensory neuropathy (PSN), hearing loss, tinnitus, and renal function) with grading per CTCAE v4.03. Multivariable regression assessed relations between CBMPt score, individual AHOs and employment status as well as SRH, adjusting for sociodemographic/clinical factors. Unemployment in TCS was compared with subjects in the Behavioral Risk Factor Surveillance System (BRFSS) of similar age/race/ethnicity. Results: Almost 1 in 10 TCS were either on disability leave (2.4%) or unemployed (6.8%) at a median age of 37 yr (median follow-up: 4 yr). TCS with tinnitus (OR = 3.1, grade 3 vs. 0, P = 0.04), renal dysfunction (OR = 13.5, grade 3 vs. 0, P = 0.01), or pain (OR = 7.2 and 40.9, grade 2 or 3 vs. 0, respectively; P < 0.001 each) had significantly greater odds of disability leave vs. full-time employment after adjusting for sociodemographic/clinical factors; pain was strongly correlated with PSN (Pearson r2= 0.40; P < 0.001). CBMPt score was associated with disability leave (OR = 1.5, P = 0.04), but not with unemployment. A significantly higher percentage of TCS were unemployed vs. BRFSS norms (e.g. 3.6% of TCS age 35-39 vs. 2.0% in BRFSS). PSN (OR = 2.2, grade 3 vs. 0, P = 0.02), self-reported hearing loss (OR = 1.8, grade 2/3 vs. 0, P = 0.04), and pain (OR = 2.8 and 8.5, grade 2 or 3 vs. 0, respectively; P < 0.01 each) were each associated with increased odds of unemployment vs. full-time employment. Cisplatin-related AHOs and pain were associated with significantly worse SRH (P < 0.05). Conclusions: Our findings have new, important implications regarding productivity loss and socioeconomic costs in TCS. Survivorship care strategies should include inquiries about employment status, and every effort made to assist affected TCS in returning to the work force.

Adverse health outcomes in relationship to hypogonadism (HG) after platinum-based chemotherapy: A multicenter study of North American testicular cancer survivors (TCS)

LBA10012

Background: HG affects a substantial percentage of TCS and can contribute to significant morbidity, but few studies have examined the relationship between HG and adverse health outcomes (AHO), taking into account genetic variation. Methods: Eligible TCS were < 55 y at diagnosis and treated with only first line chemotherapy after 1990. TCS underwent physical exams and genotyping, and completed questionnaires regarding 16 AHO and health behaviors. HG was defined as serum testosterone ≤ 3.0 ng/mL or the use of testosterone replacement therapy. Results: We evaluated 491 TCS. Median age at evaluation was 38 y (range 19-68). 38.5% had HG. Two SNPs in the sex-hormone-binding globulin ( SHBG) locus previously implicated in increased HG risk in the general population (Ohlsson et al, PLOS Genetics 2011) displayed effect sizes consistent with prior reports (rs6258, OR = 1.3; rs12150660, OR = 0.79), but were not statistically significant. However, TCS with ≥ 2 risk alleles for the two SNPs in the SHBG locus vs no risk alleles had 2-fold increased risk for HG (OR = 2.2, P = .12). Multivariate analysis identified risk factors for HG including: age (OR = 1.4 per 10 year increase, P = .007), and BMI ≥ 25 kg/m2 (OR = 2.2, P = .003). Vigorous-intensity physical activity appeared protective (OR = 0.6, P = .06). Type of chemotherapy regimen and socioeconomic factors did not correlate with HG. Only 35% of TCS with HG vs 49% of those without HG reported none or 1 AHO ( P = .003). TCS with HG were more likely to take medications for dyslipidemia (20% vs 6%, P < .001), hypertension (19% vs 11%, P = .01), erectile dysfunction (ED) (20% vs 12%, P = .02), diabetes (6% vs 3%, P = .07), or anxiety/depression (15% vs 10%, P = 0.06) compared to TCS with normal levels, and also to have peripheral neuropathy (PN) (31% vs 23%, P = .04). HG status did not correlate with oto- or renal toxicity. Conclusions: Over a third of TCS have HG at a relatively young age. HG was associated with increased cardiovascular disease risk factors, ED, and PN. SHBG polymorphisms appear important in TCS, but our study was underpowered to confirm an association. Providers should screen TCS for HG and treat those who are symptomatic.

Adverse health outcomes in relationship to hypogonadism (HG) after platinum-based chemotherapy: A multicenter study of North American testicular cancer survivors (TCS)

LBA10012

The full, final text of this abstract will be available at abstracts.asco.org at 2:00 PM (EDT) on Friday, June 2, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

Genome-wide association study (GWAS) of chemotherapy-induced Raynaud's phenomenon (RP) to reveal shared pathways with cardiovascular disease (CVD)

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Background: RP is an adverse drug reaction characterized by reduced blood flow to the extremities causing pain and sensations of cold. Few studies have examined the genetic basis for RP, although family studies suggest a heritable component to primary RP. Methods: Eligible testicular cancer survivors (TCS) were < 55 y at diagnosis, treated with first line cisplatin-based chemotherapy, and completed questionnaires. Genotyping with standard quality control and imputation were performed. A case-control RP phenotype was derived from patient-reported outcomes and associations were computed by logistic regression. GWAS used cumulative bleomycin dose and 10 genetic principal components as covariates. Gene set enrichment analysis (GSEA) utilized genes ranked by the most significant GWAS SNP in/within 20 kilobases. A polygenic risk score for CVD derived from four prior independent GWAS (Khera et al. NEJM 2016) was assessed for association with RP. Results: Of 749 patients (median age 38 y, median time since chemotherapy 5 y), 38% reported RP. Bleomycin dose was the most significant predictor of RP (OR100 mg/m2 = 1.25, p < 0.0001). Number of years smoking also correlated with RP (ORyear = 1.05, p = 0.002). Age and hypertension showed no significant correlation with RP. GSEA revealed several significant pathways (FDR q < 0.1), including “ cellular response to VEGF stimulus” (q = 0.05) and “ cardiac muscle cell action potential” (q = 0.09). We hypothesized that RP may share genetic architecture with CVD. Deriving a polygenic risk score from genome-wide significant SNPs in prior CVD GWAS (n = 4260-22,389), we showed nearly significant case-control differences in CVD polygenic risk score (two-tailed t-test, p = 0.053). RP frequency significantly increased with polygenic risk score quartile (OR = 1.19, p = 0.008). Conclusions: Over one third of TCS report RP, with greater frequency among bleomycin-treated patients and smokers. Implicated genetic pathways include ones established in CVD. Although shared genetic risk between chemotherapy-induced RP and CVD may be possible, further investigation is required. Primary RP has been inconsistently linked with CVD.

Clinical, sociodemographic, and behavioral factors associated with cumulative burden of morbidity (CBM) among testicular cancer survivors (TCS) in the Platinum study

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Background: TCS are an important group in which to characterize late effects of cancer and its therapy given their young age at diagnosis and high cure rate. We comprehensively evaluated CBM and identified associated clinical, sociodemographic, and behavioral risk factors among TCS given cisplatin based chemotherapy in a multicenter study. Methods: TCS completed a comprehensive health questionnaire. Responses were grouped into 22 adverse health outcomes (AHO) and graded by severity. A CBM score was calculated based on AHO number and severity, following Geenen et al (JAMA 2007). Multivariable ordinal logistic regression examined the association of clinical, sociodemographic, and behavioral factors with CBM. Variable-based hierarchical clustering identified individual AHOs that co-occurred. Results: Among 1,215 TCS (median age at evaluation 38 y, range 19-68 y; time since chemotherapy 4.6 y), over 20% had a CBM score of high (17%), very high (4%) or severe (0.4%). Most TCS, however, had CBM scores of low (37%), medium (28%), very low (9%) or none (5%). In a multivariable model controlling for time since chemotherapy, older attained age (OR 1.2; 95% CI 1.1 - 1.3), being widowed/divorced/separated (OR 1.8; 95% CI 1.1 - 3.1), having less than college-level education (OR 1.7; 95% CI 1.3 - 2.2), being retired/on disability (OR 2.5; 95% CI 1.2 - 5.3), and receipt of 4 cycles of BEP vs. 4 cycles of EP or 3 cycles of BEP (OR 1.3; 95% CI 1.01 - 1.8) were associated with increased odds of a worse CBM score; vigorous exercise (OR 0.7; 95% CI 0.5 - 0.9) and non-white race (OR 0.6; 95% CI 0.4 - 0.9) were associated with decreased odds. A separate cluster analysis revealed five groups of AHOs: those known to be cisplatin-related (e.g. neuropathy, ototoxicity); metabolic abnormalities (e.g. hypercholesterolemia, diabetes); vascular damage (e.g. stroke); testicular cancer-related (e.g. hypogonadism); and other (e.g. thyroid disease). Conclusions: TCS with factors associated with worse CBM may be candidates for closer monitoring. If confirmed, our cluster analysis showing that groups of conditions tend to co-occur in TCS could provide guidance for survivorship care plans.

Metabolic syndrome (MetS) after platinum-based chemotherapy (CHEM): A multicenter study of North American testicular cancer survivors (TCS)

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Background: Testicular cancer has an excellent prognosis since the introduction of platinum-based CHEM. However, several European studies report an excess of cardiovascular disease (CVD) in TCS. MetS is a cluster of cardiovascular risk factors that doubles CVD risk, with several European series noting a prevalence ranging from 13-39% in TCS. In the first large multi-center North American study of TCS, we examine the prevalence of and potential risk factors for MetS after modern CHEM (NCI R01 CA157823). Methods: Eligible TCS were <50 y at diagnosis and treated with only first line CHEM after 1990. TCS underwent physical exams, completed questionnaires regarding co-morbidities and health behaviors and had lipid panels, testosterone, and serum soluble cell adhesion molecule-1 (sICAM-1) measured. A single nucleotide polymorphism, rs523349 (V89L), in 5-α-reductase gene ( SRD5A2) previously suggested to associate with MetS in TCS was genotyped. MetS was defined as ≥3 of the following: hypertension (HTN), waist circumference ≥102 cm, triglycerides ≥150 mg/dL, HDL ≤40 mg/dL, and diabetes (Alberti et al, Circulation 2009). Controls (1:1) derived from the National Health and Nutrition Examination Survey were matched on age, race, and educational status. Results: We evaluated 486 consecutively enrolled TCS. Median age at evaluation was 38 y (range: 19-68). TCS had higher prevalence of HTN compared to controls (43% vs 31%, P < .01) but lower prevalence of low HDL (24% vs 35%, P < .01) and abdominal obesity (28% vs 40%, P < .01). Prevalence of MetS was comparable (21% TCS; 22% controls, P = .59). In multivariate analysis, age at evaluation (P < .01), serum testosterone <3.0 ng/mL (OR = 2.0, P = .005), and elevated sICAM-1 (OR for quartiles 2, 3, 4 vs lowest quartile: 2.7 (P = .01), 3.1 (P < .01), and 3.6 (P < .01), respectively) significantly correlated with MetS. The variant rs523349 (VL/LL) did not associate with MetS. Conclusions: One in 5 TCS treated with CHEM developed MetS. Providers should screen for MetS, adequately treat hypogonadism, HTN and hyperlipidemia, and encourage TCS to maintain a healthy lifestyle. Significant elevations in sICAM-1 underscore a role for inflammation in MetS.