Abstract 5218: Genome-wide association study of African Americans reveals new susceptibility loci contributing to lung cancer and mechanisms of population-specific etiology

Lung cancer incidence and mortality in the U.S. have substantial ethnic disparities. African Americans of both sexes have the high incidence rate at 56.8 and the highest death rate at 38.1 per 100,000 people from 2015 to 2019. Non-Hispanic black men have the highest incidence at 73.9 and the highest death rate at 56.3 per 100,000 people. While many genome-wide association studies (GWAS) of lung cancer have discovered ~45 putative risk loci, a large proportion of the heritability of lung cancer remains unexplained. To date, most single population-based GWAS have been performed in Europeans while there are a few Asian ancestry-specific genetic studies and two cross-ancestry studies. Non-European GWAS of lung cancer has been underrepresented. Although African Americans have higher lung cancer incidence and poorer lung cancer survival rate, and smoke fewer cigarettes per day compared to Europeans, few comprehensive GWAS of lung cancer in African Americans has been conducted. This study aims to decipher the genetic component of predisposition to lung cancer among African Americans. This study aims to decipher the genetic component of predisposition to lung cancer among African Americans. We conducted an African-ancestry GWAS comprising 2,280 lung cancer cases and 4,301 controls to comprehensively characterize common and low-frequency lung cancer genetic susceptibility loci using HRC imputed lung cancer data. The novel variants in or near VWF on 12p13.31 (OR=1.29, P=6.93 × 10−9) for overall lung cancer and GACAT3 on 2p24.3 (0.65, 1.24 × 10−9), TRIP13 on 5p15.33 (3.49, 1.00 × 10−8), ERC1 on 12p13.33 (4.64, 6.08 × 10−9), LMAN1L (near CYP1A1) on 15q24.1 (4.25, 8.71 × 10−9) for lung squamous cell cancer were identified at a genome-wide significance level. Our GWAS of lung cancer identified five novel genetic susceptibility associations and confirmed several variants on 15q25 and 19q13. Further works are required to elucidate the possible biological mechanisms underlying these associations among lung cancer and histological subtypes in African Americans.

Citation Format: Jinyoung Byun, Younghun Han, Xiangjun Xiao, Christine Lusk, Hoda J. Badr, Rayjean Hung, Ann G. Schwartz, Christopher I. Amos, INTEGRAL Consortium. Genome-wide association study of African Americans reveals new susceptibility loci contributing to lung cancer and mechanisms of population-specific etiology. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5218.

Cross-ancestry genome-wide meta-analysis of 61,047 cases and 947,237 controls identifies new susceptibility loci contributing to lung cancer

To identify new susceptibility loci to lung cancer among diverse populations, we performed cross-ancestry genome-wide association studies in European, East Asian and African populations and discovered five loci that have not been previously reported. We replicated 26 signals and identified 10 new lead associations from previously reported loci. Rare-variant associations tended to be specific to populations, but even common-variant associations influencing smoking behavior, such as those with CHRNA5 and CYP2A6, showed population specificity. Fine-mapping and expression quantitative trait locus colocalization nominated several candidate variants and susceptibility genes such as IRF4 and FUBP1. DNA damage assays of prioritized genes in lung fibroblasts indicated that a subset of these genes, including the pleiotropic gene IRF4, potentially exert effects by promoting endogenous DNA damage.

A simulation study of loss to follow up: The impact on time to event and prevention

e14097

Background: Patient attrition during study follow up is a concern in all clinical trials, although its impact on study results has rarely been assessed. In oncology, in particular, where studies are lengthier and may be extended into longitudinal studies, there is an increased likelihood of loss to follow up (LTFU) (Gill et al., 2018). This creates a heightened need to understand how it affects the trial’s validity. The loss of data from patients who have been LTFU can reduce a study’s precision and power. This imprecision not only impacts the results of the current study but can also affect future research as well as future patient treatment options. Studies have found that participant characteristics differ in individuals LTFU as compared to those who remain in follow up (Childs et al., 2011; Geng et al., 2008; Hochheimer et al., 2016). This further emphasizes how attrition can skew study results and their interpretation and supports the need to minimize patient attrition during follow up in order to reduce bias and generate robust study estimates. Methods: This study assessed the impact of LTFU rates on the study estimates through simulations using SAS software. While all endpoints can be affected by LTFU, this study assessed time-to-event endpoints. Exponential distribution was assumed with varying rates of LTFU. In addition, the work covered suggestions for reducing LTFU. Results: Even for low rates of LTFU, biases are introduced in time-to event endpoints. Conclusions: Researchers should make every effort to minimize the extent of LTFU in the design and of and conduct of their trials.

Genome-wide association study of familial lung cancer

To identify genetic variation associated with lung cancer risk, we performed a genome-wide association analysis of 685 lung cancer cases that had a family history of two or more first or second degree relatives compared with 744 controls without lung cancer that were genotyped on an Illumina Human OmniExpressExome-8v1 array. To ensure robust results, we further evaluated these findings using data from six additional studies that were assembled through the Transdisciplinary Research on Cancer of the Lung Consortium comprising 1993 familial cases and 33 690 controls. We performed a meta-analysis after imputation of all variants using the 1000 Genomes Project Phase 1 (version 3 release date September 2013). Analyses were conducted for 9 327 222 SNPs integrating data from the two sources. A novel variant on chromosome 4p15.31 near the LCORL gene and an imputed rare variant intergenic between CDKN2A and IFNA8 on chromosome 9p21.3 were identified at a genome-wide level of significance for squamous cell carcinomas. Additionally, associations of CHRNA3 and CHRNA5 on chromosome 15q25.1 in sporadic lung cancer were confirmed at a genome-wide level of significance in familial lung cancer. Previously identified variants in or near CHRNA2, BRCA2, CYP2A6 for overall lung cancer, TERT, SECISPB2L and RTEL1 for adenocarcinoma and RAD52 and MHC for squamous carcinoma were significantly associated with lung cancer.

ASPEN: A randomized phase II trial of everolimus versus sunitinib in patients with metastatic non-clear cell renal cell carcinoma

TPS4590

Background: Currently no level 1 evidence exists to guide therapeutic decisions in patients with metastatic non-clear cell renal cell carcinoma. Case series and retrospective analyses suggest that strategies targeting either the VEGF or mTOR/TORC1 pathways have clinical activity in papillary, chromophobe, or poorly differentiated histologic subtypes. Methods: We are conducting an international, randomized phase 2 trial of patients with metastatic non-clear cell RCC; either papillary, chromophobe, or undifferentiated histology; any Motzer risk group; and who have had no prior systemic therapy. All patients contribute tissue to an international biorepository for correlative genomic, genetic, and protein biomarker studies, along with companion longitudinal plasma and urine angiome studies. Patients are randomized to either everolimus or sunitinib (1:1) at FDA approved dosing until progression. The primary endpoint is progression free survival. Trial status: Seventy-three out of a planned 108 subjects have been enrolled at the time of abstract submission: median age 64, 59 white, 10 black, 4 unknown race, and includes 42 papillary and 31 chromophobe/undifferentiated histologies, 49 men and 22 women. Accrual is anticipated to be completed by December 2013. Accrual distribution by country is currently 43 (USA), 27 (UK), and 3 (Canada). The first DSMB meeting was conducted after 40 subjects completed at least 6 months of therapy and concluded that there were no unexpected safety signals and that the study should proceed. Tissue (primary, some metastatic, urine, plasma, whole blood) has been collected on all patients to date through the Duke Center for Human Genetics Biorepository. Clinical trial information: NCT01108445.

Mail versus internet surveys: determinants of method of response preferences among health professionals

The authors evaluated determinants of response to Internet-based surveys in a sample (n = 5600) of Texas healthcare professionals. Participants were given the option of responding by mail or over the Web (response, 66%). Internet respondents were younger (p < .001), had worked fewer years in healthcare (p < .001), and were more likely to be male (p < .001) and to work in a hospital (p = .007). Missing questionnaire items were significantly higher among Web responders with regard to age, sex, race, body mass index, and smoking (p < .001). In the final multivariate logistic regression, only male gender (odds ratio [OR] = 2.09, 95% CI = 1.56-2.80) and younger age remained significantly associated with response over the Internet. Age quartile and responding electronically were inversely associated. Taken together with a priori knowledge of the demographic and professional profile of a study population, these findings can be useful in planning and implementation of surveys among healthcare workers.

Occupational risk factors and asthma among health care professionals

RATIONALE

Recent U.S. data suggest an increased risk of work-related asthma among health care workers, yet only a few specific determinants have been elucidated.

OBJECTIVES

To evaluate associations of asthma prevalence with occupational exposures in a cross-sectional survey of health care professionals.

METHODS

A detailed questionnaire was mailed to a random sample (n=5,600) of all Texas physicians, nurses, respiratory therapists, and occupational therapists with active licenses in 2003. Information on asthma symptoms and nonoccupational asthma risk factors obtained from the questionnaire was linked to occupational exposures derived through an industry-specific job-exposure matrix.

MEASUREMENTS

There were two a priori defined outcomes: (1) physician-diagnosed asthma with onset after entry into health care ("reported asthma") and (2) "bronchial hyperresponsiveness-related symptoms," defined through an 8-item symptom-based predictor.

MAIN RESULTS

Overall response rate was 66%. The final study population consisted of 862 physicians, 941 nurses, 968 occupational therapists, and 879 respiratory therapists (n=3,650). Reported asthma was associated with medical instrument cleaning (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.34-3.67), general cleaning (OR, 2.02; 95% CI, 1.20-3.40), use of powdered latex gloves between 1992 and 2000 (OR, 2.17; 95% CI, 1.27-3.73), and administration of aerosolized medications (OR, 1.72; 95% CI, 1.05-2.83). The risk associated with latex glove use was not apparent after 2000. Bronchial hyperresponsiveness-related symptoms were associated with general cleaning (OR, 1.63; 95% CI, 1.21-2.19), aerosolized medication administration (OR, 1.40; 95% CI, 1.06-1.84), use of adhesives on patients (OR, 1.65; 95% CI, 1.22-2.24), and exposure to a chemical spill (OR, 2.02; 95% CI, 1.28-3.21).

CONCLUSIONS

The contribution of occupational exposures to asthma in health care professionals is not trivial, meriting both implementation of appropriate controls and further study.

Validation of an asthma questionnaire for use in healthcare workers

BACKGROUND

Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group.

AIMS

To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers.

METHODS

An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens.

RESULTS

The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals.

CONCLUSIONS

Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Operational aspects of terminating the doxazosin arm of The Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

The Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized, practice-based trial sponsored by the National Heart, Lung, and Blood Institute (NHLBI). The double-blind, active-controlled component of ALLHAT was designed to determine whether the rate of the primary outcome-a composite of fatal coronary heart disease and nonfatal myocardial infarction-differs between diuretic (chlorthalidone) treatment and each of three other classes of antihypertensive drugs: a calcium antagonist (amlodipine), an angiotensin-converting enzyme inhibitor (lisinopril), and an alpha-adrenergic blocker (doxazosin) in high-risk hypertensive persons ages 55 years and older. In addition, 10,377 ALLHAT participants with mild to moderate hypercholesterolemia were also enrolled in a randomized, open-label trial designed to determine whether lowering serum LDL cholesterol with an HMG CoA reductase inhibitor (pravastatin) will reduce all-cause mortality as compared to a control group receiving "usual care." In January 2000, an independent data review committee recommended discontinuing the doxazosin treatment arm. The NHLBI director promptly accepted the recommendation. This article discusses the steps involved in the orderly closeout of one arm of ALLHAT and the dissemination of trial results. These steps included provisional preparations; the actual decision process; establishing a timetable; forming a transition committee; preparing materials and instructions; informing 65 trial officers and coordinators, 628 active clinics and satellite locations, 313 institutional review boards, over 42,000 patients, and the general public; reporting detailed trial results; and monitoring the closeout process. Control Clin Trials 2001;22:29-41

Geriatric mental health education in Canada SKIPs into the 21st century

The Skills Immersion Program (SKIP) provides an educational opportunity for staff nurses who face the challenge of caring for residents who present with psychiatric and behavioral problems in long-term care (LTC) facilities within British Columbia, Canada. With the aging population and an increase in the number of individuals waiting for placement in care facilities, care providers are in substantial need of advanced education and training in the field of geriatric psychiatry nursing. Nurses working in LTC facilities in Canada are not prepared to manage the changing acuity levels and complex needs of their residents. The SKIP was developed by nurses, primarily for nurses, at St. Vincent's Hospital in Vancouver, British Columbia, Canada. Nurses who participate in the SKIP acquire an enhanced knowledge base in geriatric psychiatry nursing and gain access to assessment tools that will assist staff to increase the quality of care for their residents.

Fat contents of cereal foods: comparison of classical with recently developed extraction techniques

Eight cereal products ranging from a fat-free ready-to-eat (RTE) cereal (frosted flakes) to a full-fat high-ratio cake mix were subjected to analyte separation by anhydrous diethyl ether extraction (EE), acid hydrolysis/mixed ether extraction (AH), solid-phase extraction (SPE), and supercritical fluid extraction (SFE) with CO2 and with CO2 modified with 15% ethanol (SFEmod). Gravimetric analyses of extracts indicated higher (P < or = 0.05) crude fat values by AH than by EE, SFE, or SFEmod. Extractions followed by fatty acid methyl ester analysis also produced higher (P < or = 0.05) triglyceride means by AH than by other methods used for heat-treated RTE cereals and for ready-to-cook (RTC) cream of wheat. Therefore, for labeling purposes, AH seems most appropriate because in most cases it achieves higher triglyceride values than extraction with solvent(s) alone. SFE and SPE, on the other hand, yield fat values similar to those obtained by EE and offer the advantages of reduced solvent volume, short extraction times, and ease of laboratory automation.