Associations between Plasma Tocopherols and Lung Cancer Risk: Results from the Southern Community Cohort Study

BACKGROUND

Despite the various anticancer activities of tocopherols, little is known about tocopherols associated with lung cancer risk among low-income African Americans (AA) and European Americans (EA) who are disproportionately affected by the disease.

METHODS

We conducted a nested case-control study that included 209 incident lung cancer cases and 406 matched controls within the Southern Community Cohort Study. Using biospecimens collected at cohort enrollment, plasma levels of α-, β/γ-, δ-, and total-tocopherols were measured by high-performance liquid chromatography with photodiode array detection. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI) for lung cancer risk after adjusting for potential confounders. Stratified analyses were also conducted.

RESULTS

Plasma levels of total-tocopherols were inversely associated with lung cancer risk overall [OR (95% CI) for the highest vs. lowest tertile = 0.51 (0.30-0.90)]. The inverse association remained significant among EAs [0.20 (0.06-0.65)], men [0.43 (0.21-0.90)], current smokers [0.49 (0.26-0.93)], and cases diagnosed within 2 years of blood draw [0.36 (0.15-0.86)], though we did not find a significant risk reduction among AAs [0.75 (0.39-1.45)]. Notably, we found significant interactions between α-tocopherol and race after controlling the FDR to correct for multiple comparisons (Pinteraction = 0.02).

CONCLUSIONS

Our results indicate that plasma total-tocopherols are inversely associated with lung cancer risk, but the association may differ across specific isomeric forms of tocopherols, race, or other individuals' characteristics. Further large-scale studies are warranted to confirm our findings.

IMPACT

Recommendations on tocopherols for lung cancer prevention should take isomers, race, and smoking behaviors into consideration.

Diabetes and pancreatic cancer risk in a multiracial cohort

AIMS

To determine the relationship of diabetes with pancreatic cancer incidence among African American and Whites of similar socio-economic status.

METHODS

Using the Southern Community Cohort Study, we conducted a follow-up during 2002-2015 of pancreatic cancer incidence of 73,378 mostly low-income participants aged 40-79 years; 15,913 reported diabetes at baseline. Multivariable Cox analysis controlling for sex, family history of pancreatic cancer, BMI, smoking status, alcohol consumption, education, income and other important covariates, and with age as the timescale was used.

RESULTS

Totally, 265 incident pancreatic cancer cases were observed. Pancreatic cancer risk was increased among those with diabetes (HR 1.54, CI 1.16-2.05), with similar increases among African Americans (HR 1.51, CI 1.08-2.11) and Whites (HR 1.78, CI 1.00-3.16). No trend in risk was observed for diabetes duration among those with diabetes, with HRs of 1.39 (0.91-2.11), 2.31 (1.51-3.54) and 1.23 (0.80-1.89) for <5, 5-9 and 10+ years duration, respectively. African Americans were at increased risk of pancreatic cancer (HR = 1.40, 95% CI 1.05-1.87), which persisted after adjusting for diabetes (HR 1.36, CI 1.02-1.81). The effect sizes for other pancreatic cancer risk factors with pancreatic cancer were similar by diabetes status, although a stronger association with low BMI was evident among those with diabetes.

CONCLUSIONS

Diabetes increases pancreatic cancer risk similarly among African Americans and Whites in this Southern U.S.

COHORT

Feasibility of precision smoking treatment in a low-income community setting: results of a pilot randomized controlled trial in The Southern Community Cohort Study

BACKGROUND

The feasibility of precision smoking treatment in socioeconomically disadvantaged communities has not been studied.

METHODS

Participants in the Southern Community Cohort Study who smoked daily were invited to join a pilot randomized controlled trial of three smoking cessation interventions: guideline-based care (GBC), GBC plus nicotine metabolism-informed care (MIC), and GBC plus counseling guided by a polygenic risk score (PRS) for lung cancer. Feasibility was assessed by rates of study enrollment, engagement, and retention, targeting > 70% for each. Using logistic regression, we also assessed whether feasibility varied by age, sex, race, income, education, and attitudes toward precision smoking treatment.

RESULTS

Of 92 eligible individuals (79.3% Black; 68.2% with household income < $15,000), 67 (72.8%; 95% CI 63.0-80.9%) enrolled and were randomized. Of these, 58 (86.6%; 95% CI 76.4-92.8%) engaged with the intervention, and of these engaged participants, 43 (74.1%; 95% CI 61.6-83.7%) were retained at 6-month follow-up. Conditional on enrollment, older age was associated with lower engagement (OR 0.83, 95% CI 0.73-0.95, p = 0.008). Conditional on engagement, retention was significantly lower in the PRS arm than in the GBC arm (OR 0.18, 95% CI 0.03-1.00, p = 0.050). No other selection effects were observed.

CONCLUSIONS

Genetically informed precision smoking cessation interventions are feasible in socioeconomically disadvantaged communities, exhibiting high enrollment, engagement, and retention irrespective of race, sex, income, education, or attitudes toward precision smoking treatment. Future smoking cessation interventions in this population should take steps to engage older people and to sustain participation in interventions that include genetic risk counseling.

TRIAL REGISTRATION

ClinicalTrials.gov No. NCT03521141, Registered 27 April 2018, https://www.

CLINICALTRIALS

gov/study/NCT03521141.

Epigenome-wide association study of total nicotine equivalents in multiethnic current smokers from three prospective cohorts

The impact of tobacco exposure on health varies by race and ethnicity and is closely tied to internal nicotine dose, a marker of carcinogen uptake. DNA methylation is strongly responsive to smoking status and may mediate health effects, but study of associations with internal dose is limited. We performed a blood leukocyte epigenome-wide association study (EWAS) of urinary total nicotine equivalents (TNEs; a measure of nicotine uptake) and DNA methylation measured using the MethylationEPIC v1.0 BeadChip (EPIC) in six racial and ethnic groups across three cohort studies. In the Multiethnic Cohort Study (discovery, n = 1994), TNEs were associated with differential methylation at 408 CpG sites across >250 genomic regions (p < 9 × 10-8). The top significant sites were annotated to AHRR, F2RL3, RARA, GPR15, PRSS23, and 2q37.1, all of which had decreasing methylation with increasing TNEs. We identified 45 novel CpG sites, of which 42 were unique to the EPIC array and eight annotated to genes not previously linked with smoking-related DNA methylation. The most significant signal in a novel gene was cg03748458 in MIR383;SGCZ. Fifty-one of the 408 discovery sites were validated in the Singapore Chinese Health Study (n = 340) and the Southern Community Cohort Study (n = 394) (Bonferroni corrected p < 1.23 × 10-4). Significant heterogeneity by race and ethnicity was detected for CpG sites in MYO1G and CYTH1. Furthermore, TNEs significantly mediated the association between cigarettes per day and DNA methylation at 15 sites (average 22.5%-44.3% proportion mediated). Our multiethnic study highlights the transethnic and ethnic-specific methylation associations with internal nicotine dose, a strong predictor of smoking-related morbidities.

Sodium Intake and Cause-Specific Mortality Among Predominantly Low-Income Black and White US Residents

IMPORTANCE

Epidemiologic evidence regarding the outcomes of dietary sodium intake on mortality remains limited for low-income individuals, particularly Black people.

OBJECTIVE

To investigate the associations of excessive dietary sodium with all-cause and cause-specific mortality among predominantly low-income Black and White Americans.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included participants aged 40 to 79 years from the Southern Community Cohort Study who were recruited at Community Health Centers in 12 southeastern states from 2002 to 2009. Analyses were conducted between March 2022 and June 2023.

EXPOSURES

Dietary sodium intake was assessed using a validated food frequency questionnaire at baseline.

MAIN OUTCOMES AND MEASURES

Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for mortality outcomes (all-cause, cardiovascular disease [CVD], coronary heart disease [CHD], stroke, heart failure, cancer, and other) associated with sodium intake. Nonlinear associations and population-attributable risk (PAR) of the mortality burden associated with excess sodium were further assessed.

RESULTS

Among the 64 329 participants, 46 185 (71.8%) were Black, 18 144 (28.2%) were White, and 39 155 (60.9%) were female. The mean (SD) age at study enrollment was 51.3 (8.6) years for Black participants and 53.3 (9.3) years for White counterparts. Mean (SD) dietary sodium intake was 4512 (2632) mg/d in Black individuals and 4041 (2227) mg/d in White individuals; 37 482 Black individuals (81.2%) and 14 431 White individuals (79.5%) exceeded the current dietary recommendations of 2300 mg/d. During a median (IQR) follow-up of 13.8 (11.3-15.8) years, 17 811 deaths were documented, including 5701 from CVD. After adjustment for potential confounders, in Black individuals, HRs per 1000-mg increase in daily sodium intake were 1.07 (95% CI, 1.03-1.10) and 1.08 (95% CI, 1.02-1.14) for deaths from total CVD and CHD, respectively; while in White individuals, the corresponding HRs were 1.08 (95% CI, 1.02-1.14) and 1.13 (95% CI, 1.03-1.23). No significant associations were found for cancer mortality. PAR estimates suggest that sodium intake above the recommended threshold may account for 10% of total CVD, 13% of CHD, and 30% of heart failure deaths in this low-income southern population.

CONCLUSIONS AND RELEVANCE

In this cohort study of 64 329 low-income Americans, nearly 80% of study participants consumed sodium exceeding the current recommended daily amount, which was associated with 10% to 30% of CVD mortality. Public health programs targeted to reduce sodium intake among this underserved population may be beneficial.

Impacts of Poverty and Lifestyles on Mortality: A Cohort Study in Predominantly Low-Income Americans

INTRODUCTION

Low socioeconomic status has been linked to increased mortality. However, the impacts of poverty, alone or combined with health behaviors, on mortality and life expectancy have not been adequately investigated.

METHODS

Data from the Southern Community Cohort Study was used, including nearly 86,000 participants recruited during 2002-2009 across 12 US southeastern states. Analysis was conducted from February 2022 to January 2023.

RESULTS

During a median follow-up of 12.1 years, 19,749 deaths were identified. A strong dose-response relationship was found between household incomes and mortality, with a 3.3-fold (95%CI=3.1-3.6) increased all-cause mortality observed for individuals in the lowest income group (<$15,000/year) compared with those in the highest group (≥$50,000/year). Within each income group, mortality monotonically increased with declining healthy lifestyle score. Risk was significantly lower among those in the lowest income but healthiest lifestyle group, compared to those with the highest income but unhealthiest lifestyle (HR=0.82, 95%CI=0.69-0.97). Poor White participants appeared to experience higher all-cause mortality than poor Black participants. Life expectancy was more than 10.0 years shorter for those in the lowest income group compared with those in the highest income group.

CONCLUSIONS

Poverty is strongly associated with increased risk of death, but the risks could be modestly abated by a healthier lifestyle. These findings call for a comprehensive strategy for enhancing a healthy lifestyle and improving income equality to reduce death risks, particularly among those experiencing health disparities due to poverty.

Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

Diet quality and lung cancer incidence in a low-income population in the United States

BACKGROUND

Although tobacco smoking is the leading cause of lung cancer, interest in the relationship of diet quality on risk has been growing.

METHODS

We examined the association between Healthy Eating Index-2010 (HEI-10) at enrollment and lung cancer incidence among 70,802 participants in a predominantly African American and low-income prospective cohort in the southern United States. Outcomes were ascertained through linkages with state cancer registries and the National Death Index (NDI). Hazard ratios by HEI-10 quartiles were assessed using Cox proportional hazard models adjusted for potential confounders.

RESULTS

During ≤16 years of follow-up, 1454 incident lung cancers were identified. The lowest HEI-10 quartile compared to the highest was adversely associated with lung cancer risk (HR: 1.89, 95% CI 1.16-3.07) among male former smokers and female never smokers (HR: 2.58, 95% CI 1.06-6.28).

CONCLUSIONS

Low-quality diet was associated with increased lung cancer risk among male former smokers and female never smokers but cautious interpretation of the findings should be taken due to the small number of lung cancers among never smokers and the possibility of residual confounding by smoking in ever smokers.

Evaluating approaches for constructing polygenic risk scores for prostate cancer in men of African and European ancestry

Genome-wide polygenic risk scores (GW-PRSs) have been reported to have better predictive ability than PRSs based on genome-wide significance thresholds across numerous traits. We compared the predictive ability of several GW-PRS approaches to a recently developed PRS of 269 established prostate cancer-risk variants from multi-ancestry GWASs and fine-mapping studies (PRS269). GW-PRS models were trained with a large and diverse prostate cancer GWAS of 107,247 cases and 127,006 controls that we previously used to develop the multi-ancestry PRS269. Resulting models were independently tested in 1,586 cases and 1,047 controls of African ancestry from the California Uganda Study and 8,046 cases and 191,825 controls of European ancestry from the UK Biobank and further validated in 13,643 cases and 210,214 controls of European ancestry and 6,353 cases and 53,362 controls of African ancestry from the Million Veteran Program. In the testing data, the best performing GW-PRS approach had AUCs of 0.656 (95% CI = 0.635-0.677) in African and 0.844 (95% CI = 0.840-0.848) in European ancestry men and corresponding prostate cancer ORs of 1.83 (95% CI = 1.67-2.00) and 2.19 (95% CI = 2.14-2.25), respectively, for each SD unit increase in the GW-PRS. Compared to the GW-PRS, in African and European ancestry men, the PRS269 had larger or similar AUCs (AUC = 0.679, 95% CI = 0.659-0.700 and AUC = 0.845, 95% CI = 0.841-0.849, respectively) and comparable prostate cancer ORs (OR = 2.05, 95% CI = 1.87-2.26 and OR = 2.21, 95% CI = 2.16-2.26, respectively). Findings were similar in the validation studies. This investigation suggests that current GW-PRS approaches may not improve the ability to predict prostate cancer risk compared to the PRS269 developed from multi-ancestry GWASs and fine-mapping.

Calcium Intake and Lung Cancer Risk: A Pooled Analysis of 12 Prospective Cohort Studies

BACKGROUND

Previous studies on calcium intake and lung cancer risk reported inconsistent associations, possibly due to the differences in intake amounts and contributing sources of calcium and smoking prevalence.

OBJECTIVES

We investigated the associations of lung cancer risk with intake of calcium from foods and/or supplements and major calcium-rich foods in 12 studies.

METHODS

Data from 12 prospective cohort studies conducted in the United States, Europe, and Asia were pooled and harmonized. We applied the DRI to categorize calcium intake based on the recommendations and quintile distribution to categorize calcium-rich food intake. We ran multivariable Cox regression by each cohort and pooled risk estimates to compute overall HR (95% CI).

RESULTS

Among 1,624,244 adult men and women, 21,513 incident lung cancer cases were ascertained during a mean follow-up of 9.9 y. Overall, the dietary calcium intake was not significantly associated with lung cancer risk; the HRs (95% CI) were 1.08 (0.98-1.18) for higher (>1.5 RDA) and 1.01 (0.95-1.07) for lower intake (<0.5 RDA) comparing with recommended intake (EAR to RDA). Milk and soy food intake were positively or inversely associated with lung cancer risk [HR (95% CI) = 1.07 (1.02-1.12) and 0.92 (0.84-1.00)], respectively. The positive association with milk intake was significant only in European and North American studies (P-interaction for region = 0.04). No significant association was observed for calcium supplements.

CONCLUSIONS

In this largest prospective investigation, overall, calcium intake was not associated with risk of lung cancer, but milk intake was associated with a higher risk. Our findings underscore the importance of considering food sources of calcium in studies of calcium intake.

Evidence of Novel Susceptibility Variants for Prostate Cancer and a Multiancestry Polygenic Risk Score Associated with Aggressive Disease in Men of African Ancestry

BACKGROUND

Genetic factors play an important role in prostate cancer (PCa) susceptibility.

OBJECTIVE

To discover common genetic variants contributing to the risk of PCa in men of African ancestry.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a meta-analysis of ten genome-wide association studies consisting of 19378 cases and 61620 controls of African ancestry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Common genotyped and imputed variants were tested for their association with PCa risk. Novel susceptibility loci were identified and incorporated into a multiancestry polygenic risk score (PRS). The PRS was evaluated for associations with PCa risk and disease aggressiveness.

RESULTS AND LIMITATIONS

Nine novel susceptibility loci for PCa were identified, of which seven were only found or substantially more common in men of African ancestry, including an African-specific stop-gain variant in the prostate-specific gene anoctamin 7 (ANO7). A multiancestry PRS of 278 risk variants conferred strong associations with PCa risk in African ancestry studies (odds ratios [ORs] >3 and >5 for men in the top PRS decile and percentile, respectively). More importantly, compared with men in the 40-60% PRS category, men in the top PRS decile had a significantly higher risk of aggressive PCa (OR = 1.23, 95% confidence interval = 1.10-1.38, p = 4.4 × 10-4).

CONCLUSIONS

This study demonstrates the importance of large-scale genetic studies in men of African ancestry for a better understanding of PCa susceptibility in this high-risk population and suggests a potential clinical utility of PRS in differentiating between the risks of developing aggressive and nonaggressive disease in men of African ancestry.

PATIENT SUMMARY

In this large genetic study in men of African ancestry, we discovered nine novel prostate cancer (PCa) risk variants. We also showed that a multiancestry polygenic risk score was effective in stratifying PCa risk, and was able to differentiate risk of aggressive and nonaggressive disease.

Evaluating Approaches for Constructing Polygenic Risk Scores for Prostate Cancer in Men of African and European Ancestry

Genome-wide polygenic risk scores (GW-PRS) have been reported to have better predictive ability than PRS based on genome-wide significance thresholds across numerous traits. We compared the predictive ability of several GW-PRS approaches to a recently developed PRS of 269 established prostate cancer risk variants from multi-ancestry GWAS and fine-mapping studies (PRS 269 ). GW-PRS models were trained using a large and diverse prostate cancer GWAS of 107,247 cases and 127,006 controls used to develop the multi-ancestry PRS 269 . Resulting models were independently tested in 1,586 cases and 1,047 controls of African ancestry from the California/Uganda Study and 8,046 cases and 191,825 controls of European ancestry from the UK Biobank and further validated in 13,643 cases and 210,214 controls of European ancestry and 6,353 cases and 53,362 controls of African ancestry from the Million Veteran Program. In the testing data, the best performing GW-PRS approach had AUCs of 0.656 (95% CI=0.635-0.677) in African and 0.844 (95% CI=0.840-0.848) in European ancestry men and corresponding prostate cancer OR of 1.83 (95% CI=1.67-2.00) and 2.19 (95% CI=2.14-2.25), respectively, for each SD unit increase in the GW-PRS. However, compared to the GW-PRS, in African and European ancestry men, the PRS 269 had larger or similar AUCs (AUC=0.679, 95% CI=0.659-0.700 and AUC=0.845, 95% CI=0.841-0.849, respectively) and comparable prostate cancer OR (OR=2.05, 95% CI=1.87-2.26 and OR=2.21, 95% CI=2.16-2.26, respectively). Findings were similar in the validation data. This investigation suggests that current GW-PRS approaches may not improve the ability to predict prostate cancer risk compared to the multi-ancestry PRS 269 constructed with fine-mapping.

Abstract 4201: Associations of pre-diagnostic serum liver enzymes levels with lung cancer risk: results from the Southern Community Cohort Study

Introduction: Lung cancer is the leading cause of cancer death in the United States (U.S.). Lung cancer disproportionately affects African Americans (AAs) more than other racial/ethnic groups. Previous studies have linked liver diseases to lung cancer risk; however, few studies have evaluated the associations of circulating liver enzyme levels with lung cancer risk. In this study, we evaluated the associations of the serum alanine transaminase (ALT) and alkaline phosphatase (ALP) levels with the risk of subsequently developing lung cancer.

Methods: We conducted a nested case-control study within the Southern Community Cohort Study, a well-conducted prospective cohort study in the southern U.S. mainly consisting of low-income AAs and European Americans (EAs). We included 552 incident lung cancer cases and 1,039 controls individually matched on age, sex, recruitment sites, and date of blood draw. Baseline serum levels of ALT and ALP were measured using the Beckman Coulter clinical chemistry analyzer. Conditional logistic regression and generalized estimating models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for age, education, household income, body mass index (BMI), smoking status, pack-years, alcohol consumption, physical activity levels, history of chronic obstructive pulmonary disease, hypertension, and diabetes.

Results: Higher serum levels of ALT were associated with a lower overall risk of lung cancer. Compared with the lowest tertile, participants in the second and third tertiles had OR (95% CI) of 0.74 (0.48-1.14) and 0.47 (0.28-0.78) (Ptrend &lt; 0.01). The inverse association was observed in both AAs and EAs. However, the inverse associations between serum ALT levels and lung cancer risk were more evident among men [ORT3 vs T1 = 0.36 (0.18-0.70)], current smokers [ORT3 vs T1 =0.65 (0.47-0.90)], participants with lower BMI [ORT3 vs T1=0.55 (0.38-0.79)], or lower physical activity [ORT3 vs T1 = 0.55 (0.37-0.83)]. Stratified analyses by time interval between blood collection and lung cancer diagnosis showed that the inverse associations were observed in both those diagnosed within [ORT3 vs T1 =0.48 (0.23-1.00)] and after [ORT3 vs T1 = 0.36 (0.19-0.69)] a median follow up time of 3 years. The serum ALT level was not associated with overall lung cancer; however, higher serum ALP levels were significantly associated with increased lung cancer risk among AA men [ORT3 vs T1 = 1.98 (1.18-3.34)].

Conclusion: Our results indicate that in a predominantly low-income AA and EA population, serum ALT levels may be related to a lower risk of lung cancer. Further studies are warranted to confirm our findings and elucidate the potential underlying mechanisms of the associations.

Citation Format: Shuai Xu, Hui Cai, Jie Wu, Hyung-Suk Yoon, Regina Courtney, Xiao-Ou Shu, William J. Blot, Wei Zheng, Qiuyin Cai. Associations of pre-diagnostic serum liver enzymes levels with lung cancer risk: results from the Southern Community Cohort Study. [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 4201.

Physical activity in association with mortality among Black women diagnosed with breast cancer in the Southern Community Cohort Study

PURPOSE

Physical activity (PA) is associated with many health benefits. While PA has been associated with reduced mortality after breast cancer diagnosis in many studies, few studies have examined the role of PA in breast cancer survival among underserved and minority populations, including Black women. We investigated PA in association with mortality among Black predominantly low-income breast cancer survivors in the Southern Community Cohort Study (SCCS).

METHODS

Study participants were women diagnosed with incident breast cancer (n = 949) in the SCCS, which is a prospective cohort study of predominantly low-income adults aged 40-79 years recruited from 12 Southeastern states between 2002 and 2009. Participants completed a detailed baseline questionnaire, with annual follow-up for mortality via registry linkages. Cox regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of pre-diagnosis PA (measured via a validated questionnaire) with all-cause and breast cancer-specific mortality.

RESULTS

Breast cancer survivors had a mean age of 61.1 years and most (79.3%) had a household income of < $25,000. In adjusted models, higher levels of total PA (MET-hours/day) were inversely associated with all-cause mortality with HRs (95% CIs): 0.79 (0.59-1.06), 0.66 (0.49-0.90), and 0.60 (0.43-0.84), for Q2, Q3, and Q4 (reference: Q1), respectively, ptrend ≤ 0.01. A similar inverse association was found for breast cancer-specific mortality.

CONCLUSION

Higher levels of pre-diagnosis PA were associated with improved survival among low-income Black breast cancer survivors. Resources to reduce barriers to PA participation and increase support for education and intervention efforts to promote PA among Black women are needed.

Genome-wide association study (GWAS) of circulating vitamin D outcomes among individuals of African ancestry

BACKGROUND

Vitamin D deficiency is more common among African-ancestry individuals and may be associated with adverse health outcomes. Vitamin D binding protein (VDBP) regulates concentrations of biologically active vitamin D.

OBJECTIVE

We conducted genome-wide association study (GWAS) of VDBP and 25-hydroxyvitamin D among African-ancestry individuals.

METHODS

Data were collected from 2,602 African American adults from the Southern Community Cohort Study (SCCS) and 6,934 African- or Caribbean-ancestry adults from the UK Biobank. Serum VDBP concentrations were available only in the SCCS and were measured by using the Polyclonal Human VDBP ELISA kit. Serum 25-hydroxyvitamin D concentrations for both study samples were measured by using Diasorin Liason, a chemiluminescent immunoassay. Participants were genotyped for single nucleotide polymorphisms (SNPs) with genome-wide coverage by using Illumina or Affymetrix platforms. Fine-mapping analysis was performed by using forward stepwise linear regression models including all variants with P value < 5 × 10-8 and within 250 kbps of a lead SNP.

RESULTS

We identified 4 loci notably associated with VDBP concentrations in the SCCS population: rs7041 (per allele β = 0.61 μg/mL, SE = 0.05, P = 1.4 × 10-48) and rs842998 (per allele β = 0.39 μg/mL, SE = 0.03, P = 4.0 × 10-31) in GC, rs8427873 (per allele β = 0.31 μg/mL, SE = 0.04, P = 3.0 × 10-14) near GC and rs11731496 (per allele β = 0.21 μg/mL, SE = 0.03, P = 3.6 × 10-11) in between GC and NPFFR2. In conditional analyses, which included the above-mentioned SNPs, only rs7041 remained notable (P = 4.1 × 10-21). SNP rs4588 in GC was the only GWAS-identified SNP associated with 25-hydroxyvitamin D concentration. Among UK Biobank participants: per allele β = -0.11 μg/mL, SE = 0.01, P = 1.5 × 10-13; in the SCCS: per allele β = -0.12 μg/mL, SE = 0.06, P = 2.8 × 10-02). rs7041 and rs4588 are functional SNPs that influence the binding affinity of VDBP to 25-hydroxyvitamin D.

CONCLUSIONS

Our results were in line with previous studies conducted in European-ancestry populations, showing that GC, the gene that directly encodes for VDBP, would be important for VDBP and 25-hydroxyvitamin D concentrations. The current study extends our knowledge of the genetics of vitamin D in diverse populations.

Associations between serum vitamin D biomarkers and tumor expression of Ki67, p53, and COX-2 in colorectal cancer cases from the Southern Community Cohort Study

Higher 25-hydroxyvitamin D is associated with lower colorectal cancer (CRC) risk, with limited data from African Americans (AAs), who have greater risk for CRC and 25-hydroxyvitamin D deficiency. In a predominantly AA sample of CRC cases from the Southern Community Cohort Study (SCCS), we report associations between vitamin D biomarkers and tumor expression of proteins implicated in vitamin D's anti-tumorigenic pathways (e.g. proliferation and inflammation) and CRC prognosis. SCCS participants with incident CRC were identified via state cancer registries. Serum 25-hydroxyvitamin D and vitamin D binding protein (VDBP) were measured at enrollment. 'Free' 25-hydroxyvitamin D was calculated via standard equation. Cellular Ki67, p53, and COX-2 were measured from tumor samples and categorized using literature-defined cut-points related to survival. Generalized linear models were used to measure associations between vitamin D exposures, tumor biomarkers, and stage. In total, 104 cases (40-79 years) were analyzed. 25-hydroxyvitamin D was not associated with high Ki67 (odds ratio (OR) per 1-standard deviation (SD) increase [95% confidence interval] 1.35[0.86-2.11]), p53 (0.75[0.47-1.20]), or COX-2 expression (1.25[0.78-2.01]), or metastatic disease (1.04[0.59-1.81]). Mean biomarker expression was unrelated to 25-hydroxyvitamin D (p-trend ≥.09). Null associations were observed for VDBP and free 25-hydroxyvitamin D. In AAs (n = 70), higher VDBP was associated with lower odds of high Ki67 expression (0.53[0.28-0.98], p-trend =.04). In conclusion, we observed no associations between 25-hydroxyvitamin D and prognostic marker expression in CRC. An inverse association between VDBP and tumor Ki67 in AAs is consistent with reports showing relationships with reduced CRC mortality.

Association of Race and Income with Incident Diagnosis of Alzheimer's Disease and Related Dementias among Black and White Older Adults

To investigate how differences in income and education levels may contribute to disparities in incidence of Alzheimer's disease and related dementia (ADRD), we compared ADRD incidence in traditional Medicare claims for 11,132 Black and 7703 White participants aged 65 and over from a predominantly low-income cohort. We examined whether the relationship between ADRD incidence and race varied by income or education. Based on 2015 incident ADRD diagnoses, Black and White participants had unadjusted incidence rates of 26.5 and 23.2 cases per 1000 person-years, respectively (rate ratio 1.14, 95% CI 1.05-1.25). In multivariable Cox proportional hazard models, the relationship between race and incident ADRD diagnosis did not vary by education level (p-interaction = 0.748) but was modified by income level (p-interaction = 0.007), with higher ADRD incidence among Black participants observed only among higher income groups. These results highlight the importance of understanding how race and economic factors influence ADRD incidence and diagnosis rates.

Pre-diagnostic circulating p53 autoantibodies and subsequent lung cancer risk in low-income African and European Americans

INTRODUCTION

Mutations of the TP53 gene lead to the production of autoantibodies against p53, a major tumor suppressor protein. Although studies have indicated the association of p53 autoantibodies with human cancers, epidemiologic evidence on lung cancer is still lacking.

METHODS

In this nested case-control study conducted within the Southern Community Cohort Study, we investigated the association of circulating p53 autoantibodies with the subsequent risk of developing lung cancer. Using blood samples collected prior to any cancer diagnosis from 295 cases and their individually matched controls, seroreactivity to p53 was assessed by fluorescent bead-based multiplex serology. Conditional logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for lung cancer risk associated with p53 autoantibodies.

RESULTS

After adjustment for potential confounders, p53 seropositivity was significantly associated with an increased risk of lung cancer (OR=2.98, 95 % CI: 1.10-8.06) among African Americans, but not among European Americans (OR=1.21, 95 % CI: 0.24-6.15). The positive associations were restricted to men (OR=4.59, 95 % CI: 1.30-16.16) and participants with a short interval (≤ 4 years) from blood collection to diagnosis (OR=4.30, 95 % CI: 1.33-13.89).

CONCLUSION

Our findings add to the evidence supporting p53 autoantibodies as a biomarker of lung cancer.

Absolute Risk of Oropharyngeal Cancer After an HPV16-E6 Serology Test and Potential Implications for Screening: Results From the Human Papillomavirus Cancer Cohort Consortium

PURPOSE

Seropositivity for the HPV16-E6 oncoprotein is a promising marker for early detection of oropharyngeal cancer (OPC), but the absolute risk of OPC after a positive or negative test is unknown.

METHODS

We constructed an OPC risk prediction model that integrates (1) relative odds of OPC for HPV16-E6 serostatus and cigarette smoking from the human papillomavirus (HPV) Cancer Cohort Consortium (HPVC3), (2) US population risk factor data from the National Health Interview Survey, and (3) US sex-specific population rates of OPC and mortality.

RESULTS

The nine HPVC3 cohorts included 365 participants with OPC with up to 10 years between blood draw and diagnosis and 5,794 controls. The estimated 10-year OPC risk for HPV16-E6 seropositive males at age 50 years was 17.4% (95% CI, 12.4 to 28.6) and at age 60 years was 27.1% (95% CI, 19.2 to 45.4). Corresponding 5-year risk estimates were 7.3% and 14.4%, respectively. For HPV16-E6 seropositive females, 10-year risk estimates were 3.6% (95% CI, 2.5 to 5.9) at age 50 years and 5.5% (95% CI, 3.8 to 9.2) at age 60 years and 5-year risk estimates were 1.5% and 2.7%, respectively. Over 30 years, after a seropositive result at age 50 years, an estimated 49.9% of males and 13.3% of females would develop OPC. By contrast, 10-year risks among HPV16-E6 seronegative people were very low, ranging from 0.01% to 0.25% depending on age, sex, and smoking status.

CONCLUSION

We estimate that a substantial proportion of HPV16-E6 seropositive individuals will develop OPC, with 10-year risks of 17%-27% for males and 4%-6% for females age 50-60 years in the United States. This high level of risk may warrant periodic, minimally invasive surveillance after a positive HPV16-E6 serology test, particularly for males in high-incidence regions. However, an appropriate clinical protocol for surveillance remains to be established.

Associations of Dietary Intakes of Carotenoids and Vitamin A with Lung Cancer Risk in a Low-Income Population in the Southeastern United States

Observational studies found inverse associations of dietary carotenoids and vitamin A intakes with lung cancer risk. However, interventional trials among high-risk individuals showed that β-carotene supplements increased lung cancer risk. Most of the previous studies were conducted among European descendants or Asians. We prospectively examined the associations of lung cancer risk with dietary intakes of carotenoids and vitamin A in the Southern Community Cohort Study, including 65,550 participants with 1204 incident lung cancer cases. Multivariate Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Lung cancer cases had lower energy-adjusted dietary intakes of all carotenoids and vitamin A than non-cases. However, dietary intakes of carotenoids and vitamin A were not associated with overall lung cancer risk. A significant positive association of dietary vitamin A intake with lung cancer risk was observed among current smokers (HR_{Q4 vs. Q1} = 1.23; 95% CI: 1.02-1.49; P_trend = 0.01). In addition, vitamin A intake was associated with an increased risk of adenocarcinoma among African Americans (HR_{Q4 vs. Q1} = 1.55; 95%CI: 1.08-2.21; P_trend = 0.03). Dietary lycopene intake was associated with an increased risk of lung cancer among former smokers (HR_{Q4 vs. Q1} = 1.50; 95% CI: 1.04-2.17; P_trend = 0.03). There are positive associations of dietary β-cryptoxanthin intake with squamous carcinoma risk (HR_{Q4 vs. Q1} = 1.49; 95% CI: 1.03-2.15; P_trend = 0.03). Further studies are warranted to confirm our findings.

Sociocultural Factors, Access to Healthcare, and Lifestyle: Multifactorial Indicators in Association with Colorectal Cancer Risk

Black Americans of low socioeconomic status (SES) have higher colorectal cancer incidence than other groups in the United States. However, much of the research that identifies colorectal cancer risk factors is conducted in cohorts of high SES and non-Hispanic White participants. Adult participants of the Southern Community Cohort Study (N = 75,182) were followed for a median of 12.25 years where 742 incident colorectal cancers were identified. The majority of the cohort are non-Hispanic White or Black and have low household income. Cox models were used to estimate HRs for colorectal cancer incidence associated with sociocultural factors, access to and use of healthcare, and healthy lifestyle scores to represent healthy eating, alcohol intake, smoking, and physical activity. The association between Black race and colorectal cancer was consistent and not diminished by accounting for SES, access to healthcare, or healthy lifestyle [HR = 1.34; 95% confidence interval (CI),1.10-1.63]. Colorectal cancer screening was a strong, risk reduction factor for colorectal cancer (HR = 0.65; 95% CI, 0.55-0.78), and among colorectal cancer-screened, Black race was not associated with risk. Participants with high school education were at lower colorectal cancer risk (HR = 0.81; 95% CI, 0.67-0.98). Income and neighborhood-level SES were not strongly associated with colorectal cancer risk. Whereas individual health behaviors were not associated with risk, participants that reported adhering to ≥3 health behaviors had a 19% (95% CI, 1-34) decreased colorectal cancer risk compared with participants that reported ≤1 behaviors. The association was consistent in fully-adjusted models, although HRs were no longer significant. Colorectal cancer screening, education, and a lifestyle that includes healthy behaviors lowers colorectal cancer risk. Racial disparities in colorectal cancer risk may be diminished by colorectal cancer screening.

PREVENTION RELEVANCE

Colorectal cancer risk may be reduced through screening, higher educational attainment and performing more health behaviors. Importantly, our data show that colorectal cancer screening is an important colorectal cancer prevention strategy to eliminate the racial disparity in colorectal cancer risk. See related Spotlight, p. 561.

Dispositional optimism and optimistic bias: Associations with cessation motivation, confidence, and attitudes

OBJECTIVE

To test whether 2 conceptually overlapping constructs, dispositional optimism (generalized positive expectations) and optimistic bias (inaccurately low risk perceptions), may have different implications for smoking treatment engagement.

METHOD

Predominantly Black, low-income Southern Community Cohort study smokers (n = 880) self-reported dispositional optimism and pessimism (Life Orientation Test-Revised subscales: 0 = neutral, 12 = high optimism/pessimism), comparative lung cancer risk (Low/Average/High), and information to calculate objective lung cancer risk (Low/Med/High). Perceived risk was categorized as accurate (perceived = objective), optimistically-biased (perceived < objective), or pessimistically-biased (perceived > objective). One-way ANOVAs tested associations between dispositional optimism/pessimism and perceived risk accuracy. Multivariable logistic regressions tested independent associations of optimism/pessimism and perceived risk accuracy with cessation motivation (Low/High), confidence (Low/High), and precision treatment attitudes (Favorable/Unfavorable), controlling for sociodemographics and nicotine dependence.

RESULTS

Mean dispositional optimism/pessimism scores were 8.41 (SD = 2.59) and 5.65 (SD = 3.02), respectively. Perceived lung cancer risk was 38% accurate, 27% optimistically-biased, and 35% pessimistically-biased. Accuracy was unrelated to dispositional optimism (F(2, 641) = 1.23, p = .29), though optimistically-biased (vs. pessimistically-biased) smokers had higher dispositional pessimism (F(2, 628) = 3.17, p = .043). Dispositional optimism was associated with higher confidence (Adjusted odds ratio [AOR] = 1.71, 95% CI [1.42, 2.06], p < .001) and favorable precision treatment attitudes (AOR = 1.66, 95% CI [1.37, 2.01], p < .001). Optimistically-biased (vs. accurate) risk perception was associated with lower motivation (AOR = .64, 95% CI [.42, .98], p = .041) and less favorable precision treatment attitudes (AOR = .59, 95% CI [.38, .94], p = .029).

CONCLUSIONS

Dispositional optimism and lung cancer risk perception accuracy were unrelated. Dispositional optimism was associated with favorable engagement-related outcomes and optimistically-biased risk perception with unfavorable outcomes, reinforcing the distinctiveness of these constructs and their implications for smoking treatment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Association of Healthy Lifestyles With Risk of Alzheimer Disease and Related Dementias in Low-Income Black and White Americans

BACKGROUND AND OBJECTIVES

Although the importance of healthy lifestyles for preventing Alzheimer disease and related dementias (ADRD) has been recognized, epidemiologic evidence remains limited for non-White or low-income individuals who bear disproportionate burdens of ADRD. This population-based cohort study aims to investigate associations of lifestyle factors, individually and together, with the risk of ADRD among socioeconomically disadvantaged Americans.

METHODS

In the Southern Community Cohort Study, comprising two-thirds self-reported Black and primarily low-income Americans, we identified incident ADRD using claims data among participants enrolled in Medicare for at least 12 consecutive months after age 65 years. Five lifestyle factors-tobacco smoking, alcohol consumption, leisure-time physical activity (LTPA), sleep hours, and diet quality-were each scored 0 (unhealthy), 1 (intermediate), or 2 (healthy) based on the health guidelines. A composite lifestyle score was created by summing all scores. Cox regression was used to estimate hazard ratios (HRs, 95% CIs) for incident ADRD, treating death as a competing risk.

RESULTS

We identified 1,694 patients with newly diagnosed ADRD among 17,209 participants during a median follow-up of 4.0 years in claims data; the mean age at ADRD diagnosis was 74.0 years. Healthy lifestyles were individually associated with an 11%-25% reduced risk of ADRD: multivariable-adjusted HR (95% CI) was 0.87 (0.76-0.99) for never vs current smoking, 0.81 (0.72-0.92) for low-to-moderate vs no alcohol consumption, 0.89 (0.77-1.03) for ≥150 minutes of moderate or ≥75 minutes of vigorous LTPA each week vs none, 0.75 (0.64-0.87) for 7-9 hours vs >9 hours of sleep, and 0.85 (0.75-0.96) for the highest vs lowest tertiles of the Healthy Eating Index. The composite lifestyle score showed a dose-response association with up to 36% reduced risk of ADRD: multivariable-adjusted HRs (95% CIs) across quartiles were 1 (ref), 0.88 (0.77-0.99), 0.79 (0.70-0.90), and 0.64 (0.55-0.74); p trend <0.001. The beneficial associations were observed regardless of participants' sociodemographics (e.g., race, education, and income) and health conditions (e.g., history of cardiometabolic diseases and depression).

DISCUSSION

Our findings support significant benefits of healthy lifestyles for ADRD prevention among socioeconomically disadvantaged Americans, suggesting that promoting healthy lifestyles and reducing barriers to lifestyle changes are crucial to tackling the growing burden and disparities posed by ADRD.

Evaluating breast cancer predisposition genes in women of African ancestry

PURPOSE

Studies conducted primarily among European ancestry women reported 12 breast cancer predisposition genes. However, etiologic roles of these genes in breast cancer among African ancestry women have been less well-investigated.

METHODS

We conducted a case-control study in African American women, which included 1117 breast cancer cases and 2169 cancer-free controls, and a pooled analysis, which included 7096 cases and 8040 controls of African descent. Odds ratios of associations with breast cancer risk were estimated.

RESULTS

Using sequence data, we identified 61 pathogenic variants in 12 breast cancer predisposition genes, including 11 pathogenic variants not yet reported in previous studies. Pooled analysis showed statistically significant associations of breast cancer risk with pathogenic variants in BRCA1, BRCA2, PALB2, ATM, CHEK2, TP53, NF1, RAD51C, and RAD51D (all P < .05). The associations with BRCA1, PALB2, and RAD51D were stronger for estrogen receptor (ER)-negative than for ER-positive breast cancer (P heterogeneity < .05), whereas the association with CHEK2 was stronger for ER-positive than for ER-negative breast cancer.

CONCLUSION

Our study confirmed previously identified associations of breast cancer risk with BRCA1, BRCA2, PALB2, ATM, TP53, NF1, and CHEK2 and provided new evidence to extend the associations of breast cancer risk with RAD51C and RAD51D, which was identified previously in European ancestry populations, to African ancestry women.

Associations of lung cancer risk with biomarkers of Helicobacter pylori infection

Helicobacter pylori infection has been suggested to be associated with lung cancer risk. However, information is lacking on whether the association differs by H. pylori antigen. We conducted a nested case-control study within the Southern Community Cohort Study, including 295 incident lung cancer cases and 295 controls. Helicobacter pylori multiplex serology assay was performed to detect antibodies to 15 H. pylori proteins. Conditional logistic regression was used to estimate odds ratios (ORs) and confidence intervals (95% CIs) after adjustment for covariates. Overall H. pylori+ was associated with a non-statistically significant increased risk of lung cancer (OR: 1.29; 95% CI: 0.85-1.95). Significant associations, however, were observed for H. pylori+ VacA+ (OR: 1.64; 95% CI: 1.02-2.62) and H. pylori+ Catalase+ (OR: 1.75; 95% CI: 1.11-2.77). The positive association of H. pylori+ Catalase+ with lung cancer risk was predominantly seen among African Americans (OR: 2.09; 95% CI: 1.11-3.95) but not European Americans (OR: 1.20; 95% CI: 0.56-2.54). Among participants who smoked ≥ 30 pack-years, overall H. pylori+ (OR: 1.85; 95% CI: 1.02-3.35), H. pylori+ CagA+ (OR: 2.77; 95% CI: 1.35-5.70), H. pylori+ VacA+ (OR: 2.53; 95% CI: 1.25-5.13) and H. pylori+ HP1564+ (OR: 2.01; 95% CI: 1.07-3.77) were associated with increased risk of lung cancer. Our study provides novel evidence that associations of H. pylori infection with lung cancer risk differ by H. pylori biomarker, may be more evident among African Americans and may be modified by smoking habits. Furthermore, studies are warranted to confirm our findings.

Associations of Pre-Diagnostic Serum Levels of Total Bilirubin and Albumin With Lung Cancer Risk: Results From the Southern Community Cohort Study

Background

Previous studies conducted among European and Asian decedents reported inverse associations of serum total bilirubin and albumin with lung cancer risk. Yet, no study has been conducted among African Americans or low-income European Americans.

Methods

This study included 522 incident lung cancer cases and 979 matched controls nested in the Southern Community Cohort Study, a cohort of predominantly low-income African and European Americans. Serum levels of total bilirubin and albumin, collected up to 11 years prior to case diagnoses, were measured by a clinical chemistry analyzer. Conditional logistic regression models were applied to evaluate the associations of total bilirubin and albumin with lung cancer risk.

Results

Overall, serum levels of total bilirubin (OR_{T3 vs. T1} = 0.96, 95% CI: 0.66-1.39) were not significantly associated with lung cancer risk. However, higher levels of serum total bilirubin were significantly associated with decreased risk of lung cancer among participants who were diagnosed within two years following sample collection (OR_{T3 vs. T1} = 0.36, 95% CI: 0.15-0.87) and among former/never smokers (OR_{T3 vs. T1} = 0.54, 95% CI: 0.32-0.93). Serum levels of albumin were significantly associated with decreased risk of lung cancer overall (OR_{T3 vs. T1} = 0.70, 95% CI: 0.50-0.98) and among African Americans (OR_{T3 vs. T1} = 0.62, 95% CI: 0.41-0.96), but not among European Americans.

Conclusion

Our results indicate that in a low-income African American and European American population, serum levels of total bilirubin may be related to lung cancer progression and differ by smoking status. Meanwhile, the association of serum albumin levels with lung cancer risk may differ by race. Further studies are warranted to confirm these results.

Abstract 725: Biomarkers of circulating vitamin D status and expression of tumor molecular markers Ki67, p53, and COX2 among colorectal cancer cases in the Southern Community Cohort Study

Introduction: Epidemiologic studies and controlled trials provide evidence that higher 25-hydroxyvitaminD is associated with improved survival in colorectal cancer (CRC), although there are limited data in African Americans (AAs), who are at greater risk for CRC mortality and vitamin D deficiency. Herein, we report associations between vitamin D serum biomarkers collected at cohort entry up to 15 years prior to CRC onset and CRC tumor subtypes defined by high expression of tumor markers (Ki67, p53, and COX2) that represent cellular processes (proliferation, apoptosis, and inflammation) affected by vitamin D. Importantly, higher expression of these markers reflects greater risk for metastasis and CRC-specific mortality.

Methods: Data arise from the Southern Community Cohort Study, a cohort from the southeastern United States where the majority of participants are AA. Incident CRC cases with tumor sample were analyzed (n=104). Expression of cellular Ki67, p53, and COX2 (% positivity) were measured and categorized by literature-defined high vs. low cut-points (20%, 10%, and 20%, respectively). Logistic models adjusted for age, race, and sex were used to measure associations between vitamin D biomarkers: 25-hydroxyvitaminD, vitamin D binding protein (VDBP), and calculated free 25-hydroxyvitaminD (vitamin D not bound by VDBP) and the odds of a more aggressive tumor subtype, defined by higher cellular expression. Associations were assessed in the full sample and the subsample of AAs (n=70).

Results: There were 52 tumors with high Ki67 expression, 37 with high p53, and 50 with high COX2. Fifteen tumors had high expression of all three markers. Cases were 55.8±0.4 (mean±SE) years at enrollment (range 40-79). The median 25-hydroxyvitaminD was lower in cases with high p53 expressing tumors compared to low expression (13.5 vs. 18.0 ng/mL, respectively, p = .03). Median values for other biomarkers were similar by tumor subtype (p &gt .05). 25-hydroxyvitaminD was not associated with having a tumor with high Ki67 expression (odds ratio (OR) per 1 SD increase [95% CI] = 1.29 [0.85-1.95], p-trend = .23), high p53 expression (0.80 [0.52-1.23], p-trend = .30), or high COX2 expression (1.29 [0.83-2.00], p = .25). We observed null associations for VDBP, and free 25-hydroxyvitaminD with all tumor subtypes. Results were similar in AAs, although higher VDBP was associated with lower odds of high Ki67 tumors (0.45 [0.21-0.97], p-trend = .04 per 1 SD increase).

Conclusion: In this sample of predominantly AA CRC cases, we observed no association between vitamin D biomarkers in stored serum and subsequent more aggressive CRC molecular subtypes. More work is needed to characterize the relationship between vitamin D and expression of CRC tumor markers, which may help clarify the protective role of maintaining adequate vitamin D levels in association with CRC.

Citation Format: Thomas Lawler, Timothy Su, Qiuyin Cai, Mark Steinwandel, Wei Zheng, William J. Blot, Shaneda Warren Andersen. Biomarkers of circulating vitamin D status and expression of tumor molecular markers Ki67, p53, and COX2 among colorectal cancer cases in the Southern Community Cohort Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 725.

Abstract 2262: Associations of plasma carotenes with lung cancer risk in a low-income population in the southeastern united states

Lung cancer is the second most common cancer and the leading cause of death from cancer in the U.S. Carotenes, with the properties of antioxidation and immunoregulation, have been demonstrated to have anti-carcinogenic effects. Previous prospective studies showed inverse associations of circulating α-carotene and β-carotene with lung cancer risk among European descendants and Asians. The associations of α-carotene and β-carotene isomers with lung cancer risk have not been investigated, particularly among African Americans (AAs) and low-income populations. We conducted a case-control study including 225 incident lung cancer cases and 429 controls, individually matched on age, race, and sex, nested in the Southern Community Cohort Study, including ~86,000 participants, two-thirds of whom are AAs. Carotene plasma concentrations were determined by a validated assay using high-pressure liquid chromatography with photo-diode array detection. Plasma trans-β-carotene (ORT3 VS. T1=0.54; 95% CI: 0.32-0.90; Ptrend=0.03), cis-β-carotene (ORT3 VS. T1=0.55; 95% CI: 0.32-0.93; Ptrend=0.03), and total β-carotene (ORT3 VS. T1=0.50; 95% CI: 0.30-0.84; Ptrend=0.01) were inversely associated with lung cancer risk. The associations remained significant after excluding cases diagnosed within the first year of follow-up. The inverse associations of plasma cis-β-carotene and total β-carotene with lung cancer risk were only observed among AAs and males. Plasma trans-α-carotene, trans-β-carotene, cis-β-carotene, and total β-carotene were inversely associated with lung cancer risk among those with lower body mass index (&lt;median). In summary, plasma levels of β-carotenes were inversely associated with lung cancer risk in AA and low-income populations. Further studies with a larger sample size are warranted to confirm our findings.

Citation Format: Yan Sun, Jie Wu, Hyung-Suk Yoon, Wei Zheng, Hui Cai, Maciej S. Buchowski, Adrian A. Franke, William J. Blot, Xiao-ou Shu, Qiuyin Cai. Associations of plasma carotenes with lung cancer risk in a low-income population in the southeastern united states [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2262.

Smoking Quit Rates Among Menthol vs Non-Menthol Smokers: Implications Regarding a US Ban on the Sale of Menthol Cigarettes

BACKGROUND

A ban on the sale of menthol cigarettes in the United States is currently under consideration. A justification is that menthol cigarettes are harder to quit, particularly for African American smokers who use menthols much more frequently than White smokers, but epidemiologic data are limited.

METHODS

In a cohort of 16,425 mostly low income African American and White current cigarette smokers enrolled during 2002-2009, we computed smoking quit and re-uptake rates at three follow ups conducted means of 4.6, 7.7 and 11 years after entry. Generalized estimation equations were used to compute odds ratios (OR) and 95% confidence intervals (CI) for quitting and resuming smoking for menthol vs non-menthol smokers adjusted for race, age, education, income, and smoking pack years.

RESULTS

Crude annual quit rates among current smokers were 4.3% for menthol and 4.5% for non-menthol smokers, with adjusted ORs of quitting for menthol vs non-menthol smokers of 1.01 (95% CI = 0.91-1.11) overall, 0.99 (95% CI = 0.87-1.12) among African American and 1.02 (95% CI = 0.88-1.20) among White smokers. Crude annual smoking re-uptake rates were somewhat higher among menthol (8.4%) than non-menthol smokers (7.1%), with an adjusted OR of 1.19 (95% CI = 0.97-1.47), but net quit rates remained similar (OR = 1.01 [95% CI = 0.90-1.13] overall; OR = 1.00 [95% CI = 0.86-1.15] among African American participants; and OR = 1.04 [95% CI = 0.87-1.24] among White participants).

CONCLUSIONS

This large-scale prospective survey revealed similar quit rates among menthol and non-menthol smokers. Results contribute to policy discussions, especially if, as a meta analysis suggests, lung cancer risk is higher for non-menthol smokers and a ban leads menthol smokers to switch to non-menthol cigarettes.

Depressive Symptoms and Incident Heart Failure Risk in the Southern Community Cohort Study

OBJECTIVES

This study aims to examine whether greater frequency of depressive symptoms associates with increased risk of incident heart failure (HF).

BACKGROUND

Depressive symptoms associate with adverse prognosis in patients with prevalent HF. Their association with incident HF is less studied, particularly in low-income and minority individuals.

METHODS

We studied 23,937 Black or White Southern Community Cohort Study participants (median age: 53 years, 70% Black, 64% women) enrolled between 2002 and 2009, without prevalent HF, receiving Centers for Medicare and Medicaid Services coverage. Cox models adjusted for traditional HF risk factors, socioeconomic and behavioral factors, social support, and antidepressant medications were used to quantify the association between depressive symptoms assessed at enrollment via the Center for Epidemiologic Studies Depression Scale (CESD-10) and incident HF ascertained from Centers for Medicare and Medicaid Services International Classification of Diseases-9th Revision (ICD-9) (code: 428.x) and ICD-10 (codes: I50, I110) codes through December 31, 2016.

RESULTS

The median CESD-10 score was 9 (IQR: 5 to 13). Over a median 11-year follow-up, 6,081 (25%) participants developed HF. The strongest correlates of CESD-10 score were antidepressant medication use, age, and socioeconomic factors, rather than traditional HF risk factors. Greater frequency of depressive symptoms associated with increased incident HF risk (per 8-U higher CESD-10 HR: 1.04; 95% CI: 1.00 to 1.09; P = 0.038) without variation by race or sex. The association between depressive symptoms and incident HF varied by antidepressant use (interaction-P = 0.03) with increased risk among individuals not taking antidepressants.

CONCLUSIONS

In this high-risk, low-income, cohort of predominantly Black participants, greater frequency of depressive symptoms significantly associates with higher risk of incident HF.

Prostate cancer risk stratification improvement across multiple ancestries with new polygenic hazard score

BACKGROUND

Prostate cancer risk stratification using single-nucleotide polymorphisms (SNPs) demonstrates considerable promise in men of European, Asian, and African genetic ancestries, but there is still need for increased accuracy. We evaluated whether including additional SNPs in a prostate cancer polygenic hazard score (PHS) would improve associations with clinically significant prostate cancer in multi-ancestry datasets.

METHODS

In total, 299 SNPs previously associated with prostate cancer were evaluated for inclusion in a new PHS, using a LASSO-regularized Cox proportional hazards model in a training dataset of 72,181 men from the PRACTICAL Consortium. The PHS model was evaluated in four testing datasets: African ancestry, Asian ancestry, and two of European Ancestry-the Cohort of Swedish Men (COSM) and the ProtecT study. Hazard ratios (HRs) were estimated to compare men with high versus low PHS for association with clinically significant, with any, and with fatal prostate cancer. The impact of genetic risk stratification on the positive predictive value (PPV) of PSA testing for clinically significant prostate cancer was also measured.

RESULTS

The final model (PHS290) had 290 SNPs with non-zero coefficients. Comparing, for example, the highest and lowest quintiles of PHS290, the hazard ratios (HRs) for clinically significant prostate cancer were 13.73 [95% CI: 12.43-15.16] in ProtecT, 7.07 [6.58-7.60] in African ancestry, 10.31 [9.58-11.11] in Asian ancestry, and 11.18 [10.34-12.09] in COSM. Similar results were seen for association with any and fatal prostate cancer. Without PHS stratification, the PPV of PSA testing for clinically significant prostate cancer in ProtecT was 0.12 (0.11-0.14). For the top 20% and top 5% of PHS290, the PPV of PSA testing was 0.19 (0.15-0.22) and 0.26 (0.19-0.33), respectively.

CONCLUSIONS

We demonstrate better genetic risk stratification for clinically significant prostate cancer than prior versions of PHS in multi-ancestry datasets. This is promising for implementing precision-medicine approaches to prostate cancer screening decisions in diverse populations.

A Rare Germline HOXB13 Variant Contributes to Risk of Prostate Cancer in Men of African Ancestry

A rare African ancestry-specific germline deletion variant in HOXB13 (X285K, rs77179853) was recently reported in Martinican men with early-onset prostate cancer. Given the role of HOXB13 germline variation in prostate cancer, we investigated the association between HOXB13 X285K and prostate cancer risk in a large sample of 22 361 African ancestry men, including 11 688 prostate cancer cases. The risk allele was present only in men of West African ancestry, with an allele frequency in men that ranged from 0.40% in Ghana and 0.31% in Nigeria to 0% in Uganda and South Africa, with a range of frequencies in men with admixed African ancestry from North America and Europe (0-0.26%). HOXB13 X285K was associated with 2.4-fold increased odds of prostate cancer (95% confidence interval [CI] = 1.5-3.9, p = 2 × 10^-4), with greater risk observed for more aggressive and advanced disease (Gleason ≥8: odds ratio [OR] = 4.7, 95% CI = 2.3-9.5, p = 2 × 10^-5; stage T3/T4: OR = 4.5, 95% CI = 2.0-10.0, p = 2 × 10^-4; metastatic disease: OR = 5.1, 95% CI = 1.9-13.7, p = 0.001). We estimated that the allele arose in West Africa 1500-4600 yr ago. Further analysis is needed to understand how the HOXB13 X285K variant impacts the HOXB13 protein and function in the prostate. Understanding who carries this mutation may inform prostate cancer screening in men of West African ancestry. PATIENT SUMMARY: A rare African ancestry-specific germline deletion in HOXB13, found only in men of West African ancestry, was reported to be associated with an increased risk of overall and advanced prostate cancer. Understanding who carries this mutation may help inform screening for prostate cancer in men of West African ancestry.

Gestational diabetes and risk of breast cancer before age 55 years

BACKGROUND

The history of gestational diabetes mellitus (GDM) has been associated with breast cancer risk in some studies, particularly in young women, but results of cohort studies are conflicting.

METHODS

We pooled data from 257 290 young (age <55 years) women from five cohorts. We used multivariable Cox proportional-hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between GDM history and risk of breast cancer, overall and by oestrogen receptor (ER) status, before age 55 years, adjusted for established breast cancer risk factors.

RESULTS

Five percent of women reported a history of GDM and 6842 women reported an incident breast-cancer diagnosis (median follow-up = 16 years; maximum = 24 years). Compared with parous women without GDM, women with a history of GDM were not at increased risk of young-onset breast cancer overall (HR = 0.90; 95% CI: 0.78, 1.03) or by ER status (HR = 0.96; 95% CI: 0.79, 1.16 for ER-positive; HR = 1.07; 95% CI: 0.78, 1.47 for ER-negative). Compared with nulliparous women, parous women with a history of GDM had a lower risk of breast cancer overall (HR = 0.79; 95% CI: 0.68, 0.91) and of ER-positive (HR = 0.82; 95% CI: 0.66, 1.02) but not ER-negative (HR = 1.09; 95% CI: 0.76, 1.54) invasive breast cancer. These results were consistent with the HRs comparing parous women without GDM to nulliparous women.

CONCLUSIONS

Results of this analysis do not support the hypothesis that GDM is a risk factor for breast cancer in young women. Our findings suggest that the well-established protective effect of parity on risk of ER-positive breast cancer persists even for pregnancies complicated by GDM.

Prospective study of oral microbiome and gastric cancer risk among Asian, African American and European American populations

Colonization of specific bacteria in the human mouth was reported to be associated with gastric cancer risk. However, previous studies were limited by retrospective study designs and low taxonomic resolutions. We performed a prospective case-control study nested within three cohorts to investigate the relationship between oral microbiome and gastric cancer risk. Shotgun metagenomic sequencing was employed to characterize the microbiome in prediagnostic buccal samples from 165 cases and 323 matched controls. Associations of overall microbial richness and abundance of microbial taxa, gene families and metabolic pathways with gastric cancer risk were evaluated via conditional logistic regression. Analyses were performed within each cohort, and results were combined by meta-analyses. We found that overall microbial richness was associated with decreased gastric cancer risk, with an odds ratio (OR) per standard deviation (SD) increase in Simpson's reciprocal index of 0.77 (95% confidence interval [CI] = 0.61-0.99). Nine taxa, 38 gene families and six pathways also showed associations with gastric cancer risk at P < .05. Neisseria mucosa and Prevotella pleuritidis were enriched, while Mycoplasma orale and Eubacterium yurii were depleted among cases with ORs and 95% CIs per SD increase in centered log-ratio transformed taxa abundance of 1.31 (1.03-1.67), 1.26 (1.00-1.57), 0.74 (0.59-0.94) and 0.80 (0.65-0.98), respectively. The top two gene families (P = 3.75 × 10^-4 and 3.91 × 10^-4 ) and pathways (P = 1.75 × 10^-3 and 1.53 × 10^-3 ) associated with gastric cancer were related to the decreased risk and are involved in hexitol metabolism. Our study supports the hypothesis that oral microbiota may play a role in gastric cancer etiology.

Discovery of structural deletions in breast cancer predisposition genes using whole genome sequencing data from > 2000 women of African-ancestry

Single germline nucleotide pathogenic variants have been identified in 12 breast cancer predisposition genes, but structural deletions in these genes remain poorly characterized. We conducted in-depth whole genome sequencing (WGS) in genomic DNA samples obtained from 1340 invasive breast cancer cases and 675 controls of African ancestry. We identified 25 deletions in the intragenic regions of ten established breast cancer predisposition genes based on a consensus call from six state-of-the-art SV callers. Overall, no significant case-control difference was found in the frequency of these deletions. However, 1.0% of cases and 0.3% of controls carried any of the eight putative protein-truncating rare deletions located in BRCA1, BRCA2, CDH1, TP53, NF1, RAD51D, RAD51C and CHEK2, resulting in an odds ratio (OR) of 3.29 (95% CI 0.74-30.16). We also identified a low-frequency deletion in NF1 associated with breast cancer risk (OR 1.93, 95% CI 1.14-3.42). In addition, we detected 56 deletions, including six putative protein-truncating deletions, in suspected breast predisposition genes. This is the first large study to systematically search for structural deletions in breast cancer predisposition genes. Many of the deletions, particularly those resulting in protein truncations, are likely to be pathogenic. Results from this study, if confirmed in future large-scale studies, could have significant implications for genetic testing for this common cancer.

Adverse Childhood Experiences and Chronic Disease Risk in the Southern Community Cohort Study

We used the Southern Community Cohort Study of people residing in 12 states in the southeastern United States (n=38,200 participants) to examine associations between adverse childhood experiences (ACEs) and chronic disease risk. After adjustment for confounding, there were statistically significant positive associations for people reporting four or more ACEs relative to those reporting no ACEs, and this was true for all chronic diseases except hypertension. The most elevated risk was seen for depression when measured as a yes/no variable (odds ratio (OR) 2.84, 95% confidence interval (CI) 2.64-3.06) or when using the 10-item Center for Epidemiologic Student Depression (CESD) scale (OR 1.88, 95% CI 1.75-2.02). There were also statistically significant monotonic increases in risk with worsening ACE score for all chronic diseases except hypertension, cancer, and high cholesterol. The need to establish programs that build resilience during childhood is paramount for preventing chronic diseases that may result from childhood abuse, neglect, and household dysfunction.

Racial Differences in Hepatocellular Carcinoma Incidence and Risk Factors among a Low Socioeconomic Population

Simple Summary

Liver cancer incidence in the United States is higher among African Americans compared to White Americans. The determinants of racial disparities in liver cancer incidence are not clear. Using data from White and African Americans from low socioeconomic backgrounds, we compared the prevalence of known liver cancer risk factors by race and assessed factors associated with liver cancer incidence. Understanding liver cancer risk differences can assist prevention strategies that target people at high risk, potentially based on risk factors that differ by race.

Abstract

The purpose of this study was to examine differences in risk factors associated with hepatocellular carcinoma (HCC) among White and African Americans from low socioeconomic backgrounds in the Southern Community Cohort Study (SCCS). The SCCS is a prospective cohort study with participants from the southeastern US. HCC incidence rates were calculated. Multivariable Cox regression was used to calculate HCC-adjusted hazard ratios (aHR) associated with known baseline HCC risk factors for White and African Americans, separately. There were 294 incident HCC. The incidence rate ratio for HCC was higher (IRR = 1.4, 95%CI: 1.1–1.9) in African Americans compared to White Americans. White Americans saw a stronger association between self-reported hepatitis C virus (aHR = 19.24, 95%CI: 10.58–35.00) and diabetes (aHR = 3.55, 95%CI: 1.96–6.43) for the development of HCC compared to African Americans (aHR = 7.73, 95%CI: 5.71–10.47 and aHR = 1.48, 95%CI: 1.06–2.06, respectively) even though the prevalence of these risk factors was similar between races. Smoking (aHR = 2.91, 95%CI: 1.87–4.52) and heavy alcohol consumption (aHR = 1.59, 95%CI: 1.19–2.11) were significantly associated with HCC risk among African Americans only. In this large prospective cohort, we observed racial differences in HCC incidence and risk factors associated with HCC among White and African Americans.

Associations of Subtype and Isomeric Plasma Carotenoids with Prostate Cancer Risk in Low-Income African and European Americans

BACKGROUND

Various carotenoids in circulation, including isomers, may have different influences on cancer risk.

METHODS

We conducted a nested case-control study including 343 incident prostate cancer cases and 640 controls individually matched on age, race, study site, and time of blood collection. Carotenoids investigated were carotene, cryptoxanthin, lycopene, dihydrolycopene, lutein, anhydrolutein, and zeaxanthin, including α versus β configurations and cis versus trans isomers. General linear model and conditional logistic regression were applied to evaluate associations for prostate cancer risk, with adjustment for potential confounders. We conducted additional analyses with further stratification by race, multivitamin use, and smoking status.

RESULTS

Case-control differences were found in carotenoid subtype levels, although not all reached the multiple comparison adjusted threshold for significance. Plasma lycopene [OR_{T1 vs. T3} = 0.51; 95% confidence interval (CI), 0.29-0.87; P _trend = 0.014], dihydrolycopene (OR_{T1 vs. T3} = 0.37; 95% CI, 0.18-0.74; P _trend = 0.006), and cis-anhydrolutein (OR_{T1 vs. T3} = 0.57; 95% CI, 0.33-0.96; P _trend = 0.037) were inversely, while β-trans-carotene (OR_{T1 vs. T3} = 2.13; 95% CI, 1.32-3.43; P _trend = 0.002) and trans-lutein (OR_{T1 vs. T3}, 1.86; 95% CI, 1.20-2.88; P _trend = 0.006) were positively associated with prostate cancer risk. Stratified analyses showed inverse associations of lycopene, dihydrolycopene, and cis-anhydrolutein with prostate cancer risk in subjects without multivitamin use; lycopene and dihydrolycopene in African-Americans and current smokers; and dihydrolycopene in nonsmokers. Positive associations of β-trans-carotene and trans-lutein were observed in African-Americans, nonsmokers, and multivitamin users.

CONCLUSIONS

The associations of carotenoids with risk of prostate cancer differed by carotenoid subtypes.

IMPACT

Public health recommendations on carotenoid intakes for prostate cancer prevention should take subtypes and isomers into consideration.

Epidemiology of 40 blood biomarkers of one-carbon metabolism, vitamin status, inflammation, and renal and endothelial function among cancer-free older adults

Imbalances of blood biomarkers are associated with disease, and biomarkers may also vary non-pathologically across population groups. We described variation in concentrations of biomarkers of one-carbon metabolism, vitamin status, inflammation including tryptophan metabolism, and endothelial and renal function among cancer-free older adults. We analyzed 5167 cancer-free controls aged 40-80 years from 20 cohorts in the Lung Cancer Cohort Consortium (LC3). Centralized biochemical analyses of 40 biomarkers in plasma or serum were performed. We fit multivariable linear mixed effects models to quantify variation in standardized biomarker log-concentrations across four factors: age, sex, smoking status, and body mass index (BMI). Differences in most biomarkers across most factors were small, with 93% (186/200) of analyses showing an estimated difference lower than 0.25 standard-deviations, although most were statistically significant due to large sample size. The largest difference was for creatinine by sex, which was - 0.91 standard-deviations lower in women than men (95%CI - 0.98; - 0.84). The largest difference by age was for total cysteine (0.40 standard-deviation increase per 10-year increase, 95%CI 0.36; 0.43), and by BMI was for C-reactive protein (0.38 standard-deviation increase per 5-kg/m2 increase, 95%CI 0.34; 0.41). For 31 of 40 markers, the mean difference between current and never smokers was larger than between former and never smokers. A statistically significant (p < 0.05) association with time since smoking cessation was observed for 8 markers, including C-reactive protein, kynurenine, choline, and total homocysteine. We conclude that most blood biomarkers show small variations across demographic characteristics. Patterns by smoking status point to normalization of multiple physiological processes after smoking cessation.

Abstract LB011: Meta-analysis in more than 80,000 men of African ancestry identified nine novel variants associated with prostate cancer

In search for common genetic variants contributing to the risk of prostate cancer in men of African ancestry, we conducted a meta-analysis of GWAS summary statistics from the African Ancestry Prostate Cancer Consortium (AAPC; 12,643 cases and 16,627 controls) and the VA Million Veteran Program (6,107 cases and 47,412 controls). A total of 29,896,808 common (minor allele frequency (MAF) &gt; 0.01) genotyped and imputed variants (r2 &gt; 0.3) were meta-analyzed in a total of 18,750 prostate cancer cases and 64,039 controls. Of the 269 established risk variants for prostate cancer, 265 were polymorphic and 168 were nominally (P&lt;0.05) associated with prostate cancer risk with directionally consistent effect estimates, of which 44 reached the genome-wide significance (P&lt;5x10-8). Of the 3,018 genome-wide significant variants, eight were considered novel susceptibility loci for prostate cancer in men of African ancestry. Of the eight variants, five were only found in populations of African ancestry (MAF 2% - 34%) but not in European or Asian populations, and two were substantially more common in African ancestry populations (MAF 40%) than in other populations (MAF &lt; 8%). One of the novel variants, rs60985508 (odds ratio (OR) = 1.12 [1.08 - 1.15]; P = 2.93×10-13; MAF = 34%), introduces a stop codon in exon 24 in the prostate-specific gene anoctamin 7 (ANO7), a known prostate cancer susceptibility gene. A polygenic risk score including 273 variants (265 of 269 established risk variants and 8 novel variants from this analysis) conferred an increased prostate cancer risk for men in the 90 - 100th percentile (OR = 3.91 [3.50 - 4.36]) and those in the 99 - 100th percentile (OR = 7.05 [5.51 - 9.02]), compared to men in the 40-60th percentile. These estimates were higher than what was observed with the PRS of 265 variants (90 - 100th percentile: OR = 3.49 [3.13 - 3.90]; 99 - 100th percentile: OR = 6.40 [4.99 - 8.21]). Our finding of 8 novel susceptibility loci for prostate cancer may improve risk prediction for men of African Ancestry and provide further insight into the underlying biology of prostate cancer.

Citation Format: Fei Chen, Ravi K. Madduri, Xin Sheng, Alex Rodriguez, Alisha Chou, Todd L. Edwards, Stephen K. Van Den Eeden, Rosalind A. Eeles, John S. Witte, Michael B. Cook, William J. Blot, David V. Conti, John M. Gaziano, Amy C. Justice, Christopher A. Haiman, VA Million Veteran Program and PRACTICAL/ELLIPSE Consortium. Meta-analysis in more than 80,000 men of African ancestry identified nine novel variants associated with prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB011.

Cholesterol and Egg Intakes with Cardiometabolic and All-Cause Mortality among Chinese and Low-Income Black and White Americans

We examined the associations of dietary cholesterol and egg intakes with cardiometabolic and all-cause mortality among Chinese and low-income Black and White Americans. Included were 47,789 Blacks, 20,360 Whites, and 134,280 Chinese aged 40–79 years at enrollment. Multivariable Cox models with restricted cubic splines were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality outcomes using intakes of 150 mg cholesterol/day and 1 egg/week as the references. Cholesterol intake showed a nonlinear association with increased all-cause mortality and a linear association with increased cardiometabolic mortality among Black Americans: HRs (95% CIs) associated with 300 and 600 mg/day vs. 150 mg/day were 1.07 (1.03–1.11) and 1.13 (1.05–1.21) for all-cause mortality (P-linearity = 0.04, P-nonlinearity = 0.002, and P-overall < 0.001) and 1.10 (1.03–1.16) and 1.21 (1.08–1.36) for cardiometabolic mortality (P-linearity = 0.007, P-nonlinearity = 0.07, and P-overall = 0.005). Null associations with all-cause or cardiometabolic mortality were noted for White Americans (P-linearity ≥ 0.13, P-nonlinearity ≥ 0.06, and P-overall ≥ 0.05 for both). Nonlinear inverse associations were observed among Chinese: HR (95% CI) for 300 vs. 150 mg/day was 0.94 (0.92–0.97) for all-cause mortality and 0.91 (0.87–0.95) for cardiometabolic mortality, but the inverse associations disappeared with cholesterol intake > 500 mg/day (P-linearity ≥ 0.12; P-nonlinearity ≤ 0.001; P-overall < 0.001 for both). Similarly, we observed a positive association of egg intake with all-cause mortality in Black Americans, but a null association in White Americans and a nonlinear inverse association in Chinese. In conclusion, the associations of cholesterol and egg intakes with cardiometabolic and all-cause mortality may differ across ethnicities who have different dietary patterns and cardiometabolic risk profiles. However, residual confounding remains possible.

Abstract MP31: Early Age At Menopause And The Association With Incident Heart Failure In The Southern Community Cohort Study

Introduction: Reproductive factors might have an effect on the development of heart failure (HF). Early age at menopause has been linked with increased risk of cardiovascular disease; however, there is limited evidence on the relationship between early menopause and HF.

Hypothesis: We assessed the hypothesis that earlier age at menopause is associated with increased risk of incident HF among women in the southeastern United States.

Methods: The Southern Community Cohort Study enrolled ~86,000 low-income black and white adults in 12 southeastern states (2002-2009). Participants for this analysis were 11,948 women who were postmenopausal at enrollment, had no history of HF, and were using Centers for Medicare or Medicaid Services (CMS). HF events were ascertained using International Classification of Diseases , Ninth Revision, codes 428.x via linkage of the cohort with CMS Research Identifiable Files through December 31, 2016. Early menopause was defined as self-reported age at menopause less than 45 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed from multivariable Cox regression models, overall and by race, adjusting for demographic, lifestyle, and reproductive factors, including reason for menopause.

Results: At baseline, median age was 58 years and 65% of participants were black. Among women with early menopause, 76% (n=4,836) had menopause due to hysterectomy or oophorectomy. In women with later menopause, 74% (n=4,102) reported natural menopause. During a median follow-up of 9.5 years (interquartile range 6.0-11.8), 3,808 incident HF events occurred. Compared to women with later onset of menopause, those with early menopause had increased HF risk (HR: 1.13, 95% CI: 1.04-1.23). Risk of HF associated with early menopause differed between white and black women (p-value for interaction: 0.02). In stratified analyses, white women with early menopause had an increased risk of HF compared to those with later onset of menopause (HR: 1.26, 95% CI: 1.11-1.43), although there was no association between early age at menopause and risk of HF in black women (HR: 1.07, 95% CI: 0.98-1.18).

Conclusions: In conclusion, in this largely low-income population, early menopause is associated with an increased risk of developing HF and associations differ by race. Women with early menopause represent a potential target population for future interventions aimed to decrease risk of HF and cardiovascular risk factors.

Associations of coffee and tea consumption with lung cancer risk

Associations of coffee and tea consumption with lung cancer risk have been inconsistent, and most lung cancer cases investigated were smokers. Included in this study were over 1.1 million participants from 17 prospective cohorts. Cox regression analyses were conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Potential effect modifications by sex, smoking, race, cancer subtype and coffee type were assessed. After a median 8.6 years of follow-up, 20 280 incident lung cancer cases were identified. Compared with noncoffee and nontea consumption, HRs (95% CIs) associated with exclusive coffee drinkers (≥2 cups/d) among current, former and never smokers were 1.30 (1.15-1.47), 1.49 (1.27-1.74) and 1.35 (1.15-1.58), respectively. Corresponding HRs for exclusive tea drinkers (≥2 cups/d) were 1.16 (1.02-1.32), 1.10 (0.92-1.32) and 1.37 (1.17-1.61). In general, the coffee and tea associations did not differ significantly by sex, race or histologic subtype. Our findings suggest that higher consumption of coffee or tea is associated with increased lung cancer risk. However, these findings should not be assumed to be causal because of the likelihood of residual confounding by smoking, including passive smoking, and change of coffee and tea consumption after study enrolment.

A Pooled Case-only Analysis of Reproductive Risk Factors and Breast Cancer Subtype Among Black Women in the Southeastern United States

BACKGROUND

We investigated the association between reproductive risk factors and breast cancer subtype in Black women. On the basis of the previous literature, we hypothesized that the relative prevalence of specific breast cancer subtypes might differ according to reproductive factors.

METHODS

We conducted a pooled analysis of 2,188 (591 premenopausal, 1,597 postmenopausal) Black women with a primary diagnosis of breast cancer from four studies in the southeastern United States. Breast cancers were classified by clinical subtype. Case-only polytomous logistic regression models were used to estimate ORs and 95% confidence intervals (CI) for HER2⁺ and triple-negative breast cancer (TNBC) status in relation to estrogen receptor-positive (ER⁺)/HER2^- status (referent) for reproductive risk factors.

RESULTS

Relative to women who had ER⁺/HER2^- tumors, women who were age 19-24 years at first birth (OR, 1.78; 95% CI, 1.22-2.59) were more likely to have TNBC. Parous women were less likely to be diagnosed with HER2⁺ breast cancer and more likely to be diagnosed with TNBC relative to ER⁺/HER2^- breast cancer. Postmenopausal parous women who breastfed were less likely to have TNBC [OR, 0.65 (95% CI, 0.43-0.99)].

CONCLUSIONS

This large pooled study of Black women with breast cancer revealed etiologic heterogeneity among breast cancer subtypes.

IMPACT

Black parous women who do not breastfeed are more likely to be diagnosed with TNBC, which has a worse prognosis, than with ER⁺/HER2^- breast cancer.

Red meat consumption, cooking mutagens, NAT1/2 genotypes and pancreatic cancer risk in two ethnically diverse prospective cohorts

There is limited evidence on the association between red meat consumption and pancreatic cancer among ethnic minorities. We assessed this relationship in two large prospective cohorts: the Multiethnic Cohort Study (MEC) and the Southern Community Cohort Study (SCCS). Demographic, dietary and other risk factor data were collected at cohort entry. Red meat intake was assessed using cohort-specific validated food frequency questionnaires. Incident pancreatic cancer cases were identified via linkages to state cancer registries. Cox regression was used to calculate relative risks (RRs) and 95% confidence intervals (CIs) for the association of red meat intake with pancreatic cancer risk in each cohort. We performed additional analyses to evaluate cooking methods, mutagens and effect modification by NAT1/2 genotypes. From a total of 184 542 (MEC) and 66 793 (SCCS) at-risk participants, we identified 1618 (MEC) and 266 (SCCS) incident pancreatic cancer cases. Red meat consumption was associated with pancreatic cancer risk in the MEC (RRQ4vsQ1 1.18, 95% CI 1.02-1.37) and with borderline statistical significance in the SCCS (RRQ4vsQ1 1.31, 95% CI 0.93-1.86). This association was significant in African Americans (RRQ4vsQ1 1.49, 95% CI 1.06-2.11) and Latinos (RRQ4vsQ1 1.44, 95% CI 1.02-2.04) in the MEC, and among African Americans (RRQ4vsQ1 1.55, 95% CI 1.03-2.33) in the SCCS. NAT2 genotypes appeared to modify the relationship between red meat and pancreatic cancer in the MEC (pinteraction = 0.03). Our findings suggest that the associations for red meat may be strongest in African Americans and Latinos. The mechanisms underlying the increased risk for these populations should be further investigated.

Association between lincRNA expression and overall survival for patients with triple-negative breast cancer

PURPOSE

Long intergenic non-coding RNAs (lincRNAs) are increasingly recognized as important regulators for pathogenesis and/or prognosis of breast cancer, including triple-negative breast cancer (TNBC) subtype. However, few previous studies used RNA-sequencing (RNA-Seq) technology, and none included an independent replication.

METHODS

To systematically evaluate the association between expression of lincRNAs and TNBC survival, we examined lincRNA expression profiles in TNBC tissues using RNA-Seq data for 200 TNBC patients from the Shanghai Breast Cancer Survival Study (SBCSS) and Southern Community Cohort Study (SCCS).

RESULTS

Twenty-five lincRNAs were found to be associated with overall survival (P < 0.05 and no significant heterogeneity across studies at Q statistic P > 0.1), and 61 lincRNAs were associated with disease-free survival (DFS). Among these, two lincRNAs (LINC01270 and LINC00449) were significantly associated with both worse overall survival and DFS and were expressed at significantly higher levels in tumor tissues compared with adjacent normal breast tissues (log2[Fold Change] > 0.5 and FDR < 0.05). We further evaluated the potential functions of LINC01270 and LINC00449 using in vitro functional experiments and found that siRNA-mediated knockdown of LINC01270 and LINC00449 expression significantly decreased cell viability, colony formation and cell migration ability in TNBC cells (P < 0.05).

CONCLUSIONS

Evidence from observational studies and in vitro experiments indicates that LINC00449 and LINC01270 may be prognostic biomarkers for TNBC.

Prediagnostic Antibody Responses to Fusobacterium nucleatum Proteins Are Not Associated with Risk of Colorectal Cancer in a Large U.S. Consortium

BACKGROUND

The association between prediagnostic antibody responses to Fusobacterium nucleatum (F. nucleatum) and subsequent risk of colorectal cancer is not established.

METHODS

We conducted a nested case-control study of 8,126 participants in a consortium of 10 prospective cohorts in the United States.

RESULTS

Higher seroprevalence of any F. nucleatum antibody was observed among non-White participants (51.1%) compared with White participants (31.2%). We did not find any statistically significant association between seropositivity to any of the eight F. nucleatum proteins and colorectal cancer risk.

CONCLUSIONS

Prediagnostic antibody responses to F. nucleatum proteins were not associated with the risk of colorectal cancer.

IMPACT

Future studies may consider a more specific detection of the immunoglobulin isotypes or focus on examining F. nucleatum in stool or tissue samples.

Diabetes and liver cancer risk: A stronger effect in Whites than Blacks?

BACKGROUND

Both diabetes and liver cancer are overrepresented among African Americans, but limited information is available on the interrelationship of these two diseases among African Americans. We examined the association of diabetes with the incidence of liver cancer and whether this varied by participant self-reported race/ethnicity.

METHODS

Using the Southern Community Cohort Study, we conducted a cancer follow up (2002-2016) of a cohort of mostly low-income participants aged 40-79 with diabetes (n = 15,879) and without diabetes (n = 59,077) at study baseline. Cox regression was used to compute Hazard Ratios (HR) and 95% CIs for the risk of incident liver cancer.

RESULTS

With 790,132 person years of follow up, 320 incident cases of liver cancer were identified. In analyses controlling for age, sex, race, BMI, current and former smoking, total alcohol consumption, family history of liver cancer, any hepatitis infection, hyperlipidemia and socioeconomic factors, the association between diabetes and risk of liver cancer differed significantly (p_interaction = 0.0001) between participants identifying as Black/African American (AA) or White/European American (EA). Diabetes was associated with 5.3-fold increased cancer risk among EAs (HR 5.4, 95% CI 3.2-9.3) vs an 80% increase (HR 1.8, 95% CI 1.3-2.5) among AAs. Furthermore, controlling for diabetes greatly attenuated the higher risk of liver cancer among AAs; indeed, while the cancer risk among those without diabetes was twice as high among AAs than EAs (HR = 2.0, 95% CI = 1.4-2.9), no excess in AAs was observed among those with diabetes (HR = 0.7, 95% CI = 0.4-1.1).

CONCLUSION

While liver cancer risk in general is greater in AAs than EAs and diabetes increases this risk in both racial/ethnic groups, diabetes appears to impact liver cancer to a much greater extent among EAs. The findings raise the possibility of racially different mechanisms and impacts of diabetes on this often fatal cancer among AAs and EAs.

Polygenic hazard score is associated with prostate cancer in multi-ethnic populations

Genetic models for cancer have been evaluated using almost exclusively European data, which could exacerbate health disparities. A polygenic hazard score (PHS1) is associated with age at prostate cancer diagnosis and improves screening accuracy in Europeans. Here, we evaluate performance of PHS2 (PHS1, adapted for OncoArray) in a multi-ethnic dataset of 80,491 men (49,916 cases, 30,575 controls). PHS2 is associated with age at diagnosis of any and aggressive (Gleason score ≥ 7, stage T3-T4, PSA ≥ 10 ng/mL, or nodal/distant metastasis) cancer and prostate-cancer-specific death. Associations with cancer are significant within European (n = 71,856), Asian (n = 2,382), and African (n = 6,253) genetic ancestries (p < 10-180). Comparing the 80th/20th PHS2 percentiles, hazard ratios for prostate cancer, aggressive cancer, and prostate-cancer-specific death are 5.32, 5.88, and 5.68, respectively. Within European, Asian, and African ancestries, hazard ratios for prostate cancer are: 5.54, 4.49, and 2.54, respectively. PHS2 risk-stratifies men for any, aggressive, and fatal prostate cancer in a multi-ethnic dataset.