Using genome and transcriptome data from African-ancestry female participants to identify putative breast cancer susceptibility genes

African-ancestry (AA) participants are underrepresented in genetics research. Here, we conducted a transcriptome-wide association study (TWAS) in AA female participants to identify putative breast cancer susceptibility genes. We built genetic models to predict levels of gene expression, exon junction, and 3' UTR alternative polyadenylation using genomic and transcriptomic data generated in normal breast tissues from 150 AA participants and then used these models to perform association analyses using genomic data from 18,034 cases and 22,104 controls. At Bonferroni-corrected P < 0.05, we identified six genes associated with breast cancer risk, including four genes not previously reported (CTD-3080P12.3, EN1, LINC01956 and NUP210L). Most of these genes showed a stronger association with risk of estrogen-receptor (ER) negative or triple-negative than ER-positive breast cancer. We also replicated the associations with 29 genes reported in previous TWAS at P < 0.05 (one-sided), providing further support for an association of these genes with breast cancer risk. Our study sheds new light on the genetic basis of breast cancer and highlights the value of conducting research in AA populations.

Psychosocial stressors and breast cancer gene expression in the Black Women's Health Study

PURPOSE

Prior studies indicate that the physiologic response to stress can affect gene expression. We evaluated differential gene expression in breast cancers collected from Black women with high versus low exposure to psychosocial stressors.

METHODS

We analyzed tumor RNA sequencing data from 417 Black Women's Health Study breast cancer cases with data on early life trauma and neighborhood disadvantage. We conducted age-adjusted differential gene expression analyses and pathway analyses. We also evaluated Conserved Transcriptional Response to Adversity (CTRA) contrast scores, relative fractions of immune cell types, T cell exhaustion, and adrenergic signaling. Analyses were run separately for estrogen receptor positive (ER+; n = 299) and ER- (n = 118) cases.

RESULTS

Among ER+ cases, the top differentially expressed pathways by stress exposure were related to RNA and protein metabolism. Among ER- cases, they were related to developmental biology, signal transduction, metabolism, and the immune system. Targeted analyses indicated greater immune pathway enrichment with stress exposure for ER- cases, and possible relevance of adrenergic signaling for ER+ cases. CTRA contrast scores did not differ by stress exposure, but in analyses of the CTRA components, ER- breast cancer cases with high neighborhood disadvantage had higher pro-inflammatory gene expression (p = 0.039) and higher antibody gene expression (p = 0.006) compared to those with low neighborhood disadvantage.

CONCLUSION

There are multiple pathways through which psychosocial stress exposure may influence breast tumor biology. Given the present findings on inflammation and immune response in ER- tumors, further research to identify stress-induced changes in the etiology and progression of ER- breast cancer is warranted.

Reproductive risk factors for breast cancer and association with novel breast density measurements among Hispanic, Black, and White women

PURPOSE

There are differences in the distributions of breast cancer incidence and risk factors by race and ethnicity. Given the strong association between breast density and breast cancer, it is of interest describe racial and ethnic variation in the determinants of breast density.

METHODS

We characterized racial and ethnic variation in reproductive history and several measures of breast density for Hispanic (n = 286), non-Hispanic Black (n = 255), and non-Hispanic White (n = 1694) women imaged at a single hospital. We quantified associations between reproductive factors and percent volumetric density (PVD), dense volume (DV), non-dense volume (NDV), and a novel measure of pixel intensity variation (V) using multivariable-adjusted linear regression, and tested for statistical heterogeneity by race and ethnicity.

RESULTS

Reproductive factors most strongly associated with breast density were age at menarche, parity, and oral contraceptive use. Variation by race and ethnicity was most evident for the associations between reproductive factors and NDV (minimum p-heterogeneity:0.008) and V (minimum p-heterogeneity:0.004) and least evident for PVD (minimum p-heterogeneity:0.042) and DV (minimum p-heterogeneity:0.041).

CONCLUSION

Reproductive choices, particularly those related to childbearing and oral contraceptive use, may contribute to racial and ethnic variation in breast density.

Molecular subtypes of high-grade serous ovarian cancer across racial groups and gene expression platforms

Introduction

High-grade serous carcinoma (HGSC) gene expression subtypes are associated with differential survival. We characterized HGSC gene expression in Black individuals and considered whether gene expression differences by race may contribute to poorer HGSC survival among Black versus non-Hispanic White individuals.

Methods

We included newly generated RNA-Seq data from Black and White individuals, and array-based genotyping data from four existing studies of White and Japanese individuals. We assigned subtypes using K-means clustering. Cluster- and dataset-specific gene expression patterns were summarized by moderated t-scores. We compared cluster-specific gene expression patterns across datasets by calculating the correlation between the summarized vectors of moderated t-scores. Following mapping to The Cancer Genome Atlas (TCGA)-derived HGSC subtypes, we used Cox proportional hazards models to estimate subtype-specific survival by dataset.

Results

Cluster-specific gene expression was similar across gene expression platforms. Comparing the Black study population to the White and Japanese study populations, the immunoreactive subtype was more common (39% versus 23%-28%) and the differentiated subtype less common (7% versus 22%-31%). Patterns of subtype-specific survival were similar between the Black and White populations with RNA-Seq data; compared to mesenchymal cases, the risk of death was similar for proliferative and differentiated cases and suggestively lower for immunoreactive cases (Black population HR=0.79 [0.55, 1.13], White population HR=0.86 [0.62, 1.19]).

Conclusions

A single, platform-agnostic pipeline can be used to assign HGSC gene expression subtypes. While the observed prevalence of HGSC subtypes varied by race, subtype-specific survival was similar.

Menopausal hormone therapy use and risk of ovarian cancer by race: the ovarian cancer in women of African ancestry consortium

BACKGROUND

Most studies examining post-menopausal menopausal hormone therapy (MHT) use and ovarian cancer risk have focused on White women and few have included Black women.

METHODS

We evaluated MHT use and ovarian cancer risk in Black (n = 800 cases, 1783 controls) and White women (n = 2710 cases, 8556 controls), using data from the Ovarian Cancer in Women of African Ancestry consortium. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association of MHT use with ovarian cancer risk, examining histotype, MHT type and duration of use.

RESULTS

Long-term MHT use, ≥10 years, was associated with an increased ovarian cancer risk for White women (OR = 1.38, 95%CI: 1.22-1.57) and the association was consistent for Black women (OR = 1.20, 95%CI: 0.81-1.78, pinteraction = 0.4). For White women, the associations between long-term unopposed estrogen or estrogen plus progesterone use and ovarian cancer risk were similar; the increased risk associated with long-term MHT use was confined to high-grade serous and endometroid tumors. Based on smaller numbers for Black women, the increased ovarian cancer risk associated with long-term MHT use was apparent for unopposed estrogen use and was predominately confined to other epithelial histotypes.

CONCLUSION

The association between long-term MHT use and ovarian cancer risk was consistent for Black and White women.

Impact of age, race, and family history on COVID-19-related changes in breast cancer screening among the Boston mammography cohort study

PURPOSE

We studied women enrolled in the Boston Mammography Cohort Study to investigate whether subgroups defined by age, race, or family history of breast cancer experienced differences in the incidence of screening or diagnostic imaging rates during the COVID-19 lockdown and had slower rebound in the incidence of these rates during reopening.

METHODS

We compared the incidence of monthly breast cancer screening and diagnostic imaging rates over during the pre-COVID-19 (January 2019-February 2020), lockdown (March-May 2020), and reopening periods (June-December 2020), and tested for differences in the monthly incidence within the same period by age (< 50 vs ≥ 50), race (White vs non-White), and first-degree family history of breast cancer (yes vs no).

RESULTS

Overall, we observed a decline in breast cancer screening and diagnostic imaging rates over the three time periods (pre-COVID-19, lockdown, and reopening). The monthly incidence of breast cancer screening rates for women age ≥ 50 was 5% higher (p = 0.005) in the pre-COVID-19 period (January 2019-February 2020) but was 19% lower in the reopening phase (June-December 2020) than that of women aged < 50 (p < 0.001). White participants had 36% higher monthly incidence of breast cancer diagnostic imaging rates than non-White participants (p = 0.018).

CONCLUSION

The rebound in screening was lower in women age ≥ 50 and lower in non-White women for diagnostic imaging. Careful attention must be paid as the COVID-19 recovery continues to ensure equitable resumption of care.

Pathways to lung cancer diagnosis among individuals who did not receive lung cancer screening: a qualitative study

BACKGROUND

Although early detection of lung cancer through screening is associated with better prognosis, most lung cancers are diagnosed among unscreened individuals. We therefore sought to characterize pathways to lung cancer diagnosis among unscreened individuals.

METHODS

Participants were individuals with lung cancer who did not undergo asymptomatic lung cancer screening (n = 13) and healthcare providers who may be involved in the pathway to lung cancer diagnosis (n = 13). We conducted semi-structured interviews to identify themes in lung cancer patients' narratives of their cancer diagnoses and providers' personal and/or professional experiences of various pathways to lung cancer diagnoses, to identify delays in diagnosis. We audio-recorded, transcribed, and coded interviews in two stages. First, we conducted deductive coding using three time-period intervals from the Models of Pathways to Treatment framework: appraisal, help-seeking, and diagnostic (i.e., excluding pre-treatment). Second, we conducted inductive coding to identify themes within each time-period interval, and classified these themes as either barriers or facilitators to diagnosis. Coding and thematic summarization were completed independently by two separate analysts who discussed for consensus.

RESULTS

Eight of the patient participants had formerly smoked, and five had never smoked. We identified eight barrier/facilitator themes within the three time-period intervals. Within the appraisal interval, the barrier theme was (1) minimization or misattribution of symptoms, and the facilitator theme was (2) acknowledgment of symptoms. Within the help-seeking interval, the barrier theme was (3) hesitancy to seek care, and the facilitator theme was (4) routine care. Within the diagnosis interval, barrier themes were (5) health system challenges, and (6) social determinants of health; and facilitator themes were (7) severe symptoms and known risk factors, and (8) self-advocacy. Many themes were interrelated, including minimization or misattribution of symptoms and hesitancy to seek care, which may collectively contribute to care and imaging delays.

CONCLUSIONS

Interventions to reduce hesitancy to seek care may facilitate timely lung cancer diagnoses. More prompt referral to imaging-especially computed tomography (CT)-among symptomatic patients, along with patient self-advocacy for imaging, may reduce delays in diagnosis.

Abstract 3007: Psychosocial stressors and breast cancer gene expression in the Black Women's Health Study

Introduction: Chronic sympathetic nervous system (SNS) activation following exposure to psychosocial stressors may influence cancer risk through dysregulation of immune function or adrenergic signaling pathways. Prior research out of the Black Women’s Health Study (BWHS) reported associations between psychosocial stressors and breast cancer risk. We hypothesized that women with greater exposure to psychosocial stressors before their breast cancer diagnosis have higher tumor gene expression of immune-related and adrenergic signaling pathways.

Methods: The BWHS is a large, prospective cohort study that has collected health and lifestyle information biennially since 1995. We included data from 417 BWHS breast cancer cases with RNA sequencing data and information on early-life trauma and neighborhood disadvantage. We used the R package DESeq2 to conduct age-adjusted differential gene expression analyses by levels of each stress exposure and described the top differentially expressed pathways using the Molecular Signature Database REACTOME subset of canonical pathways. Targeted analyses of immune-related pathways used CIBERSORT to quantify the proportions of infiltrating immune cells and the R package GSVA for single-sample gene set enrichment analysis (ssGSEA) of genes comprising a T cell exhaustion signature. We also used ssGSEA to evaluate a set of genes involved in adrenergic signaling. Given the variability in gene expression for ER+ versus ER- breast cancers, all analyses were run separately for ER+ (n=299) and ER- (n=118) tumors.

Results: Pathways related to nervous system development and the metabolism of RNA were differentially expressed by levels of stress exposures among ER+ and ER- cases, while pathways related to immune function and adrenergic signaling were differentially expressed only among ER- cases, and only when evaluating differential gene expression by levels of neighborhood disadvantage. Targeted analyses of tumor immune infiltration showed significantly higher B cell fractions among ER+ cases without exposure to early trauma compared to those with early trauma. The relative fractions of other immune cells did not differ by stress exposure for ER+ or ER- tumors. Findings from ssGSEA gene set analyses indicated similar expression of genes involved in T cell exhaustion and adrenergic signaling pathways by stress exposure levels for both ER+ and ER- breast cancers.

Conclusions: Our findings provide evidence of differential gene expression by levels of stress exposure; however, the differential expression may be driven by multiple pathways and not just the hypothesized immune-related and adrenergic signaling pathways. Additional studies are needed to describe mechanisms by which psychosocial stressors may influence breast cancer risk, both overall and by gene expression profile.

Citation Format: Mollie E. Barnard, Xutao Wang, Jessica L. Petrick, W. Evan Johnson, Julie R. Palmer. Psychosocial stressors and breast cancer gene expression in the Black Women's Health 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 3007.

Familial risk of epithelial ovarian cancer after accounting for gynaecological surgery: a population-based study

BACKGROUND

Uptake of risk-reducing surgery has increased among women at high risk of epithelial ovarian cancer. We sought to characterise familial risk of epithelial ovarian cancer histotypes in a population-based study after accounting for gynaecological surgeries, including bilateral oophorectomy.

METHODS

We compared risk of epithelial ovarian cancer in relatives of 3536 epithelial ovarian cancer cases diagnosed in 1966-2016 and relatives of 35 326 matched controls. We used Cox competing risk models, incorporating bilateral oophorectomy as a competing risk, to estimate the relative risk of ovarian cancer in first-degree (FDR), second-degree (SDR) and third-degree (TDR) relatives from 1966 to 2016. We also estimated relative risks in time periods before (1966-1994, 1995-2004) and after (2005-2016) formal recommendations were made for prophylactic oophorectomy among women with pathogenic variants in BRCA1/2.

RESULTS

The relative risks of epithelial ovarian cancer in FDRs, SDRs and TDRs of cases versus controls were 1.68 (95% CI 1.39 to 2.04), 1.51 (95% CI 1.30 to 1.75) and 1.34 (95% CI 1.20 to 1.48), respectively. Relative risks were greatest for high-grade serous, mucinous and 'other epithelial' histotypes. Relative risks were attenuated for case FDRs, but not for SDRs or TDRs, from 2005 onwards, consistent with the timing of recommendations for prophylactic surgery.

CONCLUSION

Familial risk of epithelial ovarian cancer extends to TDRs, especially for high-grade serous and mucinous histotypes. Distant relatives share genes but minimal environment, highlighting the importance of germline inherited genetics in ovarian cancer aetiology. Increased ovarian cancer risk in distant relatives has implications for counselling and recommendations for prophylactic surgeries that, from our data, appear only to reach FDRs.

Pathways to ovarian cancer diagnosis: a qualitative study

Background

Ovarian cancer is often diagnosed at a late stage, when survival is poor. Qualitative narratives of patients’ pathways to ovarian cancer diagnoses may identify opportunities for earlier cancer detection and, consequently, earlier stage at diagnosis.

Methods

We conducted semi-structured interviews of ovarian cancer patients and survivors (n = 14) and healthcare providers (n = 11) between 10/2019 and 10/2021. Interviews focused on the time leading up to an ovarian cancer diagnosis. Thematic analysis was conducted by two independent reviewers using a two-phase deductive and inductive coding approach. Deductive coding used a priori time intervals from the validated Model of Pathways to Treatment (MPT), including self-appraisal and management of symptoms, medical help-seeking, diagnosis, and pre-treatment. Inductive coding identified common themes within each stage of the MPT across patient and provider interviews.

Results

The median age at ovarian cancer diagnosis was 61.5 years (range, 29–78 years), and the majority of participants (11/14) were diagnosed with advanced-stage disease. The median time from first symptom to initiation of treatment was 2.8 months (range, 19 days to 4.7 years). The appraisal and help-seeking intervals contributed the greatest delays in time-to-diagnosis for ovarian cancer. Nonspecific symptoms, perceptions of health and aging, avoidant coping strategies, symptom embarrassment, and concerns about potential judgment from providers prolonged the appraisal and help-seeking intervals. Patients and providers also emphasized access to care, including financial access, as critical to a timely diagnosis.

Conclusion

Interventions are urgently needed to reduce ovarian cancer morbidity and mortality. Population-level screening remains unlikely to improve ovarian cancer survival, but findings from our study suggest that developing interventions to improve self-appraisal of symptoms and reduce barriers to help-seeking could reduce time-to-diagnosis for ovarian cancer. Affordability of care and insurance may be particularly important for ovarian cancer patients diagnosed in the United States.

Body Mass Index and Mammographic Density in a Multiracial and Multiethnic Population-Based Study

BACKGROUND

Mammographic density (MD) is strongly associated with breast cancer risk. We examined whether body mass index (BMI) partially explains racial and ethnic variation in MD.

METHODS

We used multivariable Poisson regression to estimate associations between BMI and binary MD [Breast Imaging Reporting and Database System (BI-RADS) A&B versus BI-RADS C&D] among 160,804 women in the Utah mammography cohort. We estimated associations overall and within racial and ethnic subgroups and calculated population attributable risk percents (PAR%).

RESULTS

We observed the lowest BMI and highest MD among Asian women, the highest BMI among Native Hawaiian and Pacific Islander women, and the lowest MD among American Indian and Alaska Native (AIAN) and Black women. BMI was inversely associated with MD [RRBMI≥30 vs. BMI<25 = 0.43; 95% confidence interval (CI), 0.42-0.44] in the full cohort, and estimates in all racial and ethnic subgroups were consistent with this strong inverse association. For women less than 45 years of age, although there was statistical evidence of heterogeneity in associations between BMI and MD by race and ethnicity (P = 0.009), magnitudes of association were similar across groups. PAR%s for BMI and MD among women less than 45 years were considerably higher in White women (PAR% = 29.2, 95% CI = 28.4-29.9) compared with all other groups with estimates ranging from PAR%Asain = 17.2%; 95% CI, 8.5 to 25.8 to PAR%Hispanic = 21.5%; 95% CI, 19.4 to 23.6. For women ≥55 years, PAR%s for BMI and MD were highest among AIAN women (PAR% = 37.5; 95% CI, 28.1-46.9).

CONCLUSIONS

While we observed substantial differences in the distributions of BMI and MD by race and ethnicity, associations between BMI and MD were generally similar across groups.

IMPACT

Distributions of BMI and MD may be important contributors to breast cancer disparities.

Abstract 30: A pedigree-based approach to ovarian cancer risk variant discovery in the Utah Population Database

Introduction: Genetic risk variants are critical to risk prediction for invasive epithelial ovarian cancer (EOC), yet an estimated 50-55% of EOC heritability remains missing. Novel approaches to risk variant discovery are needed to detect variants that have not been uncovered by linkage analysis or genome-wide association studies (GWAS). We approach risk variant discovery using Shared Genomic Segment analysis (SGS), a novel statistical genetics method that enables risk variant discovery in extended high-risk pedigrees.

Methods: The Utah Population Database (UPDB) is a population-based resource of over ten million individuals connected to the state of Utah, five million of whom are linked to a minimum of three generations of genealogy data. By linking this genealogy data with cancer data from the Utah Cancer Registry, we identified pedigrees with an excess risk of EOC. We generated germline genotyping data from cases (diagnosed 1983-2018) in a subset of these high-risk pedigrees, focusing on pedigrees well-suited for SGS (i.e., at least 3 cases separated by a total of at least 12 meioses). SGS identifies all runs of consecutive alleles that are shared identical-by-state by cases in a pedigree and determines which of these genomic segments are longer than would be expected by chance. These long segments are likely to be identical-by-descent, inherited from a common founder, and may harbor risk variants.

Results: We successfully linked UPDB genealogy data to information from the Utah Cancer Registry to identify approximately 2,000 extended high-risk pedigrees with ≥5 ovarian cancer cases, an average of 7-10 meioses between pairs cases, and a statistically significant excess risk of ovarian cancer (α=0.05). We obtained biospecimens for 141 cases in 36 of the most promising pedigrees (i.e., high familial standardized incidence ratio, p-value&lt;0.005, not attributable to known risk variants in BRCA1 or BRCA2 as observed in first-, second- or third-degree relatives of EOC cases). We genotyped 96 out of the 141 cases in these pedigrees (68%). SGS analyses to identify genomic regions that may harbor risk variants are currently underway.

Conclusions: Using pedigrees identified in the UPBD, SGS has identified risk loci and novel risk variants for a number of diseases, including breast and hematologic cancers. We have identified a set of EOC high-risk pedigrees for SGS analysis and will leverage SGS to identify genomic regions that may harbor EOC risk variants.

Citation Format: Mollie E. Barnard, Robert Sargent, G. Bryce Christensen, Bonita A. Mahaffey, James Albro, Elke A. Jarboe, Terence Rhodes, Nicola J. Camp, Jennifer A. Doherty. A pedigree-based approach to ovarian cancer risk variant discovery in the Utah Population Database [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 30.

Abstract 32: Body mass index and mammographic density by race and ethnicity

Background: Women with high breast density have a 4-6 fold increased risk of breast cancer compared to women with low breast density. There is a strong inverse association between body mass index (BMI) and breast density, so we hypothesized that some of the racial/ethnic variation in mammographic density may reflect differences in the prevalence of high BMI or the strength of the association between BMI and mammographic density by race/ethnicity.

Methods: We leveraged data from the Utah Population Database (UPDB) mammography cohort, including 140,200 non-Hispanic White (NHW) women, 703 non-Hispanic Black (NHB) women, 15,560 Hispanic women, 713 American Indian/Alaskan Native (AIAN) women, 2,525 Asian women, and 434 Native Hawaiian/Pacific Islander (NHPI) women with a screening mammogram obtained 2005-2019. We estimated the association between BMI and binary mammographic density (BI-RADS A & B versus C & D) using logistic regression adjusted for age, education, and parity in Utah. Menopausal status was not available, so we used age 55 as a proxy. We considered effect modification by running stratified analyses and conducting a likelihood ratio test of models with and without an interaction between BMI and race/ethnicity. We also calculated population attributable risks (PAR%).

Results: The prevalence of high BMI differed by race/ethnicity with the highest BMI among NHPI women (29.4% overweight and 52.2% obese) and lowest BMI among Asian women (17.9% overweight and 5.7% obese). Results from multivariable models were consistent with a strong inverse association between BMI and mammographic density (ORBMI&gt;30v≤25=0.21, 95% CI=0.21-0.22, p-trend &lt;0.001) that did not differ by race/ethnicity (p=0.07). There was also no evidence of heterogeneity by racial/ethnic group among women aged &lt;55 (p=0.15), but some evidence of heterogeneity among women ≥55 years (p=0.004). We jointly considered prevalence of high BMI and estimates of association between BMI and mammographic density by calculating PARs. For age &lt;55, after accounting for HT use, 26.7% (95% CI 26.3-27.2) of high mammographic density was explained by BMI ≤25. PARs were similar for NHW, Asian, and AIAN women, but lower for other groups, especially NHPI women (PAR%=9.8, 95% CI=6.4-13.3). For women age ≥55, 22.2% (95% CI 21.6-22.9) of high mammographic density was explained by BMI ≤25. PARs were similar for NHW, Hispanic, AIAN and NHPI women, and highest in NHB women (PAR%=42.2, 95% CI=35.9-48.5).

Discussion: We observed the strongest evidence of racial/ethnic differences in BMI when comparing the two groups most commonly studied together: Asians and NHPIs. While we present only limited evidence to suggest that BMI is differentially associated with breast density by race/ethnicity, differences in the prevalence of high BMI were substantial. Overall, our findings suggest that risk factor prevalence should not be overlooked when evaluating potential contributors to cancer disparities.

Citation Format: Mollie E. Barnard, Tarun Martheswaran, Karen Curtin, Jennifer A. Doherty. Body mass index and mammographic density by race and ethnicity [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 32.

Abstract 795: County-level radon and smoking exposure and lung cancer risk by histotype, sex, and race/ethnicity

Background: Radon and smoking synergistically increase risk of lung cancer, particularly for small cell and squamous cell carcinoma; however, associations by sex and race/ethnicity have not been reported.

Methods: We used data from the Behavioral Risk Factor Surveillance System (BRFSS), Environmental Protection Agency (EPA), and SEER21, excluding Alaska, to investigate the associations between county-level radon and smoking prevalence with lung cancer incidence by histotype, sex, and race/ethnicity (2006-2016). We only examined Non-Hispanic (NH) White and NH Black race/ethnicities due to the small proportion of cases from other groups. We used tertiles of sex-specific smoking prevalence estimates (1996-2000) from the BRFSS and EPA-defined radon zones of low, moderate, and high, to categorize 729 counties by both radon levels and smoking prevalence by sex. We fit generalized linear models using modified Poisson regression with Huber-White robust standard errors to compute rate ratios (RRs) and 95% confidence intervals (CIs) associating radon exposure, stratified by smoking tertile with histotype-specific lung cancer incidence.

Results: The smoking prevalence captured by each tertile was considerably lower for women (Low=9.0-22.4%, Moderate&gt;22.4-25.3, High&gt;25.3-36.6) than men (Low=14.4-27.3, Moderate&gt;27.3-31.6, High&gt;31.6-40.3). Among women, we observed the most pronounced associations between high radon and lung cancer risk compared to low radon within the highest female smoking tertile. These associations were evident among NH Black women, particularly for small cell carcinoma (RR=1.34, 95% CI: 1.05-1.71) and squamous cell carcinoma (RR=1.41, CI: 1.14-1.74), but were smaller and non-significant among NH White women. For men, the associations with radon were observed even in counties with low male smoking prevalence. For example, in counties in the lowest tertile of male smokers, associations of high radon with squamous cell and small cell lung cancer were observed among NH Black men (RR=1.27, 95% CI: 1.11-1.44, and RR=1.37, 95% CI:1.15-1.63, respectively) and NH White men (RR=1.18, 95% CI: 1.11-1.26, and RR=1.20, 95% CI: 1.11-1.29, respectively). When we considered that the percent of current smokers in the lowest smoking tertile for men overlaps the highest tertile for women, we observed radon-associated small cell and squamous cell lung cancer risk for NH Black men and women at comparable absolute smoking prevalence, and a similar but attenuated pattern in NH White men and women.

Discussion: While our analysis is limited by the ecological nature of the radon and smoking data, this research suggests that previously reported associations between radon and smoking exposure and histotype-specific lung cancer risk may differ by race and sex. Further research is needed to understand the impact of combined radon and smoking exposure on lung cancer risk in other racial and ethnic groups.

Citation Format: Rachel McCarty, Lindsay Collin, Laurie Grieshober, Judy Ou, Carol Sweeney, Mollie E. Barnard, Jennifer A. Doherty. County-level radon and smoking exposure and lung cancer risk by histotype, sex, and race/ethnicity [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 795.

Abstract A19: Aspirin use and ovarian cancer risk by lymphocyte infiltration

Introduction: There is growing evidence to support a modest inverse association between daily aspirin use and ovarian cancer risk. We previously hypothesized that this association may differ by immune cell infiltration. In our prior study evaluating heterogeneity by tumor-associated macrophage (TAM) infiltration, aspirin use was associated with lower risk of ovarian cancer with high protumorigenic M2-type TAM infiltration, but not low M2-type TAM infiltration. The goal of the present study was to evaluate the hypothesis that the association between aspirin use and ovarian cancer risk also differs by infiltration with tumor-infiltrating lymphocytes (TILs).

Methods: We included cases and matched controls from the Nurses’ Health Study (NHS), NHSII, and New England Case Control Study. Study participants self-reported aspirin use including regular use (≥1 x per week), duration of use, and number of tablets. A gynecologic pathologist (JLH), who was blinded to exposure status, reviewed hematoxylin and eosin stained tumor slides to quantify TILs for all cases (n=547). We used polytomous logistic regression, adjusted for ovarian cancer risk factors, to estimate odds ratios (OR) for aspirin use and ovarian cancer risk by TIL infiltration.

Results: Overall, recent aspirin use was associated with lower risk of ovarian cancer compared with no regular aspirin use (OR=0.65, 95%CI=0.47-0.89). Recent aspirin use was associated with a lower risk of ovarian cancer exhibiting TIL infiltration (OR=0.38, 95%CI=0.26-0.56) but not with TIL-negative cancers (OR=1.00, 95%CI=0.71-1.41; p-heterogeneity &lt;0.001). We observed similar results for aspirin duration and tablets. For duration, comparing ≥10 years of aspirin use to &lt;1 year we observed a significantly lower risk of ovarian cancer with TILs (OR=0.47, 95%CI=0.41-0.71; p-trend=0.004), but a nonsignificant reduction for ovarian cancer without TILs (OR=0.86, 95%CI=0.59-1.26; p-trend=0.72; p-heterogeneity=0.03). Comparing ≥6 tablets to &lt;1 tablet per week, there was evidence of a lower risk of ovarian cancer with TILs (OR=0.47, 95%CI=0.30-0.75; p-trend=0.001) but not without TILs (OR=1.02, 95%CI=0.70-1.48; p-trend=0.84; p-heterogeneity=0.003).

Conclusions: Our results suggest that prediagnosis aspirin use may be an important modulator of immune cell infiltration in ovarian tumors, supporting an immunogenic mechanism for aspirin in ovarian carcinogenesis. Further work is under way to evaluate nonaspirin nonsteroidal anti-inflammatory drugs, and to consider which subsets of TAMs and TILs may be driving heterogeneity in the associations between anti-inflammatory drugs and ovarian cancer risk.

Citation Format: Mollie E. Barnard, Britton Trabert, Jonathan L. Hecht, Ellen L. Goode, Naoko Sasamoto, Kathryn L. Terry, Shelley S. Tworoger. Aspirin use and ovarian cancer risk by lymphocyte infiltration [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A19.

Abstract 3485: Body mass index and mammographic density among Native Hawaiians and Pacific Islanders

Background: Mammographic density is an important breast cancer risk factor, yet data on mammographic density is limited for some racial/ethnic groups, including Native Hawaiians and Pacific Islanders (NHPI). Obesity is highly prevalent in the NHPI population and prior work, primarily in non-Hispanic White (NHW) women, has reported that high body mass index (BMI) is inversely associated with mammographic density but positively associated with risk of breast cancer. We used data from the Utah Population Database (UPDB) to estimate the association between BMI and mammographic density in Utah's NHPI population and evaluate if the association differs for NHPI women compared to NHW women.

Methods: We included women ages 18-79 years with at least one mammogram from 2005-2012 and no history of breast cancer. Data on BMI and race/ethnicity were collected from the UPDB, and mammographic density was evaluated using Breast Imaging Reporting and Data System (BIRADS) scores. We estimated the association between BMI and BIRADS using multinomial logistic regression adjusted for age and stratified at age 55 (a proxy for menopausal status). Heterogeneity by race/ethnicity was evaluated using likelihood ratio tests.

Results: Our analyses included data from 102 Native Hawaiian, 112 Samoan, 344 other Pacific Islander, and 143,259 NHW women. High mammographic density (BIRADS=4) was less common among Samoan women (2.7%) and other Pacific Islanders (4.7%) compared to NHW women (5.8%), but more common among Native Hawaiians (11.8%). Age-standardized BMI was highest in Samoan women (mean=32.3, SD=6.3) followed by other Pacific Islander women (mean=31.2, SD=7.1) then Native Hawaiian women (mean=27.8, SD=6.4), and lowest among NHW women (mean=26.1, SD=5.4). Among women younger than age 55, a one-unit increase in BMI was associated with 0.76 (95% CI=0.69-0.84) times lower odds of high (BIRADS=4) versus low (BIRADS=1) breast density in NHPI women. The comparable odds ratio (OR) in NHW women was 0.66 (95% CI=0.65-0.66; p-heterogeneity=6.9 × 10^-10). For women age 55 and older, the association between BMI and mammographic density was stronger among NHPI women, OR=0.62 (95%CI=0.45-0.84), compared to NHW women, OR=0.70 (95%CI=0.69-0.72; p-heterogeneity=0.018).

Discussion: Mammographic density differs among racial/ethnic subgroups of the NHPI population with Native Hawaiians having the highest mammographic density. Given the high prevalence of obesity in the NHPI population and evidence that the association between BMI and mammographic density may differ by race/ethnicity, more research is needed to understand how BMI and mammographic density influence risk of breast cancer in understudied racial/ethnic minorities, such as NHPIs.

Citation Format: Mollie E. Barnard, Tarun Martheswaran, Jennifer A. Doherty, Karen Curtin. Body mass index and mammographic density among Native Hawaiians and Pacific Islanders [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3485.

Identification of novel epithelial ovarian cancer loci in women of African ancestry

Women of African ancestry have lower incidence of epithelial ovarian cancer (EOC) yet worse survival compared to women of European ancestry. We conducted a genome-wide association study in African ancestry women with 755 EOC cases, including 537 high-grade serous ovarian carcinomas (HGSOC) and 1,235 controls. We identified four novel loci with suggestive evidence of association with EOC (p < 1 × 10-6 ), including rs4525119 (intronic to AKR1C3), rs7643459 (intronic to LOC101927394), rs4286604 (12 kb 3' of UGT2A2) and rs142091544 (5 kb 5' of WWC1). For HGSOC, we identified six loci with suggestive evidence of association including rs37792 (132 kb 5' of follistatin [FST]), rs57403204 (81 kb 3' of MAGEC1), rs79079890 (LOC105376360 intronic), rs66459581 (5 kb 5' of PRPSAP1), rs116046250 (GABRG3 intronic) and rs192876988 (32 kb 3' of GK2). Among the identified variants, two are near genes known to regulate hormones and diseases of the ovary (AKR1C3 and FST), and two are linked to cancer (AKR1C3 and MAGEC1). In follow-up studies of the 10 identified variants, the GK2 region SNP, rs192876988, showed an inverse association with EOC in European ancestry women (p = 0.002), increased risk of ER positive breast cancer in African ancestry women (p = 0.027) and decreased expression of GK2 in HGSOC tissue from African ancestry women (p = 0.004). A European ancestry-derived polygenic risk score showed positive associations with EOC and HGSOC in women of African ancestry suggesting shared genetic architecture. Our investigation presents evidence of variants for EOC shared among European and African ancestry women and identifies novel EOC risk loci in women of African ancestry.

Association of Analgesic Use With Risk of Ovarian Cancer in the Nurses' Health Studies

Importance

Ovarian cancer is a highly fatal malignant neoplasm with few modifiable risk factors. Case-control studies have reported a modest reduced risk of ovarian cancer among women who frequently use aspirin or regularly use low-dose aspirin.

Objective

To evaluate whether regular aspirin or nonaspirin nonsteroidal anti-inflammatory drug (NSAID) use and patterns of use are associated with lower ovarian cancer risk.

Design, Setting, and Participants

This cohort study analyzed NSAID use and ovarian cancer diagnosis data from 2 prospective cohorts, 93 664 women in the Nurses' Health Study (NHS), who were followed up from 1980 to 2014, and 111 834 in the Nurses' Health Study II (NHSII), who were followed up from 1989 to 2015. Follow-up was completed on June 30, 2014, for the NHS and June 30, 2015, for NHSII. Data were analyzed from June 13, 2016, to September 18, 2017.

Exposures

For each analgesic type (aspirin, low-dose aspirin, nonaspirin NSAIDs, and acetaminophen), timing, duration, frequency, and number of tablets used were evaluated; exposure information was updated every 2 to 4 years.

Main Outcomes and Measures

Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for associations of aspirin, nonaspirin NSAIDs, and acetaminophen with risk of epithelial ovarian cancer. All statistical tests were 2-sided, with a significance level of .05.

Results

In the NHS, the mean (SD) age at baseline (1980) was 45.9 (7.2) years, and 93% of participants identified as non-Hispanic white. In the NHSII, the mean age at baseline (1989) was 34.2 (4.7) years, and 92% identified as non-Hispanic white. Among the 205 498 women in both cohorts, there were 1054 cases of incident epithelial ovarian cancer. Significant associations between aspirin and ovarian cancer risk were not observed when current vs nonuse of any aspirin was evaluated regardless of dose (HR, 0.99; 95% CI, 0.83-1.19). However, when low-dose (≤100-mg) and standard-dose (325-mg) aspirin were evaluated separately, an inverse association for low-dose aspirin (HR, 0.77; 95% CI, 0.61-0.96), but no association for standard-dose aspirin (HR, 1.17; 95% CI, 0.92-1.49) was observed. Current use of nonaspirin NSAIDs was positively associated with risk of ovarian cancer compared with nonuse (HR, 1.19; 95% CI, 1.00-1.41), and significant positive trends for duration of use (P = .02 for trend) and cumulative average tablets per week (P = .03 for trend) were observed. There were no clear associations for the use of acetaminophen.

Conclusions and Relevance

These results appear to be consistent with case-control studies that show a reduced risk of ovarian cancer among regular users of low-dose aspirin. An increased risk of ovarian cancer with long-term high-quantity use of other analgesics, particularly nonaspirin NSAIDs, was observed, although this finding requires confirmation.

Urinary PGE-M Levels and Risk of Ovarian Cancer

BACKGROUND

Regular aspirin use may lower ovarian cancer risk by blocking the cyclooxygenase enzymes, resulting in lower expression of prostaglandins, including prostaglandin E2 (PGE2). We evaluated whether higher prediagnosis PGE-M (a urinary biomarker of PGE2) was associated with increased ovarian cancer risk in three prospective cohorts.

METHODS

We conducted a case-control study nested in the Nurses' Health Study (NHS), NHSII, and Shanghai Women's Health Study. Our analyses included 304 cases of epithelial ovarian cancer diagnosed from 1996 to 2015 and 600 matched controls. We measured urinary PGE-M using LC/MS with normalization to creatinine. Measures from each study were recalibrated to a common standard. We estimated ORs and 95% confidence intervals (CI) using conditional logistic regression, with PGE-M levels modeled in quartiles. Multivariable models were adjusted for ovarian cancer risk factors.

RESULTS

There was no evidence of an association between urinary PGE-M levels and ovarian cancer risk for women with PGE-M levels in the top versus bottom quartile (OR = 0.80; 95% CI, 0.51-1.27; P _trend = 0.37). We did not observe heterogeneity by histotype (P = 0.53), and there was no evidence of effect modification by body mass index (P _interaction = 0.82), aspirin use (P _interaction = 0.59), or smoking (P _interaction = 0.14).

CONCLUSIONS

Prediagnosis urinary PGE-M levels were not significantly associated with ovarian cancer risk. Larger sample sizes are needed to consider a more modest association and to evaluate associations for specific tumor subtypes.

IMPACT

Systemic prostaglandin levels do not appear strongly associated with ovarian cancer risk. Future research into aspirin use and ovarian cancer risk should consider local prostaglandins and prostaglandin-independent mechanisms.

Abstract 4174: Familiality of ovarian cancer histotypes in the Utah Population Database

Introduction: Ovarian cancer is a heterogeneous disease; each histotype has distinct molecular origins, risk factors and outcomes. While it is well established that ovarian cancer has a familial risk component, the familiality of ovarian cancer histotypes has not been well described. The Utah Population Database (UPDB) captures over 10 million individuals, including more than 5 million with a minimum of three generations of genealogy data. By linking records from the UPDB to the Utah Cancer Registry (UCR) and other statewide data sources, we sought to describe the familiality of ovarian cancer histotypes.

Methods: Our study includes all ovarian cancer cases in the UPDB and leverages clinical data reported to UCR for the case histotypes. Cases were matched to controls on age, birth cohort and at least three generations of UPDB data versus not. We quantified familiality by comparing the odds of ovarian cancer occurrence among family members of cases to the odds of ovarian cancer among family members of matched controls. We calculated odds ratios for first-degree relatives, second-degree relatives, and first cousins.

Results: As of September 2018, the UPDB included 3,989 ovarian cancer cases. We observed an increased risk of epithelial ovarian cancer among first-degree relatives (OR=1.62, 95%CI=1.36-1.93), second-degree relatives (OR=1.53, 95%CI=1.34-1.74), and first cousins (OR=1.38, 95%CI=1.26-1.53) of ovarian cancer cases. When we analyzed epithelial ovarian cancers by histotype, familiality was most evident for high-grade serous, mucinous, and unclassified cancers. For example, we observed a 1.62-fold increased odds (95%CI=1.14-2.29) of high-grade serous ovarian cancer among the first-degree relatives of high-grade serous cases, and a 5.59-fold increased odds (95%CI=2.09-14.92) of mucinous ovarian cancer among first-degree relatives of mucinous ovarian cancer cases. Familiality patterns were less clear among endometrioid and clear cell cases.

Conclusions: The UPDB has the potential to contribute greatly to family-based studies of the genetics of ovarian cancer histotypes. Despite the possible variations in quality of histotype data across generations, preliminary results suggest some histotypes may be particularly familial and good candidates for gene mapping studies. Work is ongoing to refine the histotype assignments for cases by performing pathology review using the 2014 World Health Organization guidelines. Analyses are also in progress to stratify analyses by BRCA mutation status, and to consider the potential for shared familiality across ovarian cancer histotypes and with cancers at other sites.

Citation Format: Mollie E. Barnard, Nicola J. Camp, Jennifer A. Doherty. Familiality of ovarian cancer histotypes in the Utah Population Database [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4174.

Anti-Inflammatory Drug Use and Ovarian Cancer Risk by COX1/COX2 Expression and Infiltration of Tumor-Associated Macrophages

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use may affect ovarian cancer risk via prostaglandin synthesis and tumor-associated macrophage (TAM) infiltration. We evaluated if associations between aspirin or non-aspirin NSAID use and ovarian cancer risk differed by tumor expression of prostaglandin-related (COX1, COX2) and TAM-related (CD68, CD163) markers.

METHODS

We evaluated cases and matched controls from the Nurses' Health Study (NHS), NHSII, and New England Case-Control Study (NECC). Cases with IHC data on COX1 and COX2 (n = 532) or CD68 and CD163 (n = 530) were included. We used polytomous logistic regression, adjusted for ovarian cancer risk factors, to estimate OR for NSAID use and ovarian cancer risk by marker level.

RESULTS

Recent aspirin use had a nonsignificant inverse association and recent non-aspirin NSAID use had no association with ovarian cancer risk. NSAID use was not differentially associated with ovarian cancer by COX1 or COX2 expression. However, recent aspirin use was associated with lower ovarian cancer risk for high [OR 0.54; 95% confidence interval (CI), 0.37-0.78], but not low (OR 1.50; 95% CI, 0.97-2.31), CD163 density (P _{heterogeneity} < 0.001). Similar results were observed for aspirin duration and tablets and for recent non-aspirin NSAID use. Results were not clearly different by macrophage density defined by the less specific macrophage marker, CD68.

CONCLUSIONS

NSAID use was inversely associated with risk of ovarian cancer with high density CD163, a marker for M2-type, immunosuppressive macrophages. However, the relationship did not differ by prostaglandin synthesis markers.

IMPACT

Future research should explore prostaglandin-independent mechanisms for the association between NSAID use and ovarian cancer risk, including immune mechanisms.

Abstract B08: Urinary PGE-M levels and risk of ovarian cancer

Introduction: Prostaglandin E2 (PGE2) is thought to influence ovarian carcinogenesis by increasing cell proliferation, tumor cell invasiveness, and angiogenesis. PGE-M is the major metabolite of PGE2 and a marker of systemic PGE2 production. Prior research has reported positive associations between urinary PGE-M and risk of colorectal, gastric, lung, pancreatic, and breast cancer; however, this is the first study to evaluate the association between urinary PGE-M and risk of ovarian cancer.

Methods: We conducted a prospective case-control study nested in the Nurses’ Health Study (NHS) and NHSII cohorts. We included 194 cases of invasive epithelial ovarian cancer and 387 matched controls. All cases were diagnosed between the time of urine specimen collection (1996-97 NHSII; 2000-2002 NHS) and the end of follow-up (2015). Controls were selected using incidence density sampling and matched to cases on year of birth, menopausal status at collection and diagnosis, date and time of day of collection, hormone therapy use at collection, and fasting status. We measured PGE-M levels using LC/MS methods, and used the PGE-M distribution among controls to identify tertile cutpoints. We estimated the association between prediagnosis urinary PGE-M (in tertiles) and risk of ovarian cancer using conditional logistic regression.

Results: We observed a suggestively lower risk of ovarian cancer for those with the highest PGE-M levels in NHS (OR=0.66; 95%CI=0.36-1.21; p-trend=0.15; n=123 cases), and no association in NHSII (OR=1.15; 95%CI=0.50-2.67; p-trend=0.75; n=71 cases). When results from the two cohorts were pooled, we observed nonsignificant, lower odds of ovarian cancer among those in the highest tertile of PGE-M compared to the lowest tertile (OR=0.80; 95%CI=0.50-1.27; p-trend=0.34), particularly after restricting our analysis to study participants who provided first morning urine samples (OR=0.68; 95%CI=0.40-1.14; p-trend=0.13). However, when we examined quartiles, no clear association was observed, although power was limited.

Conclusions: Overall, our results suggest that higher prediagnosis PGE-M levels are not associated with an increased risk of ovarian cancer. Further analyses are under way to evaluate the potential for effect modification by menopausal status, BMI, and NSAID use.

Citation Format: Mollie E. Barnard, A. Heather Eliassen, Bernard A. Rosner, Kathryn L. Terry, Ginger L. Milne, Shelley S. Tworoger. Urinary PGE-M levels and risk of ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B08.

Abstract 4217: Prognostic gene expression signatures of immune responses in the colon cancer microenvironment

Colorectal cancer remains the 2nd leading cause of cancer deaths in the United States. This suggests that traditional prognostic factors are not optimally refined for predicting survival outcomes and guiding therapeutic decisions for some patients. Mounting evidence supports that quantifying the strength and diversity of host immune responses in the tumor microenvironment may improve prognostication and clinical decision-making; however, standard pathological assessment of T cell infiltration is time-consuming and difficult to standardize for clinical utility. The goal of this study was to develop a molecular classifier associated with CRC prognosis based on the expression of 770 immune-related genes measured on the Nanostring (NS) nCounter PanCancer Immune Profiling Panel. This panel includes markers of immune cell types, common cancer antigens, and diverse categories of immune responses (e.g. T cell function, cytokines). We also aimed to assess the validity of combining gene expression data derived from different tissue types (FFPE, fresh frozen) and mRNA profiling platforms (NS, Rosetta/Merck human RSTA Custom Affymetrix 2.0 microarray). FFPE (N=24) and fresh frozen tumor tissues (N=28) from 50 primary stage II colon cancers from the Moffitt Cancer Center Total Cancer Care cohort were profiled using the NS platform, and microarray data were generated on frozen tissues from all patients. Geometric mean-normalized NS data of FFPE and frozen tumor tissues were merged by the ComBat algorithm that adjusted for different RNA source types. 634 (87%) genes in the NS dataset had expression values that positively correlated with those of the microarray data. A 2-way hierarchical cluster analysis of these genes in NS data revealed two clusters of patients with non-overlapping overall survival (OS) curves, but no statistically significant difference due mainly to a lack of events (Log-rank P=0.12; 5-year OS probability=91.3% vs 74.1% for cluster 1 (N=23) and cluster 2 (N=27)). To examine cross-platform predictability of the 2 clusters, a 5-gene classifier was trained on NS data using penalized logistic regression. Applying this classifier to microarray data on the same patient set (N=49) significantly discriminated the clusters (AUC=0.8, P&lt;0.01). Functional annotation of the 5 genes (CD27, CD37, ITGAL, KLRG1 and LAG3) revealed enrichment for T cell receptor signaling, hematopoietic cell lineage, and natural killer cell mediated cytotoxicity (FDR P&lt;0.001). This pilot study provides early evidence that an immune gene expression panel may capture the prognostic value of intratumoral host immune responses. It also supports the feasibility of combining different RNA sources and expression platforms. Expanded future studies that pool across sample types and publicly-available expression datasets are needed to validate the 9-gene classifier from this study and examine its broader prognostic impact.

Citation Format: Youngchul Kim, Hannah J. Hoehn, Yunyun Chen, Mollie E. Barnard, Amanda Bloomer, Sean Yoder, Domenico Coppola, Stephanie L. Schmit. Prognostic gene expression signatures of immune responses in the colon cancer microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4217.

Nurses' Health Study Contributions on the Epidemiology of Less Common Cancers: Endometrial, Ovarian, Pancreatic, and Hematologic

OBJECTIVES

To review the contributions of the Nurses' Health Study (NHS) to epidemiologic knowledge of endometrial, ovarian, pancreatic, and hematologic cancers.

METHODS

We reviewed selected NHS publications from 1976 to 2016, including publications from consortia and other pooled studies.

RESULTS

NHS studies on less common cancers have identified novel risk factors, such as a reduced risk of endometrial cancer in women of advanced age at last birth, and have clarified or prospectively confirmed previously reported associations, including an inverse association between tubal ligation and ovarian cancer. Through biomarker research, the NHS has furthered understanding of the pathogenesis of rare cancers, such as the role of altered metabolism in pancreatic cancer risk and survival. NHS investigations have also demonstrated the importance of the timing of exposure, such as the finding of a positive association of early life body fatness, but not of usual adult body mass index, with non-Hodgkin lymphoma risk.

CONCLUSIONS

Evidence from the NHS has informed prevention strategies and contributed to improved survival from less common but often lethal malignancies, including endometrial, ovarian, pancreatic, and hematologic cancers.

Physiological consequences of abnormal connectivity in a developmental epilepsy

OBJECTIVE

Many forms of epilepsy are associated with aberrant neuronal connections, but the relationship between such pathological connectivity and the underlying physiological predisposition to seizures is unclear. We sought to characterize the cortical excitability profile of a developmental form of epilepsy known to have structural and functional connectivity abnormalities.

METHODS

We employed transcranial magnetic stimulation (TMS) with simultaneous electroencephalographic (EEG) recording in 8 patients with epilepsy from periventricular nodular heterotopia and matched healthy controls. We used connectivity imaging findings to guide TMS targeting and compared the evoked responses to single-pulse stimulation from different cortical regions.

RESULTS

Heterotopia patients with active epilepsy demonstrated a relatively augmented late cortical response that was greater than that of matched controls. This abnormality was specific to cortical regions with connectivity to subcortical heterotopic gray matter. Topographic mapping of the late response differences showed distributed cortical networks that were not limited to the stimulation site, and source analysis in 1 subject revealed that the generator of abnormal TMS-evoked activity overlapped with the spike and seizure onset zone.

INTERPRETATION

Our findings indicate that patients with epilepsy from gray matter heterotopia have altered cortical physiology consistent with hyperexcitability, and that this abnormality is specifically linked to the presence of aberrant connectivity. These results support the idea that TMS-EEG could be a useful biomarker in epilepsy in gray matter heterotopia, expand our understanding of circuit mechanisms of epileptogenesis, and have potential implications for therapeutic neuromodulation in similar epileptic conditions associated with deep lesions.

Integration of gray matter nodules into functional cortical circuits in periventricular heterotopia

Alterations in neuronal circuitry are recognized as an important substrate of many neurological disorders, including epilepsy. Patients with the developmental brain malformation of periventricular nodular heterotopia (PNH) often have both seizures and dyslexia, and there is evidence to suggest that aberrant neuronal connectivity underlies both of these clinical features. We used task-based functional MRI (fMRI) to determine whether heterotopic nodules of gray matter in this condition are integrated into functional cortical circuits. Blood oxygenation level-dependent (BOLD) fMRI was acquired in eight participants with PNH during the performance of reading-related tasks. Evidence of neural activation within heterotopic gray matter was identified, and regions of cortical coactivation were then mapped systematically. Findings were correlated with resting-state functional connectivity results and with performance on the fMRI reading-related tasks. Six participants (75%) demonstrated activation within at least one region of gray matter heterotopia. Cortical areas directly overlying the heterotopia were usually coactivated (60%), as were areas known to have functional connectivity to the heterotopia in the task-free resting state (73%). Six of seven (86%) primary task contrasts resulted in heterotopia activation in at least one participant. Activation was most commonly seen during rapid naming of visual stimuli, a characteristic impairment in this patient population. Our findings represent a systematic demonstration that heterotopic gray matter can be metabolically coactivated in a neuronal migration disorder associated with epilepsy and dyslexia. Gray matter nodules were most commonly coactivated with the anatomically overlying cortex and other regions with resting-state connectivity to heterotopia. These results have broader implications for understanding the network pathogenesis of both seizures and reading disabilities.

The focusing of surface-acoustic-waves launched from a slanted chirped transducer. I. Isotropic substrate

The focusing behavior of surface acoustic waves launched from a slanted chirped transducer (SCT) is explored using both a continuum model and a discrete model for sources associated with a linear FM chirp transducer on a substrate with isotropic properties. The continuum model leads to the prediction of an understanding of effects that would arise in the radiation field of an SCT on an isotropic substrate. It is based on a representation of the transducer as a continuum of sources, with the radiation field determined by applying the stationary phase method, and is presented for infinitesimally short fingers. It is compared with a more direct and exact but less revealing method of determining the field based on a discrete array of sources. The effects of increasing finger lengths are considered. The results are related to the focusing of radiation by a lens.