Understanding mechanisms of racial disparities in breast cancer: an assessment of screening and regular care in the Carolina Breast Cancer Study

PURPOSE

Screening history influences stage at detection, but regular preventive care may also influence breast tumor diagnostic characteristics. Few studies have evaluated healthcare utilization (both screening and primary care) in racially diverse screening-eligible populations.

METHODS

This analysis included 2,058 women age 45-74 (49% Black) from the Carolina Breast Cancer Study, a population-based cohort of women diagnosed with invasive breast cancer between 2008 and 2013. Screening history (threshold 0.5 mammograms per year) and pre-diagnostic healthcare utilization (i.e. regular care, based on responses to "During the past ten years, who did you usually see when you were sick or needed advice about your health?") were assessed as binary exposures. The relationship between healthcare utilization and tumor characteristics were evaluated overall and race-stratified.

RESULTS

Among those lacking screening, Black participants had larger tumors (5 + cm) (frequency 19.6% vs 11.5%, relative frequency difference (RFD) = 8.1%, 95% CI 2.8-13.5), but race differences were attenuated among screening-adherent participants (10.2% vs 7.0%, RFD = 3.2%, 0.2-6.2). Similar trends were observed for tumor stage and mode of detection (mammogram vs lump). Among all participants, those lacking both screening and regular care had larger tumors (21% vs 8%, RR = 2.51, 1.76-3.56) and advanced (3B +) stage (19% vs 6%, RR = 3.15, 2.15-4.63) compared to the referent category (screening-adherent and regular care). Under-use of regular care and screening was more prevalent in socioeconomically disadvantaged areas of North Carolina.

CONCLUSIONS

Access to regular care is an important safeguard for earlier detection. Our data suggest that health equity interventions should prioritize both primary care and screening.

Individual and Neighborhood-level Socioeconomic Status and Somatic Mutations Associated With Increased Risk of Cardiovascular Disease and Mortality: A Cross-Sectional Analysis in the Women's Health Initiative

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP), the expansion of leukemogenic mutations in white blood cells, has been associated with increased risk of atherosclerotic cardiovascular diseases, cancer, and mortality.

OBJECTIVE

We examined the relationship between individual- and neighborhood-level socioeconomic status (SES) and CHIP and evaluated effect modification by interpersonal and intrapersonal resources.

METHODS

The study population included 10,799 postmenopausal women from the Women's Health Initiative without hematologic malignancy or antineoplastic medication use. Individual- and neighborhood (Census tract)-level SES were assessed across several domains including education, income, and occupation, and a neighborhood-level SES summary z-score, which captures multiple dimensions of SES, was generated. Interpersonal and intrapersonal resources were self-reports. CHIP was ascertained based on a prespecified list of leukemogenic driver mutations. Weighted logistic regression models adjusted for covariates were used to estimate risk of CHIP as an odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

The interval-scale neighborhood-level SES summary z-score was associated with a 3% increased risk of CHIP: OR (95% CI) = 1.03 (1.00-1.05), p = .038. Optimism significantly modified that estimate, such that among women with low/medium and high levels of optimism, the corresponding ORs (95% CIs) were 1.03 (1.02-1.04) and 0.95 (0.94-0.96), pInteraction < .001.

CONCLUSIONS

Our findings suggest that reduced risk of somatic mutation may represent a biological pathway by which optimism protects contextually advantaged but at-risk women against age-related chronic disease and highlight potential benefits of long-term, positive psychological interventions.

Linking African ancestral substructure to prostate cancer health disparities

Prostate cancer (PCa) is a significant health burden in Sub-Saharan Africa, with mortality rates loosely linked to African ancestry. Yet studies aimed at identifying contributing risk factors are lacking within the continent and as such exclude for significant ancestral diversity. Here, we investigate a series of epidemiological demographic and lifestyle risk factors for 1387 men recruited as part of the multi-ethnic Southern African Prostate Cancer Study (SAPCS). We found poverty to be a decisive factor for disease grade and age at diagnosis, with other notably significant PCa associated risk factors including sexually transmitted diseases, erectile dysfunction, gynaecomastia, and vertex or complete pattern balding. Aligned with African American data, Black ethnicity showed significant risk for PCa diagnosis (OR = 1.44, 95% CI 1.05-2.00), and aggressive disease presentation (ISUP ≥ 4: OR = 2.25, 95% CI   1.49-3.40). New to this study, we demonstrate African ancestral population substructure associated PCa disparity, observing increased risk for advanced disease for the southern African Tsonga people (ISUP ≥ 4: OR = 3.43, 95% CI   1.62-7.27). Conversely, South African Coloured were less likely to be diagnosed with aggressive disease overall (ISUP ≥ 3: OR = 0.38, 95% 0.17-0.85). Understanding the basis for PCa health disparities calls for African inclusion, however, lack of available data has limited the power to begin discussions. Here, focusing on arguably the largest study of its kind for the African continent, we draw attention to the contribution of within African ancestral diversity as a contributing factor to PCa health disparities within the genetically diverse region of southern Africa.

Abstract 3508: Association between clonal hematopoiesis and risk of prostate cancer in a large sample of African ancestry men

Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with inflammation, which is a risk factor for cancer, including prostate cancer. We previously reported weak evidence of an association between CHIP and prostate cancer risk in men of European ancestry. However, little is known for African ancestry populations. We investigated the association of age-related CHIP with overall and aggressive prostate cancer risk in a large whole-exome sequencing study of 12,049 African ancestry men, including 7,176 prostate cancer cases (of which 3,283 had aggressive disease and 1,074 had metastatic disease) and 4,873 controls. Somatic variant calling was carried out using GATK Mutect2, and only variants with minor allele frequencies (MAF) &lt;0.1% and a variant allelic fraction (VAF) &gt;5% were included. Variants with a MAF ≥0.1% in gnomAD were excluded. CHIP variants were identified from a list of pre-specified mutations in 74 genes. Associations were tested using regression models adjusting for age, sub-study, and top 10 principal components, with statistical significance tested by the likelihood ratio test and applying a Bonferroni correction to account for multiple testing. In total, 998 variants in 57 CHIP genes were identified. Consistent with previous results, we observed a strong association between CHIP and age at blood draw. CHIP genes in aggregate were not statistically significantly associated with risks of total (OR=1.12, 95% CI=0.97-1.28), aggressive (OR=1.14, 95% CI=0.92-1.43) or metastatic (OR=1.17, 95% CI=0.91-1.49) prostate cancer. We observed that carriers of variants in DNMT3A, which is the gene that harbors the most CHIP driver mutations, had a nominally elevated risk of prostate cancer compared to non-carriers (OR=1.35, 95% CI=1.08-1.68, p=0.007). Additionally, carriers of variants in EZH2, which is implicated in cancer progression, showed a suggestive association with aggressive prostate cancer (OR=7.33, 95% CI=1.01-53.21, p=0.029). After adjusting for age at blood draw, CHIP genes in aggregate were not associated with age at prostate cancer diagnosis. However, we found that EZH2 variants carriers were diagnosed 12.9 years earlier on average than non-carriers (95% CI=6.1-19.7, adjusted p=0.01). A prostate cancer polygenic risk score (PRS) constructed using 269 risk variants was not associated with CHIP carrier status in aggregate (OR=0.99, 95% CI=0.92-1.06, p=0.70) or with any individual gene (all adjusted p&gt;0.05). In summary, overall CHIP is not likely to be a risk factor of prostate cancer or aggressive disease in men of African ancestry. However, our results do confirm the association of CHIP in DNMT3A with prostate cancer risk as reported in previous studies in men of European ancestry. Future work will be needed to evaluate the biological causality of DNMT3A- and EZH2- related CHIP on prostate cancer.

Citation Format: Anqi Wang, Yili Xu, Xin Sheng, Raymond Hughley, Ben Adusei, Mohamed Jalloh, Serigne Magueye Gueye, Andrew A Adjei, James Mensah, Pedro W. Fernandez, Akin Olupelumi Adebiyi, Oseremen Inokhoife Aisuodionoe-Shadrach, Lindsay Petersen, Maureen Joffe, Jeannette T. Bensen, James L. Mohler, Jack A. Taylor, Eboneé N. Butler, Sue A. Ingles, Benjamin A. Rybicki, Janet L. Stanford, Wei Zheng, Sonja I. Berndt, Chad D. Huff, Joseph Lachance, Luc Multigner, Caroline Andrews, Timothy R. Rebbeck, Laurent Brureau, Stephen J. Chanock, Adam de Smith, Fei Chen, Burcu F. Darst, David V. Conti, Christopher A. Haiman. Association between clonal hematopoiesis and risk of prostate cancer in a large sample of African ancestry men [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 3508.

Breast exam use during the protracted COVID-19 pandemic, by age, race, and geography

In this study we analyzed data collected from the onset of the COVID-19 pandemic through March 31, 2022 to identify temporal shifts in breast exam volume. Screening mammography volume stabilized toward the end of the study period, while diagnostic exam volume varied over time and by age. Older women experienced a decline in diagnostic exam volume between August 2020 and April 2021 that was not observed among women aged 50 years or less (50-69 years, monthly percentage change (MPC): -6.5; and 70+ years, MPC: -15.7). With respect to breast biopsy volume, women younger than 70 years of age had increased exam volume beginning in April 2020 and June 2020, whereas a corresponding increase among older women was delayed until April 2021(70+ years, MPC: 9.3). Findings from our study suggest a temporal shift in the use of breast exams that could result in differential detection of breast cancer by age.

Testosterone therapy and cancer risks among men in the SEER-Medicare linked database

BACKGROUND

We examined associations between two forms of testosterone therapy (TT) and risks of seven cancers among men.

METHODS

SEER-Medicare combines cancer registry data from the Surveillance, Epidemiology, and End Results programme with Medicare claims. Our population-based case-control study included incident cancer cases diagnosed between 1992-2015: prostate (n = 130,713), lung (n = 105,466), colorectal (n = 56,433), bladder (n = 38,873), non-Hodgkin lymphoma (n = 17,854), melanoma (n = 14,241), and oesophageal (n = 9116). We selected 100,000 controls from a 5% random sample of Medicare beneficiaries and used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

TT was associated with lower risk of distant-stage prostate cancer (injection/implantation OR = 0.72, 95% CI: 0.60-0.86; topical OR = 0.50, 95% CI: 0.24-1.03). We also observed inverse associations for distant-stage colorectal cancer (injection/implantation OR = 0.75, 95% CI: 0.62-0.90; topical OR = 0.11, 95% CI: 0.05-0.24). Risks of distant-stage colorectal and prostate cancers decreased with time after initiating TT by injection/implantation. By contrast, TT was positively associated with distant-stage melanoma (injection/implantation OR = 1.70, 95% CI: 1.37-2.11). TT was not associated with bladder cancer, oesophageal cancer, lung cancer or non-Hodgkin lymphoma.

CONCLUSION

TT was inversely associated with distant-stage prostate and colorectal cancers but was positively associated with distant-stage melanoma. These observations may suggest an aetiologic role for TT or the presence of residual confounding.

Redefining precision cancer prevention to promote health equity

Precision cancer prevention as it is currently envisioned is a targeted, molecular-based approach to intercept carcinogenesis before cancer develops or before it becomes untreatable. Unfortunately, due to systemic biases, current precision cancer prevention interventions might not be effective in all populations, especially in minoritized communities. In addition, not all cancer risk is attributable to genetic or even biological factors, but includes social determinants of health (SDH). Here, we propose a broader framework for precision cancer prevention, anchored in optimizing the benefits to harms for all people. We propose that precision cancer prevention considers not only what is being delivered, but also for whom, where, and how, with a goal of achieving cancer prevention health equity.

Oncologist-Reported Reasons for Not Ordering Multimarker Tumor Panels: Results From a Nationally Representative Survey

This study examines oncologist-reported reasons for not using multimarker tumor panel testing and the association between these reasons and oncologist-level, facility-level, and patient-mix characteristics.

METHODS

We used data collected from a nationally representative sample (N = 1,281) of medical oncologists participating in the National Cancer Institute's National Survey of Precision Medicine in Cancer Treatment.

RESULTS

In addition to testing not being seen as relevant (87%) and no evidence of test utility (77%), the most frequently reported reasons for not ordering a multimarker tumor panel test was difficulty in obtaining sufficient tissue (57%) and using individual gene tests (72%). These reasons were more likely to be reported by oncologists practicing in rural clinics and less likely to be reported by oncologists with an academic affiliation or with access to genetic services such as on-site genetic counselors and internal genetic testing policies.

CONCLUSION

Modifiable, organizational factors were associated with ordering multimarker tumor panels. Receipt of genomics training and organizational policies related to the use of genomics were associated with lower reporting of barriers to ordering multimarker tumor panels, pointing to potential targets for future studies aimed at increasing appropriate multimarker tumor panel testing in cancer treatment management.

Involving patients and their families in deciding to use next generation sequencing: Results from a nationally representative survey of U.S. oncologists

OBJECTIVE

Next generation sequencing (NGS) may aid in tumor classification and treatment. Barriers to shared decision-making may influence use of NGS. We examined, from oncologists' perspectives, whether barriers to involving patients/families in decision-making were associated with NGS use.

METHODS

Using data from the first national survey of medical oncologists' perspectives on precision medicine (N = 1281), we approached our analyses in two phases. Bivariate analyses initially evaluated associations between barriers to involving patients/families in deciding to use NGS and provider- and organizational-level characteristics. Modified Poisson regressions then examined associations between patient/family barriers and NGS use.

RESULTS

Approximately 59 % of oncologists reported at least one barrier to involving patients/families in decision-making regarding NGS use. Those reporting patient/family barriers tended to have fewer genomic resources at their practices, to be in rural or suburban areas, and to have a higher proportion of Medicaid patients. However, these barriers were not associated with NGS use.

CONCLUSIONS

Oncologists encounter barriers to involving patients/families in NGS testing decisions. Organizational barriers may also potentially play a role in testing decisions.

PRACTICE IMPLICATIONS

To foster patient-centered care, strategies to support patient involvement in genomic testing decisions are needed, particularly among practices in low-resource settings.

The Prototypes of Tobacco Users Scale (POTUS) for Cigarette Smoking and E-Cigarette Use: Development and Validation

Endorsing prototypes of cigarette smokers predicts cigarette smoking, but less is known about prototypes of users of other tobacco products. Our study sought to establish the reliability and validity of a measure of prototypes of smokers and e-cigarette users. Participants were from a national survey of smokers and non-smokers (n = 1414), a randomized clinical trial (RCT) of adult smokers (n = 2149), and adolescent children of adults in the trial (n = 112). The Prototypes of Tobacco Users Scale (POTUS) has four positive adjectives (cool, sexy, smart, and healthy) and four negative adjectives (disgusting, unattractive, immature, and inconsiderate) describing cigarette smokers and e-cigarette users. Confirmatory factor analyses identified a two-factor solution. The POTUS demonstrated strong internal consistency reliability in all three samples (median α = 0.85) and good test-retest reliability among adults in the RCT (median r = 0.61, 1-4 weeks follow-up). In the RCT, smokers more often agreed with negative prototypes for smokers than for e-cigarette users (mean = 2.03 vs. 1.67, p < 0.05); negative prototypes at baseline were also associated with more forgoing of cigarettes and making a quit attempt at the end of the trial (Week 4 follow-up). The POTUS may be useful to public health researchers seeking to design interventions that reduce tobacco initiation or cessation through the manipulation of tobacco user prototypes.

Abstract C016: Racial differences in the incidence of fatal prostate cancer in two countries: An ecological comparison of the United States and England

Background: Differential uptake of prostate-specific antigen (PSA) testing in the US and UK has been linked to between-country differences in prostate cancer incidence. In the US, men of African ancestry have been shown to have a higher incidence of prostate cancer that is ultimately fatal compared with men of European ancestry, thus prompting calls for precision prevention approaches to screening. To assess whether temporal and racial differences are evident in the UK, we assessed the incidence of fatal prostate cancer in the US and England during a period of evolving screening recommendations and practices in both countries.

Methods: Using data from the Surveillance, Epidemiology, and End Results program and Public Health England's National Cancer Registration and Analysis Service, we identified prostate cancer patients newly diagnosed between 1995 and 2005, aged 45-84 years old. We defined fatal prostate cancer as death attributed to the disease within 10 years of diagnosis. To evaluate incidence trends across the 11-year study period, we used age-period-cohort modeling to calculate estimated annual percentage change (EAPC) and joinpoint regression analysis to identify periods of significant change.

Results: In the US, 9% (n=38,409) of the 429,541 prostate cancer cases were fatal, compared with 17% (n=39,249) of the 228,615 cases in England. The age-adjusted incidence of fatal prostate cancer declined in the US by -4.2% per year (95%CI: -4.6%, -3.8%) and increased in England by 7.7% per year (95%CI:7.2%, 8.3%). From 2002-2005, the US experienced a more rapid decline in the incidence of fatal disease (EAPC = -6.4%; 95%CI: -8.3%, -4.5%) while rates in England continued to increase, albeit to a lesser degree (EAPC = 4.3%; 95%CI: -0.1%, 8.9%). Temporal trends for each country did not differ by race. However, a black-to-white difference persisted across the study period, with black men in both the US and England experiencing 2-to-3-fold higher incidence rates of fatal prostate cancer compared with white men.

Conclusions: During a period of increased PSA testing in the US and relatively low, but growing, use in England, we observed opposing trends for the incidence of fatal prostate cancer between the two countries. Our ecological study suggests that country-specific screening practices may influence temporal trends for the incidence of fatal prostate cancer similarly for black and white men, though a disparity persists in the absolute rate of disease occurrence between the two groups.

Citation Format: Eboneé N. Butler, Scott P. Kelly, Victoria H. Coupland, Philip R. Rosenberg, Michael B. Cook. Racial differences in the incidence of fatal prostate cancer in two countries: An ecological comparison of the United States and England [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C016.

Abstract D115: The interplay between rurality-urbanicity and race in prostate cancer risk, treatment, and survival in the United States

Background. In this study, we compared prostate cancer incidence and survival between rural and urban settings in the US, using a recently released census-tract rurality-urbanicity metric that serves as a proxy for geographical access to care. We also examined the associations between rurality and receipt of definitive treatment and further examined whether rural-urban status serves as an explanatory factor for observed race differences in prostate cancer incidence, treatment, and survival. Methods. Using data from the Surveillance, Epidemiology, and End Results program we identified prostate cancer patients newly diagnosed between 2000 and 2015, aged 45 years and older. Patients were classified as residing in a ‘rural’ or ‘urban’ setting based on the US Department of Agriculture’s 2-level Rural Urban Commuting Area (RUCA) measure. We defined ‘definitive treatment’ as receipt of radical prostatectomy (RP) among patients diagnosed with locoregional disease. To compare rural and urban settings we estimated relative measures for prostate cancer incidence, odds of treatment receipt, and prostate cancer survival using Poisson, logistic, and Cox regression models, respectively. We adjusted regression models for age, race, stage, or treatment, where applicable. Results. Between 2000 and 2015, men in the rural US were slightly less likely to be diagnosed with prostate cancer when compared with urban US men (incidence rate ratio (IRR) = 0.89; 95% CI: 0.88, 0.90), but were at higher risk of prostate cancer death (hazard ratio (HR) = 1.16; 95% CI: 1.13, 1.19). Patients diagnosed with locoregional disease in rural settings were also less likely to receive RP compared with their urban counterparts (odds ratio (OR) = 0.91; 95% CI: 0.89, 0.92) and were more likely to receive non-radical surgical interventions (OR = 1.31; 95% CI: 1.28, 1.35). In general, race differences were not evident by rural-urban status. Black men, however, were more likely to receive a prostate cancer diagnosis irrespective of geographical setting when compared with white men (rural IRR = 1.50; 95% CI: 1.46, 1.54 and urban IRR = 1.69; 95% CI: 1.64, 1.73). Black men were also substantially less likely to receive RP (OR = 0.49; 95% CI: 0.48, 0.49). With respect to survival, Asian or Pacific Islander men were at lower risk of prostate cancer death compared with white men (HR = 0.78; 95% CI: 0.75, 0.81). By contrast, American Indian/Alaskan Native and black men had the highest risks of death (HR = 1.26; 95% CI: 1.11, 1.43 and HR = 1.25; 95% CI: 1.22, 1.28, respectively). Conclusions. Observed differences in prostate cancer incidence, treatment, and survival may reflect spatial differences in access to cancer prevention and cancer care. Rural-urban status does not appear to modify racial/ethnic differences in prostate cancer incidence and survival.

Citation Format: Eboneé N Butler, Michael B Cook. The interplay between rurality-urbanicity and race in prostate cancer risk, treatment, and survival in the United States [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D115.

Fatal prostate cancer incidence trends in the United States and England by race, stage, and treatment

Background

Differential uptake of prostate-specific antigen testing in the US and UK has been linked to between-country differences for prostate cancer incidence. We examined stage-specific fatal prostate cancer incidence trends in the US and England, by treatment and race/ethnicity.

Methods

Using data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program and Public Health England’s National Cancer Registration and Analysis Service, we identified prostate cancer patients diagnosed between 1995 and 2005, aged 45–84 years. Fatal prostate cancer was defined as death attributed to the disease within 10 years of diagnosis. We used age–period–cohort models to assess trends in fatal prostate cancer incidence.

Results

Fatal prostate cancer incidence declined in the US by −7.5% each year and increased in England by 7.7% annually. These trends were primarily driven by locoregional disease in the US and distant disease in England. Black men in both countries had twofold to threefold higher fatal prostate cancer incidence rates, when compared with their white counterparts; however, receipt of radical prostatectomy lessened this disparity.

Conclusions

We report a significant increasing rate of fatal prostate cancer incidence among English men. The black–white racial disparity appears pervasive but is attenuated among those who received radical prostatectomy in the US.

Overall and abdominal obesity and prostate cancer risk in a West African population: An analysis of the Ghana Prostate Study

Obesity has been associated with an increased risk of advanced prostate cancer. However, most studies have been conducted among North American and European populations. Prostate cancer mortality appears elevated in West Africa, yet risk factors for prostate cancer in this region are unknown. We thus examined the relationship between obesity and prostate cancer using a case-control study conducted in Accra, Ghana in 2004 to 2012. Cases and controls were drawn from a population-based sample of 1037 men screened for prostate cancer, yielding 73 cases and 964 controls. An additional 493 incident cases were recruited from the Korle-Bu Teaching Hospital. Anthropometric measurements were taken at enrollment. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR) and prostate cancer, adjusting for potential confounders. The mean BMI was 25.1 kg/m² for cases and 24.3 kg/m² for controls. After adjustment, men with BMI ≥ 30 kg/m² had an increased risk of prostate cancer relative to men with BMI < 25 kg/m² (OR 1.86, 95% CI 1.11-3.13). Elevated WC (OR 1.76, 95% CI 1.24-2.51) and WHR (OR 1.46, 95% CI 0.99-2.16) were also associated with prostate cancer. Associations were not modified by smoking status and were evident for low- and high-grade disease. These findings indicate that overall and abdominal obesity are positively associated with prostate cancer among men in Ghana, implicating obesity as a potentially modifiable risk factor for prostate cancer in this region.

Prediagnostic Smoking Is Associated with Binary and Quantitative Measures of ER Protein and ESR1 mRNA Expression in Breast Tumors

Background: Smoking is a possible risk factor for breast cancer and has been linked to increased risk of estrogen receptor-positive (ER⁺) disease in some epidemiologic studies. It is unknown whether smoking has quantitative effects on ER expression.Methods: We examined relationships between smoking and ER expression from tumors of 1,888 women diagnosed with invasive breast cancer from a population-based study in North Carolina. ER expression was characterized using binary (±) and continuous measures for ER protein, ESR1 mRNA, and a multigene luminal score (LS) that serves as a measure of estrogen signaling in breast tumors. We used logistic and linear regression models to estimate temporal and dose-dependent associations between smoking and ER measures.Results: The odds of ER⁺, ESR1⁺, and LS⁺ tumors among current smokers (at the time of diagnosis), those who smoked 20 or more years, and those who smoked within 5 years of diagnosis were nearly double those of nonsmokers. Quantitative levels of ESR1 were highest among current smokers compared with never smokers overall [mean (log₂) = 9.2 vs. 8.7, P < 0.05] and among ER⁺ cases; however, we did not observe associations between smoking measures and continuous ER protein expression.Conclusions: In relationship to breast cancer diagnosis, recent smoking was associated with higher odds of the ER⁺, ESR1⁺, and LS⁺ subtype. Current smoking was associated with elevated ESR1 mRNA levels and an elevated LS, but not with altered ER protein.Impact: A multigene LS and single-gene ESR1 mRNA may capture tumor changes associated with smoking. Cancer Epidemiol Biomarkers Prev; 27(1); 67-74. ©2017 AACR.

Abstract 4264: Smoking exposure and quantitative levels of estrogen-receptor expression in ER+ breast tumors

Introduction: Smoking is a suspected risk factor for breast cancer and has been linked to increased risk of estrogen-receptor positive (ER+) disease in some epidemiologic studies. Cigarette smoke has also been shown to have antiestrogenic effects, leading to a potentially contradictory hypothesis that smoking would lead to decreased risk of breast tumors driven by estrogen-signaling. Binary classification of breast tumors with respect to ER may mask quantitative associations between smoking and ER expression. Methods: Using data from the Carolina Breast Cancer Study (CBCS), we examined relationships between smoking and quantitative levels of ER expression from tumors of 1,297 women with ER+ disease (i.e., ≥ 10% of tumor cells ER+ by immunohistochemical analysis). We used multinomial logistic regression to estimate associations between categorical measures of smoking and quartiles of ER protein or ESR1 mRNA expression, represented by odds ratios (OR) and 95% confidence intervals (95% CI). We also examined associations between smoking and quantitative ER levels among women with ER+ breast tumors, stratified by menopausal status. Multivariate regression models include adjustment for age, race, stage, grade, and tumor size. Results: Quantitative ESR1 was positively associated with any history of smoking (i.e., current at time of diagnosis or former smoking) (OR: 1.96 and 95% CI: 1.24 to 3.10). In addition, smoking more than 1 pack of cigarettes per day was associated with high ESR1 expression (OR: 3.19 and 95% CI: 1.29 to 7.91) as was smoking duration of &gt; 20 years (OR: 2.08 and 95% CI: 1.16 to 3.74). Among former smokers, we observed higher ESR1 expression among those who quit 5-10 years prior to diagnosis. The magnitudes of association between smoking and quantitative levels of ESR1 expression were similar for both pre- and post-menopausal women, but were not reflected in similar association on the protein level. Conclusions: Among women with ER+ breast cancer, smoking dose and duration was positively associated with elevated ESR1 mRNA levels, regardless of menopausal status. Absence of this association for protein suggests that ESR1 RNA merits further consideration, but may suggest that ESR1 RNA more sensitively captures biological differences than ER protein expression.

Citation Format: Eboneé N. Butler, John A. Baron, Jeannette T. Bensen, Mengjie Chen, Kathleen Conway, Andrew F. Olshan, Melissa Troester. Smoking exposure and quantitative levels of estrogen-receptor expression in ER+ breast tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4264. doi:10.1158/1538-7445.AM2017-4264

Active smoking and risk of Luminal and Basal-like breast cancer subtypes in the Carolina Breast Cancer Study

PURPOSE

Growing evidence suggests an association between active cigarette smoking and increased breast cancer risk. However, the weak magnitude of association and conflicting results have yielded uncertainty and it is unknown whether associations differ by breast cancer subtype.

METHODS

Using population-based case-control data from phases I and II of the Carolina Breast Cancer Study, we examined associations between self-reported measures of smoking and risk of Luminal and Basal-like breast cancers. We used logistic regression models to estimate case-control odds ratios (OR) and 95 % confidence intervals (CI).

RESULTS

Ever smoking (current and former) was associated with a weakly increased risk of Luminal breast cancer (OR 1.12, 95 % CI 0.92-1.36) and was not associated with risk of Basal-like breast cancer (OR 0.96, 95 % CI 0.69-1.32). Similarly, smoking duration of more than 20 years was associated with increased risk of Luminal (OR 1.51, 95 % CI 1.19-1.93), but not Basal-like breast cancer (OR 0.90, 95 % CI 0.57-1.43). When stratified by race, elevated odds ratios between smoking and Luminal breast cancer risk were found among black women across multiple exposure measures (ever smoking, duration, and dose); conversely, among white women odds ratios were attenuated or null.

CONCLUSIONS

Results from our study demonstrate a positive association between smoking and Luminal breast cancer risk, particularly among black women and women with long smoking histories. Addressing breast cancer heterogeneity in studies of smoking and breast cancer risk may elucidate associations masked in prior studies.

Receipt of chemotherapy among medicare patients with cancer by type of supplemental insurance

PURPOSE

Medicare beneficiaries with cancer bear a greater portion of their health care costs, because cancer treatment costs have increased. Beneficiaries have supplemental insurance to reduce out-of-pocket costs; those without supplemental insurance may face barriers to care. This study examines the association between type of supplemental insurance coverage and receipt of chemotherapy among Medicare patients with cancer who, per National Comprehensive Cancer Network treatment guidelines, should generally receive chemotherapy.

PATIENTS AND METHODS

This retrospective, observational study included 1,200 Medicare patients diagnosed with incident cancer of the breast (stage IIB to III), colon (stage III), rectum (stage II to III), lung (stage II to IV), or ovary (stage II to IV) from 2000 to 2005. Using the National Cancer Institute Patterns of Care Studies and linked SEER-Medicare data, we determined each Medicare patient's supplemental insurance status (private insurance, dual eligible [ie, Medicare with Medicaid], or no supplemental insurance), consultation with an oncologist, and receipt of chemotherapy. Using adjusted logistic regression, we evaluated the association of type of supplemental insurance with oncologist consultation and receipt of chemotherapy.

RESULTS

Dual-eligible patients were significantly less likely to receive chemotherapy than were Medicare patients with private insurance. Patients with Medicare only who saw an oncologist had comparable rates of chemotherapy compared with Medicare patients with private insurance.

CONCLUSION

Dual-eligible Medicare beneficiaries received recommended cancer chemotherapy less frequently than other Medicare beneficiaries. With the increasing number of Medicaid patients under the Affordable Care Act, there will be a need for patient navigators and sufficient physician reimbursement so that low-income patients with cancer will have access to oncologists and needed treatment.

Prevalence of physical activity and sedentary behavior among stroke survivors in the United States

BACKGROUND

The risk of stroke is greatest among adults who have experienced a previous stroke, transient ischemic attack, or myocardial infarction. Physical activity may reduce the secondary risk of stroke through mediating effects on blood pressure, vasoconstriction, and circulating lipid concentrations; however, little is known about the prevalence of physical activity and sedentary behavior among stroke survivors in the United States.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES), we describe self-reported and objectively measured physical activity and sedentary behavior among adults with a self-reported history of stroke. We also contrast physical activity among stroke survivors with that of adults without stroke (unexposed) to illustrate expected behavior in the absence of disease.

RESULTS

Fewer participants with stroke met weekly physical activity guidelines as outlined in the 2008 Physical Activity Guidelines for Americans when compared with unexposed participants (17.9% vs 25.0%) according to self-reported data. In addition, participants with stroke reported less moderate (46.1% vs 54.7%) and vigorous (9.1% vs 19.6%) leisure activity compared with unexposed participants. As measured by accelerometer, time since diagnosis was inversely associated with physical activity engagement, and participants with stroke recorded more daily hours of sedentary behavior compared with unexposed participants (10.1 hours vs 8.9 hours).

CONCLUSION

Findings from this study provide a basis for future work seeking to measure the impact of physical activity on the secondary prevention of stroke by characterizing the prevalence of physical activity and sedentary behavior among stroke survivors in the United States.

Patterns of colorectal cancer care in Europe, Australia, and New Zealand

Colorectal cancer is the second most common cancer in women and the third most common in men worldwide. In this study, we used MEDLINE to conduct a systematic review of existing literature published in English between 2000 and 2010 on patterns of colorectal cancer care. Specifically, this review examined 66 studies conducted in Europe, Australia, and New Zealand to assess patterns of initial care, post-diagnostic surveillance, and end-of-life care for colorectal cancer. The majority of studies in this review reported rates of initial care, and limited research examined either post-diagnostic surveillance or end-of-life care for colorectal cancer. Older colorectal cancer patients and individuals with comorbidities generally received less surgery, chemotherapy, or radiotherapy. Patients with lower socioeconomic status were less likely to receive treatment, and variations in patterns of care were observed by patient demographic and clinical characteristics, geographical location, and hospital setting. However, there was wide variability in data collection and measures, health-care systems, patient populations, and population representativeness, making direct comparisons challenging. Future research and policy efforts should emphasize increased comparability of data systems, promote data standardization, and encourage collaboration between and within European cancer registries and administrative databases.

Patterns of colorectal cancer care in the United States and Canada: a systematic review

Colorectal cancer is the third most common cancer in the United States and Canada. Given the high incidence and increased survival of colorectal cancer patients, prevalence is increasing over time in both countries. Using MEDLINE, we conducted a systematic review of the literature published between 2000 and 2010 to describe patterns of colorectal cancer care. Specifically we examined data sources used to obtain treatment information and compared patterns of cancer-directed initial care, post-diagnostic surveillance care, and end-of-life care among colorectal cancer patients diagnosed in the United States and Canada. Receipt of initial treatment for colorectal cancer was associated with the anatomical position of the tumor and extent of disease at diagnosis, in accordance with consensus-based guidelines. Overall, care trends were similar between the United States and Canada; however, we observed differences with respect to data sources used to measure treatment receipt. Differences were also present between study populations within country, further limiting direct comparisons. Findings from this review will allow researchers, clinicians, and policy makers to evaluate treatment receipt by patient, clinical, or system characteristics and identify emerging trends over time. Furthermore, comparisons between health-care systems in the United States and Canada can identify disparities in care, allow the evaluation of different models of care, and highlight issues regarding the utility of existing data sources to estimate national patterns of care.

Cross-reactive antibody responses to the 2009 pandemic H1N1 influenza virus

BACKGROUND

A new pandemic influenza A (H1N1) virus has emerged, causing illness globally, primarily in younger age groups. To assess the level of preexisting immunity in humans and to evaluate seasonal vaccine strategies, we measured the antibody response to the pandemic virus resulting from previous influenza infection or vaccination in different age groups.

METHODS

Using a microneutralization assay, we measured cross-reactive antibodies to pandemic H1N1 virus (2009 H1N1) in stored serum samples from persons who either donated blood or were vaccinated with recent seasonal or 1976 swine influenza vaccines.

RESULTS

A total of 4 of 107 persons (4%) who were born after 1980 had preexisting cross-reactive antibody titers of 40 or more against 2009 H1N1, whereas 39 of 115 persons (34%) born before 1950 had titers of 80 or more. Vaccination with seasonal trivalent inactivated influenza vaccines resulted in an increase in the level of cross-reactive antibody to 2009 H1N1 by a factor of four or more in none of 55 children between the ages of 6 months and 9 years, in 12 to 22% of 231 adults between the ages of 18 and 64 years, and in 5% or less of 113 adults 60 years of age or older. Seasonal vaccines that were formulated with adjuvant did not further enhance cross-reactive antibody responses. Vaccination with the A/New Jersey/1976 swine influenza vaccine substantially boosted cross-reactive antibodies to 2009 H1N1 in adults.

CONCLUSIONS

Vaccination with recent seasonal nonadjuvanted or adjuvanted influenza vaccines induced little or no cross-reactive antibody response to 2009 H1N1 in any age group. Persons under the age of 30 years had little evidence of cross-reactive antibodies to the pandemic virus. However, a proportion of older adults had preexisting cross-reactive antibodies.

Triple negative breast cancer confers higher recurrence rates after breast conserving therapy

Abstract #5127

Purpose&#x2028; There has been a recent surge of information regarding the treatment outcomes for women with estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative breast cancer; known as the triple negative (TN) subtype. The purpose of this study is to evaluate the impact of these receptor expressions on local, regional and distant recurrences, and overall survival (OS) in patients undergoing breast conserving therapy (BCT).&#x2028; Patients and Methods&#x2028; The study population included 475 primary invasive female breast cancer patients (excluding Stage IV); who were residents of Fulton-Dekalb counties in Atlanta when diagnosed in 2003-2004 and treated within the Emory University affiliated hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.4 years. The endpoints of the study were local, regional and distant recurrences, and OS. Tumors were subgrouped as: ER-/PR-/HER2- (TN), ER+/PR+/HER2-, ER+/PR+/HER2+, ER+/PR+/HER2-. Chi-square and Fisher exact tests were employed.&#x2028; Results&#x2028; For the entire population, median age was 58 years. TN tumors accounted for 17% of the cases. Of the TN patients, 78% were African-American (p&lt;0.01) and 40% had BCT. The majority of TN tumors were high grade (71%), p&lt; 0.01. Total recurrence was 33% among the TN patients vs. 14% in the combined non-TN patient group, p&lt; 0.01. Death occurred among 29% of TN vs. 14% of non-TN, p&lt; 0.01.&#x2028; For the patients that were treated with BCT, 94% of TN patients completed their adjuvant radiation therapy and 73% received chemotherapy. Of those receiving BCT, recurrence was 28% for TN patients and 6% for non-TN patients (p&lt;0.01). Local recurrence was 9% and 4% for TN and non-TN patients, respectively and distant metastatic rate was 16% versus 2% respectively (p&lt; 0.01). There were no regional recurrences in the BCT group. Time to recurrence, OS, time to death, and breast cancer specific death did not differ between the two groups.&#x2028; Conclusion&#x2028; A significant increase in local recurrence and distant metastatic rates were observed after BCT among patients diagnosed with TN breast cancers; however there was not a significant short-term survival difference between the TN and non-TN receptor groups. The complexity of this patient population within the conventional treatment algorithm warrants further investigation to reduce local and distant recurrences.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5127.

HEPES may stimulate cultured endothelial cells to make growth-retarding oxygen metabolites

Zwitterion buffers are often used to modulate the pH of cell culture medium but their effect on cultured cells is controversial. We found that addition of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) caused superoxide dismutase (SOD) inhibitable increases in nitroblue tetrazolium dye reduction and SOD and catalase inhibitable decreases in the growth of cultured bovine pulmonary artery endothelial cells. The findings suggest that HEPES stimulates endothelial cells to make toxic oxygen metabolites that contribute to decreased cell growth.

Hyperoxia damages cultured endothelial cells causing increased neutrophil adherence

Exposure of cultured bovine pulmonary artery endothelial cells to hyperoxia (95% O2) caused cellular injury manifested by decreased growth rates and release of cytoplasmic lactic dehydrogenase (LDH). In addition, a greater number of polymorphonuclear leukocytes (PMN) adhered to endothelial cells that had been exposed to hyperoxia for 24 or 48 h than to control endothelial cells that had been exposed to normoxia (15% O2). Direct endothelial cell injury from hyperoxia may contribute to vascular damage and the increased PMN accumulation seen in lungs of animals exposed to hyperoxia.