Mammography Compliance for Arizona and New Mexico Hispanic and American Indian Women 2016-2018

Hispanic and American Indian (AI) women experience lower breast cancer incidence than non-Hispanic White (NHW) women, but later-stage diagnoses and lower survival rates, suggesting issues with screening and healthcare access. Between 1999-2015, NHW breast cancer incidence decreased by 10% but increased by 8% for AI women. This study used 2016 and 2018 Behavioral Risk Factor Surveillance System data for Arizona and New Mexico to explore mammography screening. Analyses included Hispanic, AI, and NHW women aged ≥40 years (n = 12,830) to calculate age-specific compliance by race/ethnicity, logistic regression, and adjusted and sample-weighted evaluated associations between compliance and socio-economic covariates. In total, 75.1% of Hispanic women aged 50-74 reported mammography in the past two years (United States Preventive Services Task Force compliant) compared to 73.9% of NHW and 71.0% of AI women. Women who reported doctor visits in the past 12 months were likelier to comply than those without (AOR = 4.2 for Hispanic, 2.9 for AI, and 3.2 for NHW women). Reporting access to a personal doctor was related to compliance, except for AI women. While screening compliance was over 74%, visiting a healthcare provider in the past 12 months was essential. AI women reported issues that suggest unique challenges when deciding on mammography.

Antibiotic Resistance Rates for Helicobacter pylori in Rural Arizona: A Molecular-Based Study

Helicobacter pylori (H. pylori) is a common bacterial infection linked to gastric malignancies. While H. pylori infection and gastric cancer rates are decreasing, antibiotic resistance varies greatly by community. Little is known about resistance rates among rural Indigenous populations in the United States. From 2018 to 2021, 396 endoscopy patients were recruited from a Northern Arizona clinic, where community H. pylori prevalence is near 60%. Gastric biopsy samples positive for H. pylori (n = 67) were sequenced for clarithromycin- and metronidazole-associated mutations, 23S ribosomal RNA (23S), and oxygen-insensitive NADPH nitroreductase (rdxA) regions. Medical record data were extracted for endoscopic findings and prior H. pylori history. Data analysis was restricted to individuals with no history of H. pylori infection. Of 49 individuals, representing 64 samples which amplified in the 23S region, a clarithromycin-associated mutation was present in 38.8%, with T2182C being the most common mutation at 90%. While the prevalence of metronidazole-resistance-associated mutations was higher at 93.9%, the mutations were more variable, with D95N being the most common followed by L62V. No statistically significant sex differences were observed for either antibiotic. Given the risk of treatment failure with antibiotic resistance, there is a need to consider resistance profile during treatment selection. The resistance rates in this population of American Indian patients undergoing endoscopy are similar to other high-risk populations. This is concerning given the high H. pylori prevalence and low rates of resistance testing in clinical settings. The mutations reported are associated with antibiotic resistance, but clinical resistance must be confirmed.

Associations of Prenatal Agricultural Farm Work with Fetal Overgrowth and Pregnancy Complications in State of Arizona Birth Records

OBJECTIVE

The purpose of this study is to examine fetal growth outcomes from agricultural worker households.

METHODS

Using Arizona 2006 to 2013 birth certificates with parental occupation, we identified N = 623,185 live births by agricultural household status. Logistic regression models estimated adjusted odds ratios (aORs) for macrosomia (>4000 g), postterm birth (>41 weeks), low birth weight (<2500 g), preterm birth (<37 weeks), large for GA, small for GA, and 5-minute APGAR (<7).

RESULTS

Newborns of agricultural households (n = 6371) had a higher risk of macrosomia (aOR, 1.15; 95% CI, 1.05-1.26), large for GA (aOR, 1.12; 95% CI, 1.03-1.22), postterm birth (aOR, 1.20; 95% CI, 1.09-1.33), and low 5-minute APGAR (aOR, 1.39; 95% CI, 1.07-1.81), whereas low birth weight (aOR, 0.85; 95% CI, 0.76-0.96) and preterm birth (aOR, 0.82; 95% CI, 0.74-0.92) were inversely related.

CONCLUSIONS

Having an agriculture working parent increased the likelihood of fetal overgrowth and low APGAR.

A meta-analysis of sunburn and basal cell carcinoma risk

Basal cell carcinoma (BCC) is the most common cancer in the United States. Sunburn is a modifiable risk factor for BCC. The objective of this project was to synthesize research on BCC and sunburn to quantify the impact and severity of sunburn at different life stages on BCC risk in the general population. A systematic literature search of four electronic databases was conducted and data were extracted by two independent reviewers using standardized forms. Data from 38 studies were pooled using both dichotomous and dose-response meta-analytic methods. BCC risk increased with ever experiencing a sunburn in childhood (OR=1.43, 95% CI: 1.19, 1.72) and with ever experiencing a sunburn in life (OR= 1.40, 95% CI: 1.02, 1.45). Every five sunburns experienced per decade in childhood increased BCC risk by 1.86 (95% CI: 1.73, 2.00) times. Every five sunburns experienced per decade in adulthood increased BCC risk by 2.12 (95% CI: 1.75, 2.57) times and every five sunburns per decade of life increased BCC risk by 1.91 (95% CI: 1.42, 2.58) times. The data on sunburn exposure and BCC show that an increase in number of sunburns at any age increased the risk of BCC. This may inform future prevention efforts.

Helicobacter pylori treatment knowledge, access and barriers: A cross-sectional study

BACKGROUND

Helicobacter pylori (Hp) is among the most common bacterial infections in the world and one of the most common infectious agents linked to malignancy, gastric cancer (GC). Within the US there is high disparity in the rates of Hp infection and associated diseases. Hp infection is treatable, and knowledge may influence screening and treatment seeking behaviors.

MATERIALS AND METHODS

In this cross-sectional study of 1042 respondents recruited from the Online Amazon MTurk platform, we sought to assess baseline knowledge of Hp and to gain insight into barriers related to Hp care.

RESULTS

Just over half (52.3%) reported some prior knowledge of Hp with 11.7% (n = 122) reporting being treated for Hp themselves and 21.4% reporting family members diagnosed with Hp. Of respondents reporting prior treatment, 95 (78%) reported GI upset and 27 (21%) reported not completing medications. Specific to Hp and GC, 70% indicated that a belief that the treatment was worse than the symptoms would affect their willingness to seek care, while 81% indicated knowing Hp can cause GC would affect their treatment decisions and knowing their gastric symptoms were caused by Hp would affect their willingness to receive care.

CONCLUSIONS

Knowledge of Hp in this US sample of online respondents is low and self-reported difficulties with treatment compliance is high. Increasing awareness of this infection and addressing the challenges to treatment compliance could potentially reduce rates of Hp antibiotic resistance and progression to GC or other complications of Hp infection.

Factors Associated with Cancer Screening Among Hopi Men

Cancer screening rates remain low among American Indian men, and cancer screening behaviors and barriers to cancer screening among American Indian men are not well understood. This study evaluated cancer screening behaviors in 102 Hopi men who were 50 years of age or older from the Hopi Survey of Cancer and Chronic Disease. Reported cancer screening frequencies were 15.7%, 45.1%, and 35.3% for fecal occult blood test (FOBT), colonoscopy, and prostate-specific antigen (PSA) test, respectively. Among men who reported having had a FOBT, 81.2% had the test more than 1 year ago. Among men who reported a colonoscopy, 60.8% had colonoscopy within the past 3 years. Similarly, among men who reported having had PSA, 72.3% had PSA within the past 3 years. "No one told me" was the most common answer for not undergoing FOBT (33.7%), colonoscopy (48.2%), and PSA (39.4%). Men who reported having had a PSA or digital rectal exam were three times as likely to also report having a FOBT or colonoscopy (odds ratio [OR] 3.19, 95% confidence interval [CI]: 1.21-8.46). Younger age (< 65) was associated with reduced odds of ever having prostate cancer screening (OR 0.28, 95% CI: 0.10-0.77). Ever having colorectal cancer screening and previous diagnosis of cancer increased odds of ever having prostate cancer screening (OR 3.15, 95% CI: 1.13-8.81 and OR 5.28, 95% CI: 1.15-24.18 respectively). This study illustrates the importance of community cancer education for men to improve cancer screening participation.

Racial/Ethnic Disparities in Health and Life Insurance Denial Due to Cancer among Cancer Survivors

PURPOSE OF THE STUDY

This study examined racial/ethnic differences in health and life insurance denial due to cancer among cancer survivors after the passage of the Affordable Care Act (ACA).

METHODS

A cross sectional study was conducted using Behavioral Risk Factor Surveillance System data from 2012 through 2020. The dependent variable asked: "Were you ever denied health insurance or life insurance coverage because of your cancer?" Cancer survivors were included if they were diagnosed with cancer after the Affordable Care Act (N=14,815). Descriptive statistics using weighted percentages summarized the results. Logistic regressions provided odds of insurance denial due to cancer across racial/ethnic groups: Non-Hispanic White, Black, and Other/mixed race; and Hispanic. Models adjusted for age, sex, income, and employment status. Interaction terms for age, sex, income, and employment were included in regression models to assess for effect modification.

RESULTS

Weighted chi-squares identified statistically significant differences (p<0.05) between those who were denied or not denied insurance across sex, age, race/ethnicity, income, and employment. Adjusted weighted logistic regressions found significantly higher odds of insurance denial for Blacks (OR:3.01, 95%CI:1.78, 5.08), Other/mixed race (OR:2.10, 95%CI: 1.13, 3.90), and Hispanics (OR:2.16, 95%CI:1.05, 4.46) compared to Non-Hispanic Whites. Sex, income, and employment status were significant effect modifiers. Compared to White women, Black women were significantly more likely to be denied health and life insurance. Compared to Whites with incomes >$25K to <$50K and >$50K to <$75K, Blacks were more likely to be denied insurance (OR:3.50, 95%CI:1.42, 8.66 and OR:7.72, 95%CI: 2.40, 24.81).

CONCLUSIONS

Despite health insurance denial for pre-existing conditions being illegal under the ACA, cancer survivors report racial/ethnic disparities in health and life insurance denial due to their cancer diagnosis. This denial may be particularly harmful for people of color who are already financially vulnerable due to their cancer diagnosis and exacerbate racial/ethnic cancer disparities.

"Nobody Is Talking About It": Diné (Navajo) Communities Speak About Stomach Cancer and Helicobacter pylori Infections

Stomach cancer is the third leading cause of cancer death globally. Helicobacter pylori plays a role in the healthy human gut, but is also associated with multiple chronic diseases, including stomach cancer. Though H. pylori prevalence is declining in parts of the world, it remains high among certain populations. In Arizona, stomach cancer rates are 3-4 times higher among the Navajo Nation population as compared with the non-Hispanic white population. This pilot project assessed adult Diné (Navajo) individuals' understanding and awareness regarding H. pylori infection and stomach cancer. Focus groups were held in three Diné communities. Data were analyzed thematically using a multi-investigator consensus approach. Participants had limited knowledge of H. pylori infection and stomach cancer and perceived local medical providers as also having limited knowledge on these conditions. Participants described poor health care experiences, structural inequalities, and environmental concerns and associated these with H. pylori infection and stomach cancer. This study highlights the need for additional research and education on current knowledge and perceptions of stomach cancer and H. pylori infections in Navajo Nation.

Helicobacter pylori Prevalence and Risk Factors in Three Rural Indigenous Communities of Northern Arizona

Helicobacter pylori (H. pylori) is one of the most common bacterial stomach infections and is implicated in a majority of non-cardia gastric cancer. While gastric cancer has decreased in the United States (US), the incidence in the Navajo Nation is nearly four times higher than surrounding Non-Hispanic White populations. Little is known about H. pylori prevalence in this population or other Indigenous communities in the lower 48 states. In this cross-sectional study, 101 adults representing 73 households from three Navajo Nation chapter communities completed surveys and a urea breath test for active H. pylori. Accounting for intrahousehold correlation, H. pylori prevalence was 56.4% (95% CI, 45.4–66.8) and 72% of households had at least one infected person. The odds of having an active infection in households using unregulated water were 8.85 (95% CI, 1.50–53.38) that of the use of regulated water, and males had 3.26 (95% CI, 1.05–10.07) higher odds than female. The prevalence of H. pylori in Navajo is similar to that seen in Alaska Natives. Further investigation into factors associated with prevention of infection is needed as well as understanding barriers to screening and treatment.

Household and behavioral determinants of indoor PM2.5 in a rural solid fuel burning Native American community

Indoor and outdoor concentrations of PM_2.5 were measured for 24 h during heating and non-heating seasons in a rural solid fuel burning Native American community. Household building characteristics were collected during the initial home sampling visit using technician walkthrough questionnaires, and behavioral factors were collected through questionnaires by interviewers. To identify seasonal behavioral factors and household characteristics associated with indoor PM_2.5 , data were analyzed separately by heating and non-heating seasons using multivariable regression. Concentrations of PM_2.5 were significantly higher during the heating season (indoor: 36.2 μg/m³ ; outdoor: 22.1 μg/m³ ) compared with the non-heating season (indoor: 14.6 μg/m³ ; outdoor: 9.3 μg/m³ ). Heating season indoor PM_2.5 was strongly associated with heating fuel type, housing type, indoor pests, use of a climate control unit, number of interior doors, and indoor relative humidity. During the non-heating season, different behavioral and household characteristics were associated with indoor PM_2.5 concentrations (indoor smoking and/or burning incense, opening doors and windows, area of surrounding environment, building size and height, and outdoor PM_2.5 ). Homes heated with coal and/or wood, or a combination of coal and/or wood with electricity and/or natural gas had elevated indoor PM_2.5 concentrations that exceeded both the EPA ambient standard (35 μg/m³ ) and the WHO guideline (25 μg/m³ ).

Chronic kidney disease unawareness and determinants using 1999-2014 National Health and Nutrition Examination Survey Data

BACKGROUND

Although chronic kidney disease (CKD) affects 15% of the United States (US) population, <10% of the US CKD population is aware of their disease. This is significant as untreated CKD can progress to end-stage renal disease which would require dialysis or transplantation. This study aimed to provide updated information regarding US CKD unawareness.

METHODS

Data from the 1999-2014 National Health and Nutrition Examination Survey (NHANES) were used (n = 38 474); response rate > 70%. CKD self-report and lab-confirmed CKD were used to assess CKD unawareness. Adjusted logistic regression models examined association between unawareness and patient characteristics.

RESULTS

In individuals with lab-confirmed CKD (n = 7137, 14.3%), 91.5% answered 'no' to self-report question; in those without CKD, 1.1% answered 'yes' to self-report question. In those with lab-confirmed CKD, in the adjusted models, increased age [odds ratio (ORs), 1.03 (95%CI, 1.02-1.04)] and female sex [OR, 1.37 (95%CI, 1.08-1.72)] were statistically significantly associated with greater odds of being unaware of CKD.

CONCLUSION

These findings demonstrated high unawareness of disease status as there was a discrepancy between respondents' self-reported CKD diagnosis and lab-confirmed CKD. Older individuals and women may be more unaware of their CKD; these groups should be queried about reasons for increased unawareness.

Community transmission of multidrug-resistant tuberculosis is associated with activity space overlap in Lima, Peru

Background

Transmission of multidrug-resistant tuberculosis (MDRTB) requires spatial proximity between infectious cases and susceptible persons. We assess activity space overlap among MDRTB cases and community controls to identify potential areas of transmission.

Methods

We enrolled 35 MDRTB cases and 64 TB-free community controls in Lima, Peru. Cases were whole genome sequenced and strain clustering was used as a proxy for transmission. GPS data were gathered from participants over seven days. Kernel density estimation methods were used to construct activity spaces from GPS locations and the utilization distribution overlap index (UDOI) was used to quantify activity space overlap.

Results

Activity spaces of controls (median = 35.6 km², IQR = 25.1–54) were larger than cases (median = 21.3 km², IQR = 17.9–48.6) (P = 0.02). Activity space overlap was greatest among genetically clustered cases (mean UDOI = 0.63, sd = 0.67) and lowest between cases and controls (mean UDOI = 0.13, sd = 0.28). UDOI was positively associated with genetic similarity of MDRTB strains between case pairs (P < 0.001). The odds of two cases being genetically clustered increased by 22% per 0.10 increase in UDOI (OR = 1.22, CI = 1.09–1.36, P < 0.001).

Conclusions

Activity space overlap is associated with MDRTB clustering. MDRTB transmission may be occurring in small, overlapping activity spaces in community settings. GPS studies may be useful in identifying new areas of MDRTB transmission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05953-8.

Design of the Arizona CoVHORT: A Population-Based COVID-19 Cohort

This study is a prospective, population-based cohort of individuals with a history of SARS-CoV-2 infection and those without past infection through multiple recruitment sources. The main study goal is to track health status over time, within the diverse populations of Arizona and to identify the long-term consequences of COVID-19 on health and well-being. A total of 2,881 study participants (16.2% with a confirmed SARS-CoV-2 infection) have been enrolled as of December 22, 2020, with a target enrollment of 10,000 participants and a planned follow-up of at least 2 years. This manuscript describes a scalable study design that utilizes a wide range of recruitment sources, leveraging electronic data collection to capture and link longitudinal participant data on the current and emerging issues associated with the COVID-19 pandemic. The cohort is built within a collaborative infrastructure that includes new and established partnerships with multiple stakeholders, including the state's public universities, local health departments, tribes, and tribal organizations. Challenges remain for ensuring recruitment of diverse participants and participant retention, although the electronic data management system and timing of participant contact can help to mitigate these problems.

Resilience and Stress among Hopi Female Caregivers

Resilience and stress are important factors in the caregiving experience, but research has yet to examine their association among American Indian (AI) caregivers. This study examines resilience and stress in a group of Hopi female caregivers. Data came from the Hopi Adult Caregiver Survey (2017), which conducted interviews with 44 Hopi women who were providing care without remuneration to an adult family member. Measures included the abbreviated Connor-Davidson Resilience Scale (CD-RISC-10), the Perceived Stress Scale (PSS-10), and questions about caregiver characteristics, care recipient characteristics, social support/ community support, and cultural factors. Stress and resilience were looked at above the median (higher stress or higher resilience) and below the median (lower stress or lower resilience). Caregivers who reported relatively lower resilience were more likely to report that they lived separately from their care recipients and that all Hopis are expected to be caregivers. Caregivers who reported relatively higher stress reported a higher total number of caregiver difficulties, a poorer self-perception of their own health, use of a traditional healer in the past 5 years, and that females are expected to be caregivers. A regression analysis adjusting for age, education, and employment status indicated that higher resilience among the caregivers was significantly associated with lower stress. In light of these findings, programs working with AI caregivers may wish to explore whether supporting the resilience of these caregivers is a means towards limiting their stress.

Abstract PO-162: Helicobacter pylori in Native Americans in Northern Arizona

Background. Helicobacter pylori, one of the most common bacterial infections worldwide. Chronic infections are associated with gastritis, peptic ulcer, and gastric cancer. While H. pylori infections and gastric cancer are going down in the US, certain populations continue to experience high H. pylori prevalence of infection and a significant burden from stomach cancer. For example, in Arizona H. pylori prevalence of infection among the Navajo is 60% and gastric cancer is 3-4 times higher that of the white population. Objective: The aim of this work was to survey the presence of virulence factors (cagA and vacA) in H. pylori in the Navajo reservation and their association with gastric disease. Methods: The presence of the virulence genes, cagA and vacA in H. pylori was investigated in gastric biopsies from 97 patients attending the gastroenterology clinic in Winslow, AZ. Biopsies were collected from the antrum and fundus and used for histological examination and for molecular characterization. Molecular characterization was performed by looking at type and number of EPIYA motifs in cagA and presence of different alleles in the signal (s) and medium (m) regions of the vacA gene. Results: The infection rate in the biopsy samples was 22.9%. The cagA gene amplified in 76.9% of the cases and analysis of the 3′ region of cagA showed the predominant presence of the “Western CagA” type with the EPIYA-ABC motif (70.0%) the most prevalent. The vacA allele s1bm1 was the most prevalent (76.9%) followed by s2m2 (11.5%). CagA negative isolates were associated with gastritis or normal findings while EPIYA motifs ABCC were present in severe gastric disease. vacA s2m2 were associated with normal findings. Conclusions: In this population, we have found H. pylori genotypes with predominant cagA Western-type and ABC EPIYA motifs. The vacA s1m1 genotype was the most prevalent and seemed to be associated with gastritis. American Indian/Native American populations are at higher risk for gastric cancer than the general US population. It is important to better establish and quantify genotypes of H. pylori to identify bacterial factors involved in the high prevalence of H. pylori and associated disease among the Navajo population.

Citation Format: Fernando P. Monroy, Heidi E. Brown, Priscilla Sanderson, Gregory Jarrin, Mimi Mbegbu, Shari Kyman, Camenlita Chief, Robin B. Harris. Helicobacter pylori in Native Americans in Northern Arizona [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-162.

Circulating Fibroblast Growth Factor-21 and Risk of Metachronous Colorectal Adenoma

PURPOSE

Prior work has shown that higher circulating concentrations of fibroblast growth factor-21 (FGF-21) are associated with an increased likelihood of developing colorectal cancer. We conducted a prospective study to assess the relationship between circulating FGF-21 and odds of developing early neoplastic lesions in the colorectum.

METHODS

A total of 94 study participants were included from the ursodeoxycholic acid (UDCA) trial, a phase III, randomized, double-blind, placebo-controlled clinical trial of the effect of 8-10 mg/kg of body weight UDCA vs. placebo. Logistic regression analyses were conducted to evaluate the association between baseline FGF-21 concentrations and odds of developing a metachronous adenoma.

RESULTS

Of the characteristics compared across tertiles of FGF-21 concentrations, including age, race, sex, BMI, and other variables, only a previous personal history of colorectal polyps prior to entry into the UDCA trial was statistically significantly related to FGF-21 levels, with a proportion of 26.7%, 56.7%, and 50.0% across the first, second, and third tertiles, respectively (p < 0.05). Higher circulating concentrations of FGF-21 were statistically significantly associated with greater odds of developing a metachronous colorectal adenoma. After adjusting for potential confounders and when compared with the lowest tertile of FGF-21, the adjusted ORs (95% CIs) for metachronous colorectal adenoma in the second and third tertiles were 4.72 (95% CI, 1.42-15.72) and 3.82 (95% CI, 1.15-12.68), respectively (p trend < 0.05).

CONCLUSION

Our results reveal for the first time that, in addition to a recently discovered association with colorectal cancer, circulating FGF-21 concentrations are significantly and directly associated with odds of developing metachronous colorectal adenoma.

Imputation methods for addressing missing data in short-term monitoring of air pollutants

Monitoring of environmental contaminants is a critical part of exposure sciences research and public health practice. Missing data are often encountered when performing short-term monitoring (<24 h) of air pollutants with real-time monitors, especially in resource-limited areas. Approaches for handling consecutive periods of missing and incomplete data in this context remain unclear. Our aim is to evaluate existing imputation methods for handling missing data for real-time monitors operating for short durations. In a current field-study, realtime PM2.5 monitors were placed outside of 20 households and ran for 24-hours. Missing data was simulated in these households at four consecutive periods of missingness (20%, 40%, 60%, 80%). Univariate (Mean, Median, Last Observation Carried Forward, Kalman Filter, Random, Markov) and multivariate time-series (Predictive Mean Matching, Row Mean Method) methods were used to impute missing concentrations, and performance was evaluated using five error metrics (Absolute Bias, Percent Absolute Error in Means, R2 Coefficient of Determination, Root Mean Square Error, Mean Absolute Error). Univariate methods of Markov, random, and mean imputations were the best performing methods that yielded 24-hour mean concentrations with the lowest error and highest R2 values across all levels of missingness. When evaluating error metrics minute-by-minute, Kalman filters, median, and Markov methods performed well at low levels of missingness (20-40%). However, at higher levels of missingness (60-80%), Markov, random, median, and mean imputation performed best on average. Multivariate methods were the worst performing imputation methods across all levels of missingness. Imputation using univariate methods may provide a reasonable solution to addressing missing data for short-term monitoring of air pollutants, especially in resource-limited areas. Further efforts are needed to evaluate imputation methods that are generalizable across a diverse range of study environments.

Abstract D109: Helicobacter pylori infections in Navajo communities of Northern Arizona

Background: Helicobacter pylori (Hp) is a gastric pathogen associated with development of duodenal or stomach ulcers, stomach cancer, and mucosa associated lymphoid-tissue (MALT) lymphomas. While Hp prevalence is declining in many regions, it remains the leading infectious cause of cancer worldwide. In the United States prevalence varies by geographic location, ethnic background, socioeconomic status, and age. This pilot project seeks to understand the role of Hp infection in the development of stomach cancer among Native Americans of Northern Arizona, where stomach cancer incidence rates are approximately three times higher than the general Arizona population and it is the leading cause of cancer mortality. Methods: A cross-sectional survey based on a random sample of households selected using census block vectors for tribal lands overlaid onto satellite imagery. Potential household structures were marked and randomly sorted with recruitment goals set to be proportional to underlying population size. Houses were ‘ground-truthed’ for eligibility and residents approached for participation. A total of 72 households were recruited between June-August 2018 with 105 self-identified Navajo &gt;18 years old living in three communities in northern Arizona participating. Participants were assessed on household and individual level factors associated with infection. A urea breath test (UBT) was performed to test for active infection. We used logistic regression, adjusted for household clustering, to calculate odds ratios (aOR) and 95% confidence intervals (CI) for associations between UBT results and individual and household factors. Results: Active Hp infection was found in 66 of the 101 participants with valid UBT, crude prevalence of 65.4%. Male participants were more likely to be positive (aOR=2.89, 95% CI, 1.03-8.09). Participants with an unregulated household water source had the highest odds for positive UBT (aOR=8.85, 95% CI, 1.50-53.38). There was no association with age or education and a modest association with history of gallbladder disease. Only 23.8% reported they had ever heard of Hp infections and 12.9% previously tested for the infection. Conclusion: Prevalence of Hp is high among individuals in these Navajo communities. Use of household water that was not regulated, was strongly associated with active Hp infection. Further work is needed to determine if there is geographic variation and what Hp substrains are involved for this population. Attention also needs to focus on developing strategies to reduce the infection and target earlier detection.

Citation Format: Robin B Harris, Rachel Begay, Priscilla R Sanderson, Carmenlita Chief, Fernando Monroy, Heidi E Brown, Eyal Oren. Helicobacter pylori infections in Navajo communities of Northern Arizona [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 D109.

Effects of HIV status on non-metastatic cervical cancer progression among patients in Lusaka, Zambia

INTRODUCTION

Sub-Saharan Africa has the highest global incidence of cervical cancer. Cervical cancer is the most common cause of cancer morbidity and mortality among women in Zambia. HIV increases the risk for cervical cancer and with a national Zambian adult HIV prevalence of 16%, it is important to investigate the impact of HIV on the progression of cervical cancer. We measured differences in cervical cancer progression between HIV-positive and HIV-negative patients in Zambia.

METHODS

This study included 577 stage I and II cervical cancer patients seen between January 2008 and December 2012 at the Cancer Diseases Hospital in Lusaka, Zambia. The inclusion criteria for records during the study period included known HIV status and FIGO stage I and II cervical cancer at initial date of registration in the Cancer Diseases Hospital. Medical records were abstracted for clinical and epidemiological data. Cancer databases were linked to the national HIV database to assess HIV status among cervical cancer patients. Logistic regression examined the association between HIV and progression, which was defined as metastatic or residual tumor after 3 months of initial treatment.

RESULTS

A total of 2451 cervical cancer cases were identified, and after exclusion criteria were performed the final analysis population totaled 537 patients with stage I and II cervical cancer with known HIV status (224 HIV-positive and 313 HIV-negative). HIV-positive women were, on average, 10 years younger than HIV-negative women who had a median age of 42, ranging between 25 and 72. A total of 416 (77.5%) patients received external beam radiation, and only 249 (46.4%) patients received the recommended treatment of chemotherapy, external beam radiation, and brachytherapy. Most patients were stage II (85.7%) and had squamous cell carcinoma (74.7%). HIV-positive patients were more likely to receive lower doses of external beam radiation than HIV-negative patients (47% vs 37%; P<0.05, respectively). The median total dose of external beam radiation for HIV-positive and HIV-negative patients was 46 Gy and 50 Gy, respectively. HIV positivity did not lead to tumor progression (25.4% in HIV-positive vs 23.9% in HIV-negative, OR 1.04, 95% CI [0.57, 1.92]). However, among a subset of HIV-positive patients, longer duration of infection was associated with lower odds of progression.

CONCLUSION

There was no significant impact on non-metastatic cervical cancer progression by HIV status among patients in Lusaka, Zambia. The high prevalence of HIV among cervical cancer patients suggest that HIV-positive patients should be a primary target group for HPV vaccinations, screening, and early detection.

A Case-Control Study to Identify Community Venues Associated with Genetically-clustered, Multidrug-resistant Tuberculosis Disease in Lima, Peru

BACKGROUND

The majority of tuberculosis transmission occurs in community settings. Our primary aim in this study was to assess the association between exposure to community venues and multidrug-resistant (MDR) tuberculosis. Our secondary aim was to describe the social networks of MDR tuberculosis cases and controls.

METHODS

We recruited laboratory-confirmed MDR tuberculosis cases and community controls that were matched on age and sex. Whole-genome sequencing was used to identify genetically clustered cases. Venue tracing interviews (nonblinded) were conducted to enumerate community venues frequented by participants. Logistic regression was used to assess the association between MDR tuberculosis and person-time spent in community venues. A location-based social network was constructed, with respondents connected if they reported frequenting the same venue, and an exponential random graph model (ERGM) was fitted to model the network.

RESULTS

We enrolled 59 cases and 65 controls. Participants reported 729 unique venues. The mean number of venues reported was similar in both groups (P = .92). Person-time in healthcare venues (adjusted odds ratio [aOR] = 1.67, P = .01), schools (aOR = 1.53, P < .01), and transportation venues (aOR = 1.25, P = .03) was associated with MDR tuberculosis. Healthcare venues, markets, cinemas, and transportation venues were commonly shared among clustered cases. The ERGM indicated significant community segregation between cases and controls. Case networks were more densely connected.

CONCLUSIONS

Exposure to healthcare venues, schools, and transportation venues was associated with MDR tuberculosis. Intervention across the segregated network of case venues may be necessary to effectively stem transmission.

Ethnic Disparities in Gastric Cancer Presentation and Screening Practice in the United States: Analysis of 1997-2010 Surveillance, Epidemiology, and End Results-Medicare Data

BACKGROUND

Chronic infection with Helicobacter pylori (H. pylori) is the strongest risk factor for distal gastric cancer. Although gastric cancer incidence has decreased, variation by race and ethnicity is observed. This study describes gastric cancer presentation and screening services among Medicare patients by race/ethnicity, place of birth, and history of gastric cancer-related conditions.

METHODS

Using demographic, location, and disease staging information, extracted from the Surveillance, Epidemiology and End Results-Medicare gastric cancer database (1997-2010), we compared frequencies of gastric cancer-related conditions (e.g., peptic ulcer, gastric ulcer, gastritis) and screening (H. pylori testing and endoscopy) from inpatient and outpatient services claims by selected race/ethnicity and place of birth.

RESULTS

Data included 47,994 incident gastric cancer cases with Medicare claims. The majority (48.0%) of Asian/Pacific Islanders (API) were foreign-born, compared with non-Hispanic whites (NHW), Hispanics, and blacks (with 64.4%, 33.9%, and 72.9% U.S.-born, respectively). For NHWs, the most frequently diagnosed gastric cancer site was the cardia (35.6%) compared with <15% (P < 0.001) for APIs, Hispanics, and blacks. Although more than 57% of all cases had a history of gastric cancer-related conditions, H. pylori testing was reported in only 11.6% of those cases. H. pylori testing was highest for APIs (22.8%) and lowest for blacks (6.5%).

CONCLUSIONS

Noncardia gastric cancer, associated with H. pylori infection, was diagnosed more frequently among APIs, blacks, and Hispanics than NHWs. Testing for H. pylori was low among all gastric cancer cases despite evidence of risk factors for which screening is recommended. Studies are needed to increase appropriate testing for H. pylori among higher risk populations.

IMPACT

This study sheds light on poor screening practices despite presence of gastric cancer-related conditions.

Economic impact of epilepsy and the cost of nonadherence to antiepileptic drugs in older Medicare beneficiaries

Epilepsy is most prevalent among older individuals, and its economic impact is substantial. The development of economic burden estimates that account for known confounders, and using percent incremental costs may provide meaningful comparison across time and different health systems. The first objective of the current study was to estimate the percent incremental healthcare costs and the odds ratio (OR) for inpatient utilization for older Medicare beneficiaries with epilepsy and without epilepsy. The second objective was to estimate the percent incremental healthcare costs and the OR for inpatient utilization associated with antiepileptic drug (AED) nonadherence among Medicare beneficiaries with epilepsy. The OR of inpatient utilization for cases compared with controls (i.e., non-cases) were 2.4 (95% CI 2.3 to 2.6, p-value<0.0001) for prevalent epilepsy and 3.6 (95% CI 3.2 to 4.0, p-value<0.0001) for incident epilepsy. With respect to total health care costs, prevalent cases incurred 61.8% (95% CI 56.6 to 67.1%, p-value<0.0001) higher costs than controls while incident cases incurred 71.2% (95% CI 63.2 to 79.5%, p-value <0.0001) higher costs than controls. The nonadherence rates were 33.6 and 32.9% for prevalent and incident cases, respectively. Compared to nonadherent cases, the OR of inpatient utilization for adherent prevalent cases was 0.66 (95% CI 0.55 to 0.81, p-value <0.0001). The cost saving for a prevalent case adherent to AEDs was 13.2% (95% CI 6.6 to 19.4%, p-value=0.0001) compared to a nonadherent case. An incident case adherent to AEDs spent 16.4% (95% CI 6.5 to 25.2%, p-value=0.002) less than a nonadherent incident case on health care. Epilepsy is associated with higher health care costs and utilization. Older Medicare beneficiaries with epilepsy incur higher total health care spending and have higher inpatient utilization than those without epilepsy. Total health care spending is less for older Medicare beneficiaries who have prevalent or incident epilepsy if they are adherent to AEDs.

Ethnic Disparities in Gastric Cancer Presentation and Screening Practice in the United States: An Analysis of 1997–2010 SEER-Medicare Data

Describe differences in Helicobacter pylori (H. pylori) screening among a Surveillance, Epidemiology and End Results (SEER)-Medicare elderly population by ethnicity, place of birth, and gastric cancer (GC)-related conditions, as chronic infection with H. pylori is the strongest risk factor for distal GC. Methods: We used the National Cancer Institute's population-based SEER-Medicare cancer database for GC (1997–2010). We extracted demographic, location and disease staging information from the SEER data file, Patient Entitlement and Diagnosis Summary File. We obtained information on frequencies of various GC-related conditions (e.g., peptic ulcer, gastric ulcer, gastritis) and screening (H. pylori testing and endoscopy) from inpatient hospital and physician/outpatient services claims. Results: Data from 34,730 subjects were analyzed. The majority of Asian American/Pacific Islanders (AAPIs), 65.1%, were foreign-born, while majority of Non-Hispanic Whites (NHW), Hispanics and Blacks were US-born (88.7%, 51.3%, and 96.9%, respectively). NHWs were oldest at diagnosis (74.7 y.); Hispanic and Black cases were the youngest (72.4 and 72.9 y., respectively). For NHWs, the most frequently diagnosed GC site was the cardia (36.1%), while for AAPIs, Hispanics and Blacks, the most diagnosed sites were non-cardia (&gt;80%, P &lt; 0.001). Over 55% of NHW, Hispanic and Black cases were diagnosed at regional or distant stage, while 55% of AAPIs were diagnosed at local or regional stage. Over 57% of all cases had a history of GC-related conditions (AAPIs were highest at 64.1%). However, only 11.2% of total cases showed evidence of H. pylori testing. H. pylori testing was more frequent for foreign-born than US-born (2-fold increase in proportions) and AAPIs exhibited the highest proportion of H. pylori testing (22.6% among those with a GC-related condition). Conclusions: Screening for H. pylori was low for all GC cases, despite race/ethnic groups exhibiting conditions for which H. pylori testing is recommended. AAPI GC cases had the highest frequency of H. pylori testing with tumors staged locally or regionally; increased testing could lead to earlier stage of tumor at diagnosis. Future studies should investigate why screening rates are low in patients with GC-related conditions.

Nutrients in one-carbon metabolism and urinary arsenic methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004

Exposure to inorganic arsenic (inAs), a potent toxicant, occurs primarily through ingestion of food and water. The efficiency with which it is methylated to mono and dimethyl arsenicals (MMA and DMA) affects toxicity. Folate, vitamins B12 and B6 are required for 1C metabolism, and studies have found that higher levels of these nutrients increase methylation capacity and are associated with protection against adverse health effects from inAs, especially in undernourished populations. Our aim was to determine whether 1C-related nutrients are associated with greater inAs methylation capacity in a general population sample with overall adequate nutrition and low levels of As exposure. Univariate and multivariable regression models were used to evaluate the relationship of dietary and blood nutrients to urinary As methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Outcome variables were the percent of the sum of inAs and methylated As species (inAs+MMA+DMA) excreted as inAs, MMA, and DMA, and the ratio of MMA:DMA. In univariate models, dietary folate, vitamin B6 and protein intake were associated with lower urinary inAs% and greater DMA% in adults (≥18years), with similar trends in children (6-18). In adjusted models, vitamin B6 intake (p=0.011) and RBC folate (p=0.036) were associated with lower inAs%, while dietary vitamin B12 was associated with higher inAs% (p=0.002) and lower DMA% (p=0.030). Total plasma homocysteine was associated with higher MMA% (p=0.004) and lower DMA% (p=0.003), but not with inAs%; other blood nutrients showed no association with urinary As. Although effect size is small, these findings suggest that 1C nutrients can influence inAs methylation and potentially play an indirect role in reducing toxicity in a general population sample.

Nutrients in one-carbon metabolism and urinary arsenic methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004

Exposure to inorganic arsenic (inAs), a potent toxicant, occurs primarily through ingestion of food and water. The efficiency with which it is methylated to mono and dimethyl arsenicals (MMA and DMA) affects toxicity. Folate, vitamins B12 and B6 are required for 1C metabolism, and studies have found that higher levels of these nutrients increase methylation capacity and are associated with protection against adverse health effects from inAs, especially in undernourished populations. Our aim was to determine whether 1C-related nutrients are associated with greater inAs methylation capacity in a general population sample with overall adequate nutrition and low levels of As exposure. Univariate and multivariable regression models were used to evaluate the relationship of dietary and blood nutrients to urinary As methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Outcome variables were the percent of the sum of inAs and methylated As species (inAs+MMA+DMA) excreted as inAs, MMA, and DMA, and the ratio of MMA:DMA. In univariate models, dietary folate, vitamin B6 and protein intake were associated with lower urinary inAs% and greater DMA% in adults (≥18years), with similar trends in children (6-18). In adjusted models, vitamin B6 intake (p=0.011) and RBC folate (p=0.036) were associated with lower inAs%, while dietary vitamin B12 was associated with higher inAs% (p=0.002) and lower DMA% (p=0.030). Total plasma homocysteine was associated with higher MMA% (p=0.004) and lower DMA% (p=0.003), but not with inAs%; other blood nutrients showed no association with urinary As. Although effect size is small, these findings suggest that 1C nutrients can influence inAs methylation and potentially play an indirect role in reducing toxicity in a general population sample.