Knowledge, Attitudes, Beliefs, Practices Regarding Human Papillomavirus (HPV), and Barriers to Vaccination Against HPV Infection: A Cross-Sectional Survey of Guam Residents

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States and is linked to several cancers. In Guam, the HPV vaccination rate falls short of the National Healthy People 2030 goal. Only half of eligible Guam teens have received the HPV vaccination series. Additionally, research on Guam HPV vaccination is limited. A cross-sectional survey was conducted, and a representative sample of Guam residents (n=775) was surveyed to examine their knowledge, attitudes, beliefs, practices regarding HPV, and barriers to HPV vaccination. Aggregated scores were calculated for these scale items: attitude, knowledge, subjective norms, and perceived behavioral control regarding HPV. One-way Analysis of Variance (ANOVA) was used to compare the means of the scores and check for significant differences. Binary logistic regression helped to identify significant predictors of HPV vaccination among respondents with children. Significant differences were found for sex, education, income, and ethnicity. Women and those with higher education and income demonstrated higher positive attitudes and knowledge about HPV vaccination. Also, those with health insurance and those who were advised by their physician were more likely to get their children vaccinated. These results will guide the implementation of effective strategies for developing targeted behavioral and other appropriate interventions to increase HPV vaccination in Guam.

Disparities in Colorectal Cancer Incidence among Asian and Pacific Islander Populations in Guam, Hawai'i, and the United States

Colorectal cancer (CRC) ranks among the three most common cancers in Guam (GU), Hawai'i (HI), and the mainland United States (US). CRC prevalence in these areas is high among Filipinos, and indigenous CHamorus and Native Hawaiians; however, data on these populations are frequently aggregated in epidemiological studies, which can mask true CRC disparities. We examined CRC cumulative incidence rates (CIRs) among CHamorus in GU, Filipinos in GU, HI, and the US, and Native Hawaiians in HI and the US. CRC CIRs were calculated for two age groups (20-49 years; early onset, and 50-79 years; senior) and four time periods (2000-2004, 2005-2009, 2010-2014, and 2015-2019), stratified by ethnicity, sex, and location. Data analyzed included all invasive CRC cases reported to the Surveillance, Epidemiology, and End Results 9-Registry (n = 166,666), the Hawai'i Tumor Registry (n = 10,760), and the Guam Cancer Registry (n = 698) between 2000 and 2019. Senior CIRs were highest in HI and lowest in GU throughout all time periods, with a downward trend observed for senior CIRs in the US and HI, but not GU. This downward trend held true for all ethnic groups, except for CHamorus in GU, females in GU, and females of CHamoru ethnicity in GU. In contrast, early onset CIRs increased across all locations, sexes, and ethnic groups, except for Filipinos in HI and males of Filipino ethnicity in HI. Our findings provide crucial insights for future research and policy development aimed at reducing the burden of CRC among indigenous populations.

The Betel Nut Intervention Trial (BENIT)-A Randomized Clinical Trial for Areca Nut and Betel Quid Cessation: Primary Outcomes

BACKGROUND

Areca nut and betel quid (ANBQ) chewing is a widespread carcinogenic habit. The BENIT (ClinicalTrials-NCT02942745) is the first known randomized trial designed for ANBQ chewers.

METHODS

We compared the intensive behavioral treatment intervention condition (IC) with the control condition (CC) in the BENIT and included a 5-stage early stopping rule. We report the primary analysis at stage 3. English-literate adults in Guam and Saipan who self-identified as ANBQ chewers with tobacco were enrolled between August 2016 and August 2020. IC participants (n = 88) received five in-person sessions over 22 days and a brochure containing quitting advice. CC participants (n = 88) received only the brochure. Participants were assessed at baseline and on day 22 of follow-up. Self-reported chewing status at day 22 was determined by a composite of two survey items with disparate wording and response options for cross-verification.

RESULTS

Cessation rates were 38.6% (IC) and 9.1% (CC). Proportional hazards regression revealed a p = 0.0058, which met the Stage 3 criteria for significance, and an estimated reduction in ANBQ chewing for IC compared to the CC of 71% (95% CI: 41%-88%).

CONCLUSIONS

Robust self-reported intervention effects at day 22 suggest that intensive cessation programs such as BENIT should be further developed and implemented on a larger scale.

Abstract 6493: Ethnic disparities in breast cancer survival in Guam

Background: Breast cancer is the second leading cause of cancer-related death among women in Guam. The breast cancer mortality rate is higher in Guam than in the U.S. (27.3 vs 20.3 per 100,000 women, age-adjusted, 2013-2017 data); even though the incidence rate remains lower (86.6 vs 126.8 respectively). Guam has major ethnic disparities in breast cancer survival with CHamoru (indigenous people) and Micronesian (immigrants from other Micronesian Islands) faring much worse than other ethnic groups. The purpose of this study was to determine the survival rates of breast cancer patients in Guam and examine the effects of demographic and other mortality risk factors on breast cancer survival.

Methods: This study included 1105 women diagnosed with primary invasive breast cancer and reported to the Guam Cancer Registry from 1998-2020. Five-year and 10-year survival rates were calculated using the Kaplan-Meier method and were compared using the log-rank test across different ethnic groups: CHamoru (N = 528), Filipino (N = 336), Asian (N = 66), Micronesian (N = 51), and Caucasian (N = 71). The Cox proportional hazards regression was used to investigate the effects of age, year of diagnosis, ethnicity, breast cancer staging, and cancer treatment status on the risk of all-cause mortality.

Results: Mean age at diagnosis was 58.2 years. Significant differences in the 5-year and 10-year survival rates were found across ethnic groups. Micronesians had the lowest 5-year and 10-year survival rates (55.9% and 48.5%) followed by CHamorus (81.1% and 68.1%, respectively). All-cause mortality was higher among CHamoru (HR = 2.28, 95% CI: 1.65, 3.16) and Micronesian women (HR=5.33, 95% CI: 3.30, 8.61) compared with Filipino women after adjusting for age, year of diagnosis, staging, and cancer treatment status. All-cause mortality among White and Asian women was not statistically significantly different from that among Filipino women. Cancer staging also indicated significantly higher hazard rate for late-stage patients when compared to early-stage patients (HR = 3.62, 95% CI: 2.70, 4.85).

Conclusion: The analysis suggests significant differences in breast cancer 5-year and 10-year survival rates across different ethnic groups, with Micronesian women exhibiting the highest hazard rate among women in Guam.

Acknowledgement: This study was supported by the PIPCHE/U54 Grant (U54CA143728), a partnership between the University of Hawai'i Cancer Center and the University of Guam.

Citation Format: Grazyna Badowski, Rodney Teria, Louis Dulana, Cabrini Aguon, Lynne Wilkens, Yurii Shvetsov, Rachel Novotny, Rachael T. Leon Guerrero. Ethnic disparities in breast cancer survival in Guam. [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 6493.

Cervical Cancer and HPV Knowledge and Awareness: An Educational Intervention among College Students in Guam

BACKGROUND

Compared to the U.S. population, cervical cancer (CC) incidence is significantly higher among the CHamoru, Micronesian, and Caucasian populations in Guam. From 2008-2012, CC was the fifth most common cancer diagnosed on the island. Despite the prevalence of CC and low HPV vaccine uptake, there is a concerning lack of awareness and preventative behavior among young adults.  This study was aimed at influencing college students' knowledge and awareness of CC, CC screening, HPV, and the HPV vaccination.

METHODS

We delivered a 30-minute educational intervention to a sample of 108 university students in a classroom setting. The effect of the educational intervention was measured through a pre-and post-test on CC and HPV health behaviors, knowledge, and awareness. Results were analyzed using SPSS and an exact McNemar's test was used to examine the difference in the proportion of correct answers to the tests. Two-way mixed ANOVA was used to examine between (gender, ethnicity, and class level) and within subjects (pre-and post-test) program effects.

RESULTS

Of the 108 participants, only 39 (36.1%) reported being vaccinated for HPV, 23 (21.3%) had not been vaccinated, and 46 (42.6%) did not know if they had been vaccinated for HPV.  Only forty-one (60.3%) female participants had had a Pap smear. When comparing the pre-to-posttest responses, most questions had an increase in correct responses. Time also influenced CCA and HPV knowledge and awareness scores as there was a significant increase in scores from the pre- to post-test.

CONCLUSION

The educational intervention was an effective tool for increasing knowledge and awareness of CC, HPV, and HPV vaccination among college students. While study results demonstrate the educational intervention's success as a baseline measure of knowledge, the inclusion of behavioral outcome measures, such as intent to get vaccinated or screened, could result in more robust future studies.

Salivary Areca and tobacco alkaloids for bioverification in the Betel Nut Intervention Trial

BACKGROUND

The Betel Nut Intervention Trial (BENIT) is the first known randomized controlled intervention trial designed to help minority Pacific Islanders in Guam and Saipan quit chewing the carcinogenic Areca catechu nut (AN). We report the BENIT's saliva bioverification results against the self-reported chewing status ("quitter" or "chewer") at day 22 follow-up.

MATERIAL AND METHODS

AN-specific (arecoline, arecaidine, guvacoline, and guvacine) and tobacco-specific (nicotine, cotinine, and hydroxycotinine) alkaloids were analyzed in saliva from 176 BENIT participants by an established and sensitive liquid chromatography mass spectrometry-based assay.

RESULTS

The combined four AN alkaloid levels decreased from baseline in quitters (n = 50) and chewers (n = 108) by 32% and 9%, respectively. In quitters, decreases were significant for arecoline (p = 0.044)-the most prominent AN alkaloid, along with arecaidine (p = 0.042) and nicotine (p = 0.011). In chewers, decreases were significant only for hydroxycotinine (p = 0.004). Similar results were obtained when quitters and chewers were stratified by treatment arm.

DISCUSSION

Salivary AN alkaloid levels generally agreed with self-reported chewing status, which suggests the former can be used to verify the latter.

CONCLUSION

Our results can help to objectively evaluate compliance and program effectiveness in AN cessation programs.

Prediction of breast cancer risk among women of the Mariana Islands: the BRISK retrospective case-control study

OBJECTIVES

To develop a breast cancer risk prediction model for Chamorro and Filipino women of the Mariana Islands and compare its performance to that of the Breast Cancer Risk Assessment Tool (BCRAT).

DESIGN

Case-control study.

SETTING

Clinics/facilities and other community-based settings on Guam and Saipan (Northern Mariana Islands).

PARTICIPANTS

245 women (87 breast cancer cases and 158 controls) of Chamorro or Filipino ethnicity, age 25-80 years, with no prior history of cancer (other than skin cancer), residing on Guam or Saipan for at least 5 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Breast cancer risk models were constructed using combinations of exposures previously identified to affect breast cancer risk in this population, population breast cancer incidence rates and all-cause mortality rates for Guam.

RESULTS

Models using ethnic-specific relative risks performed better than those with relative risks estimated from all women. The model with the best performance among both ethnicities (the Breast Cancer Risk Model (BRISK) model; area under the receiver operating characteristic curve (AUC): 0.64 and 0.67 among Chamorros and Filipinos, respectively) included age at menarche, age at first live birth, number of relatives with breast cancer and waist circumference. The 10-year breast cancer risk predicted by the BRISK model was 1.28% for Chamorros and 0.89% for Filipinos. Performance of the BCRAT was modest among both Chamorros (AUC: 0.60) and Filipinos (AUC: 0.55), possibly due to incomplete information on BCRAT risk factors.

CONCLUSIONS

The ability to develop breast cancer risk models for Mariana Islands women is constrained by the small population size and limited availability of health services and data. Nonetheless, we have demonstrated that breast cancer risk prediction models with adequate discriminatory performance can be built for small populations such as in the Mariana Islands. Anthropometry, in particular waist circumference, was important for estimating breast cancer risk in this population.

Pacific Islands Cohort on Cardiometabolic Health Study: rationale and design

BACKGROUND

Pacific Islanders, including those residing in the US Affiliated Pacific Islands (USAPI), experience some of the highest mortality rates resulting from non-communicable diseases (NCDs) worldwide. The Pacific Island Health Officers' Association declared a Regional State of Health Emergency in 2010 due to the epidemic of NCDs in the USAPI. Obesity, a known risk factor for NCDs, has become an epidemic among both children and adults in Micronesia and other parts of the USAPI. There is some recent information about overweight and obesity (OWOB) among young children in the USAPI, but there is no data looking at the relationship between children and their biological parents. The Pacific Islands Cohort on Cardiometabolic Health (PICCAH) Study aims to collect data on NCD lifestyle factors from two generations of families (n = 600 child-parent dyads or 1,200 participants) living in Guam, Pohnpei, and Palau.

METHODS

The PICCAH Study is an epidemiological study using community-based convenience sampling to recruit participants in USAPI of Guam, Palau, and Pohnpei. The goal is to recruit participant dyads consisting of 1 child plus their biological parent in Guam (500 dyads or 1,000 participants), Pohnpei (50 dyads or 100 participants), and Palau (50 dyads or 100 participants). All participants are having the following information collected: demographic, health, and lifestyle information; anthropometry; diet; physical activity; sleep; acanthosis nigricans; blood pressure; and serum levels of fasting plasma glucose, fasting insulin, glycated hemoglobin, total cholesterol, triglycerides, LDL, and HDL.

DISCUSSION

The PICCAH Study is designed to establish the baseline of a generational epidemiologic cohort with an emphasis on cardiometabolic risk, and to better understand the extent of DM and CVD conditions and related risk factors of those living in the USAPI jurisdictions of Guam, Pohnpei, and Palau. This study also serves to further build research capacity in the underserved USAPI Region.

Technical note: Low clinical efficacy, but good acceptability of a point-of-care electronic palpation device for breast cancer screening for a lower middle-income environment

BACKGROUND

Late-stage breast cancer rates in the Pacific where mammography services are limited are exceedingly high: Marshall Islands (61%), Palau (94%), and Samoa (79%). Due to the limited medical resources in these areas an alternative accessible technology is needed. The iBreast Exam (iBE) is a point-of-care electronic palpitation device that has a reported sensitivity of 86%. However, little is known about the performance and acceptability of this device for women in the Pacific.

METHODS

A total of 39 women (ages 42-73 years) were recruited in Guam with 19 women having a mammogram requiring biopsy (Breast Imaging-Reporting and Data System [BI-RADS] category 4 or above) and 20 women with a negative screening mammogram before the study visit. Participants received an iBE exam and completed a 26-item breast health questionnaire to evaluate the iBE. Furthermore, the performance characteristics of the iBE were tested using gelatin breast phantoms in terms of tumor size, tumor depth, and overall breast stiffness.

RESULTS

The iBE had a sensitivity of 20% (two true positives to eight false negatives) and specificity of 92% (24 false positives to 278 true negatives) when analyzed based on the location of the tumor by quadrant. The iBE also had generally poor agreement according to a Cohen's kappa value of 0.068. The phantom experiments showed that the iBE can detect tumors as deep as 2.5 cm, but only if the lesion is greater than 8 mm in diameter. However, the iBE did demonstrate acceptability; 67% of the women reported that they had high trust in iBE as an early detection device.

CONCLUSIONS

The iBE had generally poor sensitivity and specificity when tested in a clinical setting which does not allow its use as a screening tool.

IMPACT

This study demonstrates the need for an alternative screening method other than electronic palpation for lower-middle-income areas.

Abstract PO-068: Cervical cancer and HPV knowledge and awareness: An educational intervention among college students in Guam

The incidence of cervical cancer (CCA) in Guam, a U.S. territory in the Western Pacific, is six times higher among Micronesians and over three times higher for CHamorus (Guam's indigenous people) and Caucasians living in Guam than the U.S. population. Educational interventions among college students who can still get the HPV vaccine, particularly among women below and about the age for initial CCA screening, is crucial. Our team designed and delivered a 20-30 minute presentation to college students in a classroom setting. Pre- and post-tests measured changes in knowledge and attitudes about CCA. Summary variables were computed for CCA and HPV Knowledge and Awareness. McNemar's test was used to compare knowledge and attitudes before and after the presentation. A total of 108 students completed the survey. Most participants were female (63.0%), juniors (44.4%), and identified as either CHamoru (36.1%) or Filipino (26.9%). A majority had a regular source of healthcare (77.8%), a primary physician (56.5%), and private health insurance (52.8%). Results show male and female students had similar pre- and posttest scores. Among ethnic groups, Caucasians had the highest pretest scores and non-CHamoru Pacific Islanders had the lowest. All ethnic groups had statistically significant increases in CCA Knowledge and Awareness scores after the presentation. Three individual one-way ANOVAs with gender, ethnicity and class level as the factors were performed using the different total scores of the CCA and HPV Knowledge and Awareness as the dependent variables. There was no significant difference interaction between gender (F=0.498, p=0.482), class level (F=0.371, p=0.774), or ethnicity (F=0.398, p=0.810). However, the results showed a significant main effect of Time on CCA Knowledge and Awareness (p<0.001). There was a significant increase for all independent variables in CCA and HPV Knowledge and Awareness from pre- to post-test. The McNemar test shows that there are significant positive differences in the proportion of correct responses to most of the questions between the pre- and posttest. The percentage of correct answers to questions related to symptoms and causes of CCA, the increased risk caused by HPV, and the prevention of CCA through routine screening was already high at pretest so the difference was not significant. Overall, study participants perceived the presentation an effective tool to educate individuals about CCA. Before the presentation, 63.9% rated their general knowledge about CC as neutral or unknowledgeable. After the presentation, this decreased to 11.1%. This type of educational intervention for CCA is critical for this age group, since most can still get the HPV vaccine and women are at the age of initial CCA screening. This study shows that the college setting is an appropriate venue to increase CCA and HPV awareness and potentially impact HPV vaccination for females. Future studies should test presentation paired with opportunities for HPV vaccination via college or public health services.

Citation Format: Lilnabeth P. Somera, Tressa P. Diaz, Angelina Mummert, Jaeyung Choi, Kristian Ayson, Grazyna Badowski. Cervical cancer and HPV knowledge and awareness: An educational intervention among college students in Guam [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-068.

Improving Willingness to Try Fruits and Vegetables and Gross Motor Skills in Preschool Children in Guam

Early childhood interventions have the potential to promote long-term healthy eating and physical activity habits to prevent obesity. However, research studies including indigenous young children are lacking. This study examined the effectiveness of the Food Friends^®: Fun with New Foods™ and Get Movin’ with Mighty Moves™ (FFMM) curricula on willingness to try fruits and vegetables (FV) and gross motor (GM) skills among preschoolers in Guam. A pre-post community-based study included preschoolers from Head Start (HS), gifted and talented education (Pre-GATE), and Pre-Kindergarten programs during school years (SY) 2017–2018 and 2018–2019. In SY2017–2018, the intervention group had a significant increase in imported FV when compared with the other three groups. No significant differences between groups were found on the other FV scales. Regarding gross motor skills, no significant differences between groups were found. In SY2018–2019, the intervention group had a significant increase in all FV scales except imported FV when compared with the enhanced intervention group. With gross motor skills, no significant differences were found between groups on its progress. These results warrant FFMM adaptations for the prevention of obesity among Guam preschoolers.

Development and evaluation of an undergraduate curriculum on non-communicable disease research in Guam: The Pacific Islands Cohort of College Students (PICCS)

Background

The non-communicable disease (NCD) epidemic among Pacific Islanders prompted the declaration of a regional state of NCD emergency throughout the United States-Affiliated Pacific Islands (USAPIs) in 2010. Subsequently, the University of Guam Health Science Program launched a pilot study on NCD research in its undergraduate curriculum modeled after the Pacific Data for Decision Making (DDM) framework – a field epidemiology training program employed in the USAPIs. The primary objective of the research is to conduct annual assessments of student health indicators with plans for longitudinal follow-up. Here, development and evaluation of the undergraduate research curriculum are described.

Methods

The Pacific DDM framework covering knowledge and skills in resourcing, types of data and indicators, data sources, data management, information products, and data dissemination and use were incorporated in undergraduate core courses of the Health Science Program. During the data collection pilot years, 2013 and 2014, a survey containing questions predominantly on NCD risk factors was launched at the university. The survey was administered by upperclassmen in the Health Science Program and evolved into the Pacific Islands Cohort of College Students (PICCS) research study. The initial years were spent developing the infrastructure. Program outputs were tracked annually to measure program success.

Results

Students in the Health Science Program obtained research knowledge and skills through various courses while enrolled in the program. The PICCS data collection continued annually as a cross-sectional survey from 2015 to current. Numerous successes have resulted including student abstracts and publications, acceptances to summer programs and fellowships, a sustained annual health fair for college students, a grant award, and other program-related impacts.

Conclusion

The PICCS framework provided the organizational structure and documented tools, protocols, roles, and responsibilities to enhance consistency and reproducibility. Undergraduate students applied their knowledge and skills to an ongoing study focused on NCD risk factor surveillance of college students. Additionally, multiple research successes have been achieved through the PICCS curriculum. Plans are underway to begin the longitudinal design of the PICCS research study and sustain it through the curriculum, with room for adaptation as courses are updated over time.

The Association of Cardiometabolic Risk Factors in Parent-Child Dyads in Guam: PICCAH Study

Objectives

To determine metabolic syndrome (MetS) prevalence among adults and children at-risk in Guam as part of the larger Pacific Island's Cohort for Cardiometabolic Health (PICCAH) study during 2017–2020. Embedded in the primary objective is to evaluate the associations of parent and child risk factors and identify prevalent modifiable risk factors in children.

Methods

Preliminary data from 338 adults (21–50 y) and 214 children (3–9 y) who completed lifestyle surveys, anthropometric and (fasting) biochemical measures were analyzed. The prevalence of MetS and MetS risk factors were calculated for adults and children, respectively, and MetS severity Z-scores for both.  Pearson correlation and multiple linear regression was used to estimate the linear association between parent and child MetS Z-scores. Demographic data and metabolic lifestyle factors such as sleep, sedentary and physical activity, and stress were evaluated.

Results

The majority of adults (92.3%) had abdominal obesity. Metabolic factors in adults and children (respectively) were high serum triglycerides (18.5% and 2.7%) and high glucose (25% and 1.8%) and, in adults only, were high blood pressure (31.8%) and low level of HDL (60.4%). Adults and children in this study did not meet sleep (57.3% and 50.0%), screen time for children (83.8%), sedentary activity (e.g., time spent sitting) for adults (61.9%), and physical activity for adults (52.4%) recommendations. Adults reported low-level stress (Mean = 19.3, SD = 5.7 on 12–48 scale) on the Depression Anxiety Stress Scale (DASS21). Using the International Diabetes Federation criteria, 38.7% of adults had MetS and 8.2% children were at-risk for MetS. Children MetS Z-scores were significantly correlated with parent MetS Z-scores (Pearson correlation = 0.288, P < 0.001).  The multiple regression model showed that child MetS Z-score can be predicted by using parent MetS Z-score even after adjusting for parent education level and income, and child's age (F(4190) = 4.82, P = .001).

Conclusions

Guam is an island in the Western Pacific with the highest diabetes prevalence in the world. This is the first study in Guam to describe MetS and its risk factors in child-parent dyads. Findings will support intervention programs for MetS and diabetes prevention in Guam and the Western Pacific.

Funding Sources

NIH/NIMHD (1U24MD011201–01).

Abstract PO-070: Knowledge, attitudes, beliefs, practices regarding human papillomavirus (HPV), and barriers to vaccination against HPV infection: A cross-sectional survey of Guam residents

Background Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States and is linked to cervical, anal, vaginal, vulvar, penile, and oropharyngeal cancers. In the U.S. territory of Guam, the incidence of cervical cancer is six times higher in Micronesians and over three times higher for CHamorus than the U.S. population. Though nasopharyngeal cancer has other contributing factors beyond HPV infection such as smoking and drinking, the CHamorus, who are the Indigenous people of Guam, have an incidence rate of nasopharyngeal cancer 20 times that of the U.S. population. In Guam, HPV vaccination rate is sub-optimally short of the National Healthy People 2020 goal to have at least 80% of females and males between the ages 13-15 years complete the HPV vaccine series. In 2016, 55.8% females and 33.2% males completed the HPV vaccination. Objective Our study sought to analyze a representative sample of Guam residents to examine their knowledge, attitudes, beliefs, practices regarding HPV, and barriers to HPV vaccination. Methods The cross-sectional survey of 776 respondents included 38% males and 62% females. The three major ethnic groups in the sample were CHamoru (48%), Filipino (26%), and Micronesians (11%). Sixty-eight percent of the respondents had at least one child. The aggregated scores were calculated for the following scale items: attitude (A), knowledge (K), subjective norms (SN), and perceived behavioral control (PBC) regarding HPV. Results Almost 45% of respondents admitted that they do not have enough knowledge to have their children vaccinated. However, 88% of those respondents stated that they would have their children vaccinated if the doctor told them. Women had significantly higher mean scores than men for A, K, and PBC/SN. Participants with more than high school education and higher incomes have significantly higher mean scores for all three measures. There were significant differences among different ethnic groups, with Micronesians having the lowest average score for all three measures. There were no significant differences between participants who had their children vaccinated and those who did not. Only 48% of respondents with children reported having their children vaccinated. Only ethnicity and having insurance were significant predictors of HPV vaccination. The respondents with medical insurance were almost three times as likely to have their children vaccinated for HPV (OR=2.8; 95% CI: 1.4, 5.2) Conclusions The results highlighted the significance of the physician’s role in having the HPV vaccination. Our results will serve as a guide to implement effective strategies for the development of targeted behavioral interventions and to develop appropriate interventions to increase the HPV vaccination uptake on Guam.

Citation Format: Ana Joy Mendez, Lilnabeth Somera, Grazyna Badowski, Angelina Mummert, Lucy Castro, Angrenilda Antolin. Knowledge, attitudes, beliefs, practices regarding human papillomavirus (HPV), and barriers to vaccination against HPV infection: A cross-sectional survey of Guam residents [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-070.

Acculturation and Cancer Risk Behaviors among Pacific Islanders in Hawaii

Background

To communicate research to the public, the National Cancer Institute developed the Health Information National Trends Survey (HINTS). However, as with most national health surveillance, including the Behavioral Risk Factor Surveillance System, HINTS data are not sufficient to address unique demographic subpopulations such as US Pacific Islanders (PIs). National sampling methods do not adequately reach participants from small, medically underserved populations.

Aim

This study aims to document the cancer-relevant knowledge, attitudes, behaviors, and information-seeking practices of PIs in Hawaii (HI).

Methods

We conducted a cross-sectional survey during 2017-2018 of Native Hawaiians, Chuukese, and Marshallese in HI using Respondent Driven Sampling (RDS) to recruit these geographically diffuse groups. The modified HINTS survey included questions about cancer knowledge, attitudes and behaviors, health communications, and cultural practices.

Results

A total of 515 Native Hawaiians, 305 Chuukese, and 180 Marshallese completed the survey. Differences were found across a variety of cancer-related attitudes, knowledge, and behaviors. These groups also differed regarding acculturation, health locus of control, and trust in medical professionals. Native Hawaiians were significantly more acculturated (P=.0001) than Chuukese or Marshallese and more likely to smoke cigarettes (P=.0001). Among participants aged >50 years, we found no significant differences across ethnic groups (P=.30) for those completing a colon cancer screening (37%). However, only 27% were referred to screening by a physician.

Conclusions

Cancer prevention programs are greatly needed for PIs in HI. This study provides knowledge concerning the efficiency of RDS to recruit participants, and the role of culture in communications influencing cancer risk behaviors, which may be generalizable to migrant PIs in the United States.

Abstract 1190: Comparison of cumulative incidence rates of colorectal cancer among Asians and Pacific Islanders (API) populations in Guam, Hawai'i, and the United States

Background: Colorectal cancer is one of 4 most common cancers on Guam, Hawai'i (HI) and the US. However, incidence rates vary between ethnic groups and location.

Objective: The objective of the study was to compare cumulative incidence rates (CIRs) among ethnic groups in Guam, HI, and the US; specifically, Chamorros in Guam, Filipinos in Guam, HI and the US, and Native Hawaiians in HI and the US. CIRs are weighted sums of age-specific incidence rates therefore they can be used for comparisons between populations. They are relatively stable and thus provide a good estimate of cumulative risk of cancer.

Methods: This study included all colorectal cancer cases (n=562) reported to the Guam Cancer Registry and all colorectal cancer cases (n=253,782) reported to the Surveillance, Epidemiology, and End Results (SEER) 9-Registry from 2000 to 2014. Cumulative incidence rates were calculated for three time periods: 2000-2004, 2005-2009, and 2010-2014 and compared by age, ethnicity and location.

Results: Differences were seen in CIRs by time-period, age, ethnicity, and location. For all three time periods: 2000-2004, 2005-2009, 2010-2014, the lifetime cumulative incidence rates (age 0-79) were highest for Hawai'i (5.7%, 5.4%, and 5.3% respectively), followed by the US (5.2%, 4.5%, and 3.7%) and Guam (4.3%, 3.3%, and 3.6%). Interestingly, there were large differences in lifetime CIRs between Filipinos in HI, Filipinos in the US and Filipinos on Guam (i.e. 6.5%, 3.7%, and 2.4% respectively in 2005-2009). The Chamorros on Guam had the rate at least 1.5 times higher than Filipinos on Guam (4.3 % vs 3.3%) and close to the rate of Native Hawaiians in HI (4.9%). Overall, there was downward trend for the lifetime CIRs over time. Only for the Filipinos in HI, the rates went up. However, early onset CIRs (age 0-49) went up across all locations and ethnic groups.

Conclusions: Disparities in colorectal cancer incidence were identified. Further study is needed to examine how exposure to risk factors and screening changes with immigration and how this variation contributes to the incidence disparities.

Citation Format: Grazyna Badowski. Comparison of cumulative incidence rates of colorectal cancer among Asians and Pacific Islanders (API) populations in Guam, Hawai'i, and the United States [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1190.

Cumulative Incidence Rates of Breast Cancer by Age for Filipinos and Chamorros in Guam

Breast cancer is the second leading cause of cancer-related death among women on Guam and Hawai'i. Breast cancer incidence rates are described here for the multiethnic population in Guam, a United States (US) Pacific island territory, and compared to Hawai'i and other US populations, to understand the risk by age and race/ethnic group in this understudied group. The study included all breast cancer cases (n=576) reported to the Guam Cancer Registry, all breast cancer cases (n=8345) reported to the Hawai'i Tumor Registry and all breast cancer cases (n=678,637) reported to the Surveillance, Epidemiology, and End Results program from 2000 to 2009. Cumulative incidence rates by age were calculated for two time periods: 2000-2004 and 2005-2009. Differences were seen in cumulative incidence rates by age, ethnicity, and place of residence. Cumulative incidence rates by age 40 were the highest (0.7%) among Filipinos in Guam but, after age 40, the rates for Chamorros (indigenous Pacific Islanders of Guam) increased rapidly. The lifetime cumulative incidence rates were the highest for Chamorros in Guam (15.3%), close to the US rate (15.5%). Results were similar for 2005-2009. Women in Guam are at high risk for breast cancer, with the indigenous Chamorros having the highest risk, and the most prevalent Asian group of Filipinos, having a younger age at diagnosis. These patterns are similar to the comparable Pacific Islander and Filipino populations in Hawai'i and the US generally.

Abstract C015: Social network analysis with respondent driven sampling data: A study of ethnic and geographic integration on Guam and Hawaii

US Pacific Islanders are one of the fastest-growing population groups in the US, and serious disparities in health outcomes exist in this group, with cancer being the leading cause of death. Limited knowledge about the cancer communication practices and risk behaviors of US Pacific Islanders, as well as their social network structure and integration, makes effective cancer prevention interventions difficult, and contributes to disparities. In 2017, we conducted a survey on health communication on Guam and Hawaii using the respondent-driven sampling method (RDS) to recruit participants (N=733 for Hawaii, and N=533 for Guam). RDS is a network-based sampling technique where initial seed respondents recruit others from their social networks. The recruiting process repeats iteratively, thereby forming long referral chains. RDS provides a viable data for making inferences about the underlying network structure. During the sampling process two pieces of information are gathered. First, each recruiter-recruit dyad is documented. Second, respondents are asked how many other members of the target population they know and interact with. In this study, we used this information to create recruitment chains and test the quantity and quality of cross-gender, cross-ethnicity, cross-generation ties. We also analyzed the geographic distribution and spatial clustering of the samples. Self-reported network size (degree) was used to estimate of a homophily, a measure of the strength of association to one's own group beyond random mixing. In general, strong homophily was found for different ethnic groups (with values ranging from 0.7 to 0.8), whereas gender and age had weak homophily. Even though the participants tended to recruit spatially proximal peers, both samples in Guam and Hawaii eventually covered the whole catchment area.

Citation Format: Grazyna Badowski, Louis Dulana, Lilnabeth P. Somera, Kevin Cassel, Hye-ryeon Lee, Janessa Roman, Jayson Morales. Social network analysis with respondent driven sampling data: A study of ethnic and geographic integration on Guam and Hawaii [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 C015.

Cultural Considerations for Conducting the Health Information National Trends Survey with Micronesian Communities: Lessons from a Qualitative Study

A critical barrier to addressing health disparities among minorities is the lack of data, particularly on Pacific Islanders. Typically, national health surveillance systems do not have the resources to ensure proper representation of these small population groups. This study reports factors that guided the cultural adaptation and administration of the National Cancer Institute's Health Information Trends National Survey (HINTS) for a United States-dwelling Pacific Islander population in Hawai'i. To adapt the survey, four focus groups were conducted with 32 purposively-selected Micronesian migrants. Themes on health, healthcare barriers, cancer and methods to implement the survey were extracted from the analyses of the focus group narratives. Key cultural factors were identified that impact health practices, including religious and cancer fatalism, racism, health locus of control and other barriers. Using information from the focus group participants, the HINTS questionnaire was modified and the survey was implemented. The survey data provided will inform the future delivery of health promotion strategies for this unique medically underserved population.

Abstract C074: Areca (betel) nut chewing and metabolic conditions

Oral cancer is the most widely studied health outcome linked to areca (betel) nut chewing, or mastication of the Areca catechu fruit or seed often combined with slaked lime, tobacco, and the Piper betle (leaf). A growing area of research is the influence of betel nut chewing on metabolic conditions. To investigate betel nut chewing and metabolic conditions, including obesity and related health characteristics, a cross-sectional study of 122 adults was conducted in Guam between July 2013 and October 2014. Information on demographics, medical history, dietary intake and betel nut use was collected. Height and weight measurements were collected to calculate body mass index or BMI (weight in kg/height in m2) as an indicator of weight status. Waist was also measured to calculate waist-to-height ratio as an indicator of health risk status. Health characteristics were compared across the three chewing groups: 64 current betel nut chewers, 37 former betel nut chewers, and 21 non-betel nut chewers. Strong evidence of differences by betel nut exposure were seen by ethnicity (predominantly Chamorros across all chewing groups), BMI (predominantly obese among former betel nut chewers), waist-to-height ratio (predominantly high risk among current and former betel nut chewers), history of self-reported stroke (predominant among former betel nut chewers), and alcohol consumption (highest number of drinks among current betel nut chewers). The evidence of poor metabolic conditions seen among current betel nut chewers supports the need for a comprehensive approach to betel nut prevention strategies, to include the prevention of oral cancer and metabolic conditions. The evidence of poor metabolic conditions seen among former betel nut chewers warrants additional advanced study designs to rule out temporal ambiguity, and to further investigate any health implications of betel nut cessation.

Citation Format: Yvette C. Paulino, Alisha N. Yamanaka, Patrick F.P. Sotto, Grazyna Badowski, Lynne R. Wilkens, Brenda Y. Hernandez. Areca (betel) nut chewing and metabolic conditions [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 C074.

Abstract C098: Correlates of cervical cancer screening among Pacific Islander women on Guam and Hawaii

Background There are significant disparities in cervical cancer incidence and mortality rates among Pacific Islander women. Native Hawaiian females have the highest incidence rates for cervical cancer in HI, and Chamorro and Micronesian have the highest incidence rates on Guam. The objective of this study was to examine the rates and the correlates of Pap smear test among Pacific Islander women. Methods This study conducted a cross-sectional survey using respondent driven sampling (RDS) of 802 women aged 21-65, including 235 Native Hawaiians, 190 Chuukese, 119 Marshallese, 157 Chamorro and 62 Filipino from Guam and Hawaii. Self-reported screening rates were compared across ethnic groups and migrant status using chi-square and Fisher’s exact tests. Binary logistic regression was used to identify significant predictors of cervical cancer screening. Results Only 64% of our sample had received a screening for cervical cancer within the past 3 years. Filipino women had the highest screening rates (71%) followed by Chamorro (69%), Marshallese (68%), Native Hawaiian (64%) and Chuukese (58%). There was no significant difference in screening rates between women aged 21-39 and 40-65. Recent migrants were less likely to have been screen within the past 3 years when compared to US born respondents (OR=0.37; 95% CI: 0.16, 0.84) even after adjusting for education and having health care. Those women agreeing with the statement that health systems treat people unfairly based on their ethnic background were less likely to be screen (OR=0.52; 95% CI: 0.31, 0.81) when compared with those who did not agree. Conclusion The rates for cervical cancer screening tests for Pacific Island women remain far below the goals set forth in Healthy People 2010. Culturally competent, community-based care for women is needed to increase Pap smear screening among minority groups

Citation Format: Grazyna Badowski, Louis Dulana, Lilnabeth P Somera, Kevin Cassel, Hye-ryeon Lee. Correlates of cervical cancer screening among Pacific Islander women on Guam and Hawaii [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 C098.

Rationale and design of a randomized, controlled, superiority trial on areca nut/betel quid cessation: The Betel Nut Intervention Trial (BENIT)

Background

Areca nut (AN) is the seed endosperm of the Areca catechu L. palm and a Group 1 carcinogen chewed by 10–20% of the world population. AN is often chewed with Piper betle L. leaf, slaked lime, and tobacco to form a betel quid (BQ). The negative health effects associated with AN/BQ consumption warrant the need for an evidence-based cessation program. However, systematic research on AN/BQ cessation is rare.

Methods/design

The Betel Nut Intervention Trial (BENIT; trial #NCT02942745) is a randomized controlled trial designed to test the efficacy of an intensive AN/BQ cessation program. The trial is ongoing in Guam and Saipan with adult chewers who include tobacco in their BQ. Enrolled participants are assessed for their primary (chewing status) and secondary (saliva bio-verification) outcome at baseline, 22 days, and 6 months. Participants randomized into the control arm receive an educational booklet while those randomized into the intervention arm receive the educational booklet and a 22-day cessation program modeled after a smoking cessation program and led by trained facilitators. Information on chewing behavior (history, reasons for chewing, and AN/BQ composition and dependency) are collected. The intervention effectiveness is assessed using the logistic mixed model to compare cessation status between randomization groups.

Discussion

AN/BQ chewing affects a large population of people, many of whom live in low and moderate income countries in the Asia-Pacific region. Although the BENIT focuses on chewers in Guam and Saipan, it has the potential for greater regional and global importance.

Culture, Communication, and Cancer Risk Behaviors Among Pacific Islanders in Hawaii

Background: A priority of the National Cancer Institute (NCI) is to acquire, aggregate and integrate cancer control data that facilitates collaborations to address health disparities and communication inequalities. To better communicate cancer research to the public, the NCI developed the Health Information National Trends Survey (HINTS). However, as with most national health surveillance systems, HINTS nationally obtained data are not sufficient to address the behaviors of unique demographic and geographic subpopulations. US Pacific Islanders are one of the fastest growing population groups in the US, and cancer is the leading cause of death in this group. Limited knowledge about the cancer communication practices and risk behaviors of US Pacific Islanders drive the poor implementation of effective cancer prevention interventions. Aim: This study aims to document the prevalence and differences in the cancer relevant knowledge, attitudes, and information seeking practices of Pacific Islander populations residing in Hawaii. Specifically, we aim to expand HINTS assessment to native Hawaiians and recent migrant Marshallese and Chuukese populations in Hawaii. Methods: We conducted surveys with 352 native Hawaiians, 282 Chuukese, and 129 Marshallese residing in HI. We used Respondent Driven Sampling method (RDS) to recruit these geographically diffuse populations in HI. The survey included questions about basic knowledge, attitude and behavior about various cancers, detailed communication behaviors about health information, and cultural beliefs and practices. Results: Data show there are clear differences among the three ethnic groups across a variety of cancer-related attitudes, knowledge, behaviors and risk factors. For example, a larger proportion of Chuukese have BMIs that can be described as obese or morbidly obese compared with native Hawaiians. On the other hand, native Hawaiians are significantly more likely to smoke than Marshallese and Chuukese. These groups also differ significantly regarding the level of acculturation, religiosity, fatalism about cancer, and trust in medical professionals. Regarding communication, cell phone use was common with 75% of native Hawaiians, 80% of Marshallese and 88% of Chuukese having cell phones. This use of cellphone technology was in stark contrast to Internet use with only 45% of native Hawaiians, 49% of Marshallese and 27% of Chuukese reporting access to the Web. Conclusion: There is a need for cancer prevention programs for Pacific Islanders in Hawaii. An effective health program has to address their unique cultural beliefs and practices, and fit their unique communication ecology. This study provides new knowledge concerning the use of nonprobability based study sampling methods, and the role of culture in cancer-related communications in influencing cancer risk behaviors that may be generalizable to the growing number of migrant Pacific Islander populations living in the US.

Abstract 5278: Tobacco and areca nut use among Chuukese youth in Guam

Background: Little is known regarding the tobacco use of Micronesian population in Guam. According to the Youth Risk Behavior Survey (YRBS) 2013, Micronesian youth have a higher prevalence rate of current smokers (27.2% vs. 15.7% for U.S.) and current smokeless tobacco users (39.7% vs. 8.8% for US) compared to the U.S. They also have the highest rate among all ethnic groups in Guam. This study aims to investigate tobacco use and areca nut use, which may explain high lung and bronchus cancer incidence and mortality rates among Micronesians. The survey in this study focuses on Chuukese youth, the largest group among Micronesians in Guam.

Methods: Respondent-driven sampling method (RDS) was used to recruit 364 Chuukese youth (ages 13-19) to complete the survey. YRBS question items that measured cigarette, cigar, and smokeless tobacco use were included in the survey. Measures for areca nut use were also included. Chi-square tests were performed by bivariate analysis. Only high school-level youth are included in the analysis.

Results: A total of 237 Chuukese high school students completed the survey. Fourteen percent of the participants currently smoke cigarettes, 6.4% currently smoke cigars, and 23.7% currently use smokeless tobacco. In addition, smokeless tobacco remains highest regarding daily use (11%) within the past 30 days prior the survey. Although there is high use of smokeless tobacco among participants, there are significant associations between gender and cigarette and gender and cigar use only. Boys smoke cigarettes and cigar at higher rates than girls. Among the recruited participants, 32% are areca nut users with tobacco product as an ingredient. There is significantly high association between smokeless tobacco users and areca nut with tobacco users. The majority of cigarette smokers (82.4%) have tried to quit smoking. Fifty-six percent of the smokeless tobacco users have tried to quit as well. However, only 17% of the participants are aware of the Guam Youth Quitline.

Conclusion: Results suggest the need to raise awareness among Chuukese youth on tobacco cessation programs on Guam, particularly the smoking cessation quitline. Tobacco cessation efforts should not focus on cigarette use only, but must also be expanded to include the use of smokeless tobacco products and chewing areca nut. Future studies should investigate the roles and implications of tobacco as an ingredient of areca nut chewing among Micronesian youth.

Citation Format: Lilnabeth P. Somera, Brayan Simsiman, Grazyna Badowski, Hye-ryeon Lee, Kevin Cassel. Tobacco and areca nut use among Chuukese youth in Guam [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5278.

Risk factors for breast cancer in the breast cancer risk model study of Guam and Saipan

BACKGROUND

Chamorro Pacific Islanders in the Mariana Islands have breast cancer incidence rates similar to, but mortality rates higher than, those of U.S. women. As breast cancer risk factors of women of the Mariana Islands may be unique because of ethnic and cultural differences, we studied established and suspected risk factors for breast cancer in this unstudied population.

METHODS

From 2010-2013, we conducted retrospective case-control study of female breast cancer (104 cases and 185 controls) among women in the Mariana Islands. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each of various lifestyle-related factors from logistic regression of breast cancer, in all women and in pre- and postmenopausal women separately. Tests for interaction of risk factors with ethnicity were based on the Wald statistics for cross-product terms.

RESULTS

Of the medical and reproductive factors considered - age at menarche, breastfeeding, number of live births, age at first live birth, hormone use, and menopause - only age at first live birth was confirmed. Age at first live birth, among parous women, was higher among cases (mean 24.9 years) than controls (mean 23.2 years); with increased breast cancer risk (OR=2.53; 95% CI, 1.04-6.19 for age≥30y compared to <20y, P for trend=0.01). Of the lifestyle factors -body mass index, waist circumference, physical activity, alcohol and betel-nut intake, and education - only waist circumference (OR=1.65; 95% CI 0.87-3.14 for the highest tertile group compared to the lowest, P for trend=0.04) was significantly associated with breast cancer risk and only in Filipino women. The association with many other established risk factors, such as BMI, hormone use and physical activity, were in the expected direction but were not significant. Associations for family history of breast cancer and alcohol intake were not evident CONCLUSIONS: The results provide a basis for cancer prevention guidance for women in the Mariana Islands.

The efficacy of respondent-driven sampling for the health assessment of minority populations

BACKGROUND

Respondent driven sampling (RDS) is a relatively new network sampling technique typically employed for hard-to-reach populations. Like snowball sampling, initial respondents or "seeds" recruit additional respondents from their network of friends. Under certain assumptions, the method promises to produce a sample independent from the biases that may have been introduced by the non-random choice of "seeds." We conducted a survey on health communication in Guam's general population using the RDS method, the first survey that has utilized this methodology in Guam. It was conducted in hopes of identifying a cost-efficient non-probability sampling strategy that could generate reasonable population estimates for both minority and general populations.

METHODS

RDS data was collected in Guam in 2013 (n=511) and population estimates were compared with 2012 BRFSS data (n=2031) and the 2010 census data. The estimates were calculated using the unweighted RDS sample and the weighted sample using RDS inference methods and compared with known population characteristics.

RESULTS

The sample size was reached in 23days, providing evidence that the RDS method is a viable, cost-effective data collection method, which can provide reasonable population estimates. However, the results also suggest that the RDS inference methods used to reduce bias, based on self-reported estimates of network sizes, may not always work. Caution is needed when interpreting RDS study findings.

CONCLUSIONS

For a more diverse sample, data collection should not be conducted in just one location. Fewer questions about network estimates should be asked, and more careful consideration should be given to the kind of incentives offered to participants.

Discrete-time singularly perturbed Markov chains: aggregation, occupation measures, and switching diffusion limit

This work is devoted to asymptotic properties of singularly perturbed Markov chains in discrete time. The motivation stems from applications in discrete-time control and optimization problems, manufacturing and production planning, stochastic networks, and communication systems, in which finite-state Markov chains are used to model large-scale and complex systems. To reduce the complexity of the underlying system, the states in each recurrent class are aggregated into a single state. Although the aggregated process may not be Markovian, its continuous-time interpolation converges to a continuous-time Markov chain whose generator is a function determined by the invariant measures of the recurrent states. Sequences of occupation measures are defined. A mean square estimate on a sequence of unscaled occupation measures is obtained. Furthermore, it is proved that a suitably scaled sequence of occupation measures converges to a switching diffusion.

Health Information Seeking, Source Trust, and Culture: A Comparative Analysis of Health Information Trends and Needs Between Guam and the United States

The Guam population offers a unique glimpse into Americans of Pacific Island ancestry and their communication and information-seeking behaviors, experiences, and needs relevant to cancer. National surveys do not typically include the U.S. territories, so there are limited data on the health and cancer information-seeking behaviors of these populations, in which health disparities persist. To fill this information gap, we conducted a survey on health communication in Guam using a modified version of the Health Information National Trends Survey instrument supplemented with items measuring specific cultural factors and communication practices. The results of the survey (N = 511) revealed some differences in health and cancer information-seeking patterns in Guam and the mainland United States. Sociodemographic variables, including sex, age, education, income, and employment, were significantly associated with health and cancer information seeking and Internet use. Levels of trust in various information sources were differentiated in the Guam and mainland U.S.

SAMPLES

Logistic regression models revealed differences in factors predicting health and cancer information seeking and Internet use. The results suggest that these health information-seeking patterns and factors should be taken into account when developing communication strategies for more effective prevention and control programs.

Abstract 3702: Cumulative incidence rates of breast cancer for Filipinos and Chamorros in Guam and the United States

Background

Breast cancer is the leading cause of cancer-related death among women on Guam. However incidence rates vary between Chamorros and Filipinos, the two predominant ethnic groups on Guam.

Objective

Our objective was to compare age-specific cumulative incidence rates among ethnic groups in Guam and US. Cumulative incidence rates are relatively stable and thus provide a good estimate of cumulative risk of breast cancer.

Methods

This study included all breast cancer cases (n = 576) reported to the Guam Cancer Registry from 2000 to 2009 and all breast cancer cases (n = 678,637) reported to the Surveillance, Epidemiology,and End Results (SEER) 18-Registry Database. Cumulative incidence rates were calculated for Filipinos and Chamorros for two time periods: 2000-2004 and 2005-2009. For comparison, cumulative incidence rates were also calculated for all women in Guam and the US, and for Filipino only in the US.

Results

Remarkable differences were seen in cumulative incidence rates by age and ethnicity. During the 2000-2004 time period, the cumulative incidence rates by age 40 in Filipinos on Guam were the highest (0.7%) and almost threefold higher than the rate in Chamorros (0.24%). But after age 40, the rates for Chamorros increased rapidly. The lifetime cumulative incidence rates (age 0-75) for Chamorros was highest in Guam (11.4%) and close to the US rate (12%). Interestingly, there was a marked difference in lifetime cumulative incidence rates between Filipino women in Guam and Filipinos in the US (7% and 10.9% respectively). Similar results were found for the 2005-2009 time period.

Conclusions

The observed disparity among ethnic groups suggests ethnic differences in exposure or response to certain risk factors. Further study is needed to examine possible differences in risk behaviors between Filipinos and Chamorros in Guam, as well as between Filipinos in Guam and Filipinos in the US.

Citation Format: Grazyna Badowski, Rachael Leon Guerrero, Brayan Simsiman, Rachel Novotny, Lynne Wilkens. Cumulative incidence rates of breast cancer for Filipinos and Chamorros in Guam and the United States. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3702. doi:10.1158/1538-7445.AM2015-3702

Relative validity and reliability of a quantitative food frequency questionnaire for adults in Guam

Background

Guam is a US territory in the western Pacific with a diverse population that includes understudied ethnic groups such as Chamorros and Filipinos. A food frequency questionnaire (FFQ) to estimate dietary intake was needed to facilitate studies of diet and health among adults living in Guam.

Objective

To develop and validate an FFQ to assess dietary intake over a 1-year period among adult Guam residents.

Design

A three-part study was conducted: 1) an initial cross-sectional study using 24-h recalls to identify a food and beverage list for the FFQ and resulting in a final FFQ containing 142 food and drink items; 2) to test reliability, 56 different individuals completed the FFQ twice; and 3) to test relative validity, self-administered FFQs and up to 2 days of food record data from an additional 109 individuals were collected, and daily nutrient intake from the two methods was compared.

Results

The reliability of the FFQ was very good (ρ range=0.65–0.75), and the relative validity of the FFQ was good for women (median Spearman's correlation [ρ] between instruments of 0.45 across 20 nutrients and an interquartile range [IQR] of 0.42–0.58) and generally adequate for men (median ρ=0.31, IQR=0.23–0.55). Validity was also good for Chamorros (median ρ=0.47, IQR=0.38–0.53) and generally adequate for Filipinos (median ρ=0.42, IQR=0.20–0.62). Correlations after energy adjustment were lower (overall median ρ=0.20, IQR=0.14–0.26).

Conclusions

The FFQ can be used to rank nutrient intake for adults in Guam and may be helpful in the analysis of relationships between diet and chronic disease in Guam.

Screening for oral potentially malignant disorders among areca (betel) nut chewers in Guam and Saipan

BACKGROUND

The Mariana Islands, including Guam and Saipan, are home to many ethnic subpopulations of Micronesia. Oral cancer incidence rates vary among subpopulations, and areca (betel) nut chewing, a habit with carcinogenic risks, is common. Our objectives were to conduct a screening program to detect oral potentially malignant disorders (OPMD) in betel nut chewers, measure their betel nut chewing practices, and assess the prevalence of the oral human papillomavirus (HPV) infection in a subset of betel nut chewers in these islands.

METHODS

A cross-section of 300 betel nut chewers ≥18 years old [in Guam (n = 137) and in Saipan (n = 163)] were recruited between January 2011-June 2012. We collected demographic, socioeconomic, and oral behavioural characteristics. Latent class analysis was used to identify chewing patterns from selected chewing behaviours. Following calibration of OPMD against an expert, a registered oral hygienist conducted oral examinations by house to house visits and referred positive cases to the study dentist for a second oral examination. Buccal smears were collected from a subset (n = 123) for HPV testing.

RESULTS

Two classes of betel nut chewers were identified on 7 betel nut behaviours, smoking, and alcohol use; a key difference between the two Classes was the addition of ingredients to the betel quid among those in Class 2. When compared on other characteristics, Class 1 chewers were older, had been chewing for more years, and chewed fewer nuts per day although chewing episodes lasted longer than Class 2 chewers. More Class 1 chewers visited the dentist regularly than Class 2 chewers. Of the 300 participants, 46 (15.3%; 3.8% for Class 1 and 19.4% for Class 2) had OPMD and one (0.3%) was confirmed to have squamous cell carcinoma. The prevalence of oral HPV was 5.7% (7/123), although none were high-risk types.

CONCLUSIONS

We found two patterns of betel nut chewing behaviour; Class 2 had a higher frequency of OPMD. Additional epidemiologic research is needed to examine the relationship between pattern of chewing behaviours and oral cancer incidence. Based on risk stratification, oral screening in Guam and Saipan can be targeted to Class 2 chewers.

Cancer mortality following polychlorinated biphenyl (PCB) contamination of a Guam village

Beginning more than 10 years after the release of polychlorinated biphenyl (PCB) contamination in the favored fishing grounds of Merizo village, an increase in the proportional cancer mortality rate was observed among residents of the village. This increased rate continued for approximately 20 years after which it returned to near island-wide Guam levels. Although the temporal association between PCB contamination of the environment of this village and an increase in cancer mortality is intriguing, it does not necessarily demonstrate a cause and effect relationship.

OBJECTIVE

To investigate a possible temporal relationship between PCB contamination of the Cocos Lagoon and cancer deaths in the adjoining village of Merizo.

METHODS

Data utilized in the study included deaths recorded by the Guam Cancer Registry (years 2000 to 2007) and data collected from original death certificates (years 1968-1999). To check whether there was a significant difference in the proportion of deaths due to cancer in Merizo compared with the rest of Guam, deaths were grouped in four 10-year periods, 1968-1977, 1978-1987, 1988-1997, and 1998-2007, and the Pearson Chi-Square test was calculated for each period separately

RESULTS

While the number of new cancer cases recorded in the village of Merizo were insufficient in number to draw a statistically significant conclusion when single year incidence rates were compared to the rest of the island, a proportional mortality study showed a distinct increase for the village of Merizo compared to other villages for the period 1978-1997.

CONCLUSION

While it is not possible to conclude with certainty that PCB contamination of the Cocos Lagoon was responsible for the observed increase in the proportion of cancer deaths in Merizo village beginning during the 10-year period 1978-1987, that increase and the subsequent decrease as PCB levels also decreased presents the possibility that these trends may be related.