Immigrant Experience & Breast Cancer Risk in Asians

Institution: Cancer Prevention Institute of California
Investigator(s): Scarlett  Gomez , PhD -
Award Cycle: 2011 (Cycle 17) Grant #: 17UB-8602 Award: $705,771
Award Type: SRI Request for Proposal (RFP)
Research Priorities
Community Impact of Breast Cancer>Disparities: eliminating the unequal burden of breast cancer



Initial Award Abstract (2011)

Non-technical overview of the research topic and relevance to breast cancer: High and rapidly increasing incidence rates of breast cancer among California Asian Americans (AA) have been masked by rates reported for AAs as a single group. Not only do rates vary considerably among AA ethnic groups, we recently showed that they are high among young US-born women, rapidly increasing among some US-born and foreign-born groups, and in some cases, are even higher than among non-Hispanic white women. With these dynamic incidence patterns, we have an unparalleled opportunity for better understanding the critical windows of exposure for risk factors like diet and weight gain, and for identifying new risk factors, including infectious exposures, family and community influences, and social stressors related to the process of immigration, being an immigrant, and to discrimination.

Research question(s) or central hypotheses: We propose to 1) document the extent to which new and established risk factors among AAs vary across over the lifespan and are affected by family and community influences; 2) explore new hypotheses relating to the impact of immigrant exposures across the lifespan on breast cancer risk, and 3) compile pilot data on effective strategies for recruiting AAs for future studies. This study will efficiently leverage our ongoing work with AA breast cancer cases being recruited as part of a currently funded cancer survivorship study called “Equality in Breast Cancer Care” (EBCC). This application also proposes to incorporate existing data on community-level measures from our California Neighborhoods Data System, to relate community factors to individual-level risk factors and breast cancer risk.

General methodology: AA breast cancer cases (N~350), ages 20 or over at diagnosis, and residing in the Bay Area, will be recruited as part of the EBCC study, through the population-based regional cancer registry, and much of their exposure data will be obtained through the EBCC telephone interviews. A second interview will collect the additional information needed for the currently proposed study. Controls (N~700), or women in the general population at risk for breast cancer, will be recruited using one of four methods: 1) an approach based on address directories; 2) the California Cancer Detection Program; 3) the Army of Women; and 4) various community-based approaches. We expect these methods to be considerably more efficient than prior approaches in recruiting AA controls, and pooled together, will result in a representative sample.

Innovative elements: Considerable resources have been devoted to understanding the causes of breast cancer; however, to date, our knowledge of this disease still remains limited. Research in immigrant populations has helped to identify many of the established risk factors for breast cancer. Using a trans-disciplinary approach and integrating prior work and expertise in epidemiology, sociology, anthropology, and community interests, we will be asking new questions, as well as looking at some old questions in more detailed and nuanced ways. Applying this approach to a population with widely varying and unique histories, cultures, and lifestyles, coupled with their dynamic breast cancer rates, this study has the potential to reverse the rapidly increasing incidence rate of breast cancer among many of the AA groups in California, as well as provide valuable insights regarding the etiology of breast cancer that can be targeted towards all women for reducing their risk of breast cancer. An additional innovative element is the evaluation of novel methods for recruiting controls, particularly as traditional methods are increasingly costly and biased.

Advocacy involvement and relevance to the human issues associated with breast cancer: The diversity and unique cultures, particularly across generations, of the AA population present exceptional opportunities for identifying causes and understanding the reasons for the wide variation in breast cancer incidence that we have previously documented. However, most of the prior research has not fully capitalized on the unique aspects of AA history, culture, lifestyles, contextual exposures, etc., that may provide valuable insights into breast cancer etiology. Working in partnership with the Asian Pacific Islander American Health Forum, community input will be central to the design, execution, and dissemination of results from this project. This project addresses a disease that has long been thought not to be a problem in the AA community. Extending our considerable prior work to explore, in more detail, the specific aspects relating to the process and consequences of immigration on breast cancer risk, we will provide valuable data that can start to be used to inform AA women about reducing their own risk of breast cancer.




Progress Report 2 (2014)

We and others have shown that breast cancer rates are high among young US-born women, rapidly increasing among some US-born and foreign-born groups, and in some cases, are even higher than among non-Hispanic white women in California. We propose to (1) document the extent to which new and established risk factors among Asians/Pacific Islanders (API) vary across over the lifespan and are affected by family and community influences; (2) explore new hypotheses relating to the impact of immigrant exposures across the lifespan on breast cancer risk, and (3) compile pilot data on effective strategies for recruiting APIs for future population-based studies. This study will efficiently leverage our ongoing work with API breast cancer cases (N=199) recruited as part of a cancer survivorship study called “Equality in Breast Cancer Care” (EBCC). This current application also proposes to incorporate existing data on community-level measures from our California Neighborhoods Data System (CNDS), to explore the relationships among individual-level risk factors, community context, and breast cancer risk.

We have completed data collection since the last reporting period and have begun data analysis towards the specific aims. Of 204 Asian and Pacific Islander (API) breast cancer patients who had participated in the Equality in Breast Cancer Care (EBCC) study and who agreed to be re-contacted by our study team for future research, 2 were deceased and 6 were lost to follow-up and untraceable. Of the remaining 197, 56 have refused (includes “passive” refusals) (28.4%), 139 (70.6%) have completed an interview, and 1 was ineligible (moved back to Hong Kong) (0.50%). Of the 139 who have completed an interview, 73 (52.5%) are Chinese, 31 (22.3%) are Filipina, 13 (9.3%) are Japanese, 12 (8.6%) are South Asian, and the remainder (N=10, 7.2%) other API.

With regards to controls, we distributed the control recruitment across the following sources: address-based mailings, community health centers (Asian Health Services (AHS) and Asian Americans for Community Involvement (AACI)), Army of Women (AOW), Asian and Pacific Islander American Health Forum (APIAHF), and Craigslist/Facebook/Twitter/ “Other” (friends/family, outreach at race-specific events, etc). The distributions of controls across these sources were based on assumptions about the sociodemographics of APIs recruited from each of these sources; however, we are assessing on a monthly basis the representativeness of the recruited controls with the source population, based on data from the California Health Interview Survey (CHIS), and adjusting the relative proportions from the recruitment sources accordingly. We interviewed and/or received a mailed survey from a total of 488 controls, thus achieving a case:control ratio of 1:3.5.

As we have concluded the recruitment, we have begun the data analysis. The team, including community collaborators, are working together on operationalizing the key variables of interest. We have begun conducting the analysis and drafting a manuscript describing in detail the control recruitment methods above and assessment of representativeness. We anticipate that this manuscript will be completed and submitted to a peer-reviewed journal in early 2015. We have a requested a no-cost extension of 12 months; this additional time will allow us to complete the analyses, disseminate the findings, and plan for the next study.

Major accomplishments thus far include developing a protocol for identifying and recruitment API controls from a variety of sources; establishing stronger collaborations with AHS, AACI, and APIAHF; and developing a method for assessing representativeness of recruited controls. We have developed a process that can be scaled up for larger-scale recruitment of controls or population members. We also obtained pilot funding from the Stanford Cancer Institute to re-contact a small sample of cases and controls to test a method of capturing real-time data using smart phones and online surveys, a method called ecological momentary assessment (EMA). The data we have generated so far on these control recruitment and EMA methods were used as preliminary data for a recent R01 grant application on tobacco use among Asian American women.




Progress Report 3 (2015)

We recently showed that breast cancer rates are high among young US-born women, rapidly increasing among some US-born and foreign-born groups, and in some cases, are even higher than among non-Hispanic white women in California. We propose to (1) document the extent to which new and established risk factors among AAs vary across over the lifespan and are affected by family and community influences; (2) explore new hypotheses relating to the impact of immigrant exposures across the lifespan on breast cancer risk, and (3) compile pilot data on effective strategies for recruiting AAs for future population-based studies. This study will efficiently leverage our ongoing work with AA breast cancer cases (N=200) being recruited as part of a currently funded cancer survivorship study called “Equality in Breast Cancer Care” (EBCC). This current application also proposes to incorporate existing data on community-level measures from our California Neighborhoods Data System (CNDS), to explore the relationships among individual-level risk factors, community context, and breast cancer risk.

We have made considerable progress over the past reporting period, despite unforeseen circumstances. We have not yet completed the specific aims.

We encountered barriers related to two of our four proposed control recruitment methods: Cancer Detection Program and Army of Women. We were unable to use the Cancer Detection Program for identifying and recruiting controls, and so, with permission from the CBCRP, we identified alternative strategies to recruit medically underserved women via two Asian-serving community health centers, Asian Health Services (AHS) in Oakland and Asian Americans for Community Involvement (AACI) in San Jose. Our second barrier involved recruitment through Army of Women, but we were just recently informed that we will be able to use the Army of Women for our recruitment.

Major accomplishments thus far include refining the study protocol and developing a survey through working with collaborators at the Asian Pacific Islander American Health Forum (APIAHF), AHS, AACI, and consultants. We have developed a website (www.asianchi.org) and brochure, translated and back-translated all study materials, and received IRB approval. We have worked with a public directory company and received 3000 household addresses for targeted (likely Asian households) mailings.

We are poised to begin recontact of EBCC cases and recruitment of controls in January 2013. Our plans in the next reporting period are to conduct the recruitment and interviewing of 200 cases and 700 controls. We will also keep track of efficiencies in the various recruitment methods and representativeness of controls recruited through each method by comparing to Census 2010 and 2007-2011 American Community Survey data (which we have already requested).




Progress Report 4 (2016)

To begin to address the rapidly increasing rates of breast cancer among Asian American women, and to use the opportunity to explore novel risk factors, we conducted a pilot case-control study to: 1) Determine, among controls (representing women in the general population at risk for breast cancer), the associations between perceived stress and the immigration experience and discrimination, and how these associations are modified by generational status, timing of immigration, and coping styles; 2) Determine, among controls, how other relevant breast cancer exposures, including age-specific markers of infectious disease exposures, physical activity and body size, and dietary intake and behaviors, vary with generational status and timing of immigration; 3) Among controls, assess the extent to which the factors in Aims 1 and 2 vary according to family, social network, and neighborhood characteristics and relationships; and 4) Among cases and controls, identify the associations between the factors in Aims 1 and 2 and breast cancer risk among Asian American, Native Hawaiian, and Pacific Islander (AA & NHPI) women. Secondarily, we aimed to develop and test methods for recruitment of a representative sample of AA and NHPI controls.

We recruited 139 cases and 488 controls. Although these numbers were lower than we had originally aimed, we did succeed in our overall aims. A major barrier was difficulties in recruitment. Our study produced the following novel findings/major accomplishments:

• AA & NHPI women without breast cancer varied by ethnicity and immigration status in measures of social networks, neighborhood collective efficacy, active coping, perceived overall stress, immigration-related stress, changes in social standing with immigration, experiences with lifetime and everyday discrimination, and responses to discrimination.
• Higher stress among recent immigrants that was explained by language proficiency.
• Higher stress and less neighborhood collective efficacy was associated with less physical activity.
• Greater time in the U.S. was associated with higher body mass index across all periods in life.
• Neighborhood factors including collective efficacy, disorder, socioeconomic status, and ethnic enclave, as well as social networks, showed associations with body size and physical activity across the life course, and with early-life infectious context.
• We developed two indices of dietary acculturation – Asian and western, and found differences in these indices across individual and contextual factors.
• Greater early-life infectious exposures was associated with reduced breast cancer risk.
• It is feasible to use multiple approaches to recruit a representative sample of AA & NHPI controls (manuscript conditionally accepted at the Journal of Epidemiology and Community Health)
• Pilot data that have been used for other pilot studies and grant applications.

We plan to continue further analyses of the above study findings and plan to disseminate these findings through scientific manuscripts and presentations at conferences. We also plan to pursue funding for a larger study of breast cancer in AA & NHPI women, based on the findings and approaches from this pilot study.

Publications:
Strategies for recruiting representative samples of Asian Americans for a population-based case–control study