The Influence of Neighborhoods on Breast Cancer Risk and Survivorship

The Cancer Prevention Institute of California recently led three studies examining the role of neighborhood social and structural factors on breast cancer risk and survivorship.

FREMONT, CA (April 6, 2017) — Neighborhood residential surroundings, specifically the social and man-made “built” environments, impact health outcomes by providing the local context for health behaviors and well-being. Only a few studies have been able to examine the role of neighborhoods in cancer development and survivorship while accounting for participants’ risk factors.  

The Cancer Prevention Institute of California (CPIC) recently led three studies published in the Cancer Epidemiology Biomarkers & Prevention April focus issue on Geospatial Approaches to Cancer Control and Population Sciences. All three studies examined neighborhood environments in relation to breast cancer, the most common cancer among women. The studies used U.S. Census and other environmental data from the California Neighborhoods Data System, a resource established by researchers at CPIC. The characterization of local environments included neighborhood socioeconomic status and aspects that may impact walkability/physical activity (e.g., street connectivity, traffic density, number of businesses, parks, and recreational facilities) and diet (e.g., unhealthy food outlets). By focusing exclusively on these specific neighborhood characteristics, these studies identified relationships between the neighborhood environment and breast cancer risk and survivorship, pointing to the importance of local resources and structure in impacting individuals’ health. 

In the first study, for the first time, researchers evaluated the impact of the neighborhood factors that promote weight gain and obesity with risk of postmenopausal breast cancer. They found that living in certain types of neighborhoods, including those of higher socioeconomic status, more urban, and less mixed-land development, placed residents at higher risk for breast cancer. However, these patterns differed for racial/ethnic groups. Specific results include:  
  • Women living in the lowest socioeconomic neighborhoods had a 21 percent lower risk of breast cancer than women living in the highest SES neighborhoods, particularly among Latinas.  
  • Breast cancer risk was lower for Japanese women living in more urban environments. 
  • Breast cancer risk was 10 percent higher for women living in neighborhoods with more unhealthy food outlets. 
  • Breast cancer risk was higher for Latinas living in neighborhoods with lower mixed-land development.
The study included 48,247 postmenopausal African American, Japanese, Latino and white women who participated in the California component of the Multiethnic Cohort, a population-based, prospective study of risk factors for cancer and other chronic diseases.  Women resided predominately in Los Angeles County. Over a 17-year-period, 2,341 women were diagnosed with breast cancer.

This work was supported by National Cancer Institute grant R01 CA154644. The Multiethnic Cohort was supported by National Cancer Institute grant U01 CA164973. The development of the California Neighborhoods Data System was supported by National Cancer Institute grant R03 CA117324 and by a Rapid Response Surveillance Study from the SEER program under a modification to contract N01-PC-35136. 

In the second study, researchers evaluated how neighborhood environments may influence body size among breast cancer survivors. They found breast cancer survivors were more likely to be overweight or obese if they resided in neighborhoods of lower socioeconomic status with more minorities, with more traffic, with more car commuters, and with more fast food restaurants. 

A higher relative prevalence of overweight individuals was seen for African Americans, U.S.-born Asian Americans/Pacific Islanders and foreign-born Hispanics. A higher relative prevalence of obesity was seen among African Americans and Hispanics. These racial/ethnic differences remained after accounting for neighborhood factors.

As maintaining a healthy body weight is a key modifiable factor for optimizing breast cancer survivorship outcomes, this study suggests that breast cancer survivors’ neighborhood environments may impact the risk of quality of life, recurrence, and survival.

Participants were drawn from 4,505 breast cancer survivors participating in the Pathways Study, a study led by Kaiser Permanente Northern California. The Pathways Study is designed to examine the effects of lifestyle, use of complementary and alternative therapies, and molecular and biological factors on cancer outcomes.

The Pathways Study is funded by the National Cancer Institute, National Institutes of Health (R01CA105274 and U01CA195565). The development of the California Neighborhoods Data System was supported by National Cancer Institute grant R03 CA117324 and by a Rapid Response Surveillance Study from the SEER program under a modification to contract N01-PC-35136. 

In the third study, researchers examined the separate and combined effects of participant and neighborhood factors on breast cancer risk. They also evaluated how these effects may differ in different racial/ethnic groups, including white, African American, U.S.-born Hispanics, and foreign-born Hispanics. 

Researchers found that neighborhood socioeconomic status played a role in determining risk of breast cancer, even after accounting for participant’s own educational level. Women living in the highest socioeconomic status neighborhoods were nearly two times more likely to develop breast cancer than those in the lowest socioeconomic status neighborhoods. Urban built environment characteristics appear to explain some of these patterns, especially among African American and Hispanic women. 

The Neighborhoods and Breast Cancer Study included data from the San Francisco Bay Area Breast Cancer Study and the Northern California Breast Cancer Family Registry.  

This work was supported by National Cancer Institute grant R01CA140058. 

About the Cancer Prevention Institute of California
The Cancer Prevention Institute of California is a nonprofit organization dedicated to preventing cancer and to reducing its burden where it cannot yet be prevented. We are the only freestanding research institution working solely to prevent cancer using extensive population data. Our researchers study a wide range of cancer risk factors, such as racial/ethnic background, socioeconomic status, age, occupation, gender, genetic predisposition, geographic location, environment and lifestyle to determine how these factors affect frequency, distribution and types of cancers. For more information, visit the CPIC website at www.cpic.org

Media Contact: 
Donna Lock, 510-608-5160 | donna.lock@cpic.org


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