Placing Biology in Breast Cancer Disparities Research

Abstract

An emerging consensus among social, behavioral, and biological scientists suggests that the social environment has a profound influence on individual health through multiple pathways across the life course. Studies examining key periods of development in children suggest that while inheritance of genetic traits predisposes children to certain health and disease outcomes, chronic psychosocial stress in early development and throughout the life span may interact with gene expression and subsequently add greater health vulnerability in adulthood. The pathways through which the social environment can affect biology is only beginning to be understood, yet social scientists have long argued that neighborhoods generate a sense of identity and inclusion and have real consequences on the type, quality, and quantity of resources that are accessible for individuals and groups. Residence in communities, noted by economic inequality and social disconnection can have negative consequences on a myriad of outcomes related to health and well-being.

This chapter explores the effects of neighborhoods on individual health, with special attention paid to the ways the environment positively and negatively influences biology over the life course. We discuss our own model at the Center for Interdisciplinary Health Disparities Research (CIHDR) as a means for understanding the pathways through which the social environment can “get under the skin” to affect health, in our case breast cancer. The transdisciplinary model explores how real and imagined social environments impact psychological states and physiological processes, in turn influencing gene expression, cell survival, and tumor growth in breast cancer. Additionally, we discuss our animal work as a method for exploring the effect of social environment on health. Our rodent models have provided inputs to human studies because (1) we can manipulate social conditions, such as social isolation, and observe this affect on behavioral and biological outcomes and (2) we can take a life span perspective on these changes, because the animals live an average of 900 days. In both human and animal research, a range of environments, physical, built, and perceived, can be measured that create daily stressors (e.g., high crime neighborhoods in humans or a overturned food dish in open-caged rats) or ameliorate them (e.g., collective efficacy in humans or returning an animal that was isolated to its social group), as well as the presence or absence of social support and affiliation in the face of these stressors

We further explore current ways to capture neighborhood characteristics in research and their efficacy is measuring their impact on health. We discuss our own tool for measuring the built environment, defined as features of the four-block area around participants’ home. Investigators at the CIHDR examine the built environment through observer-rated surveys that capture the immediate physical characteristics of the respondent’s neighborhood that foster or diminish opportunities for interaction, monitor behavior, and provide resources. These data will subsequently be used to understand the association between neighborhood aesthetics, resources, and features, crime and census level data, psychological response, and ultimately biological outcomes.