Effects of Within-Group Heterogeneity on Cancer Control Outcomes in Underrepresented Populations

Overview

The goal of this Notice of Special interest (NOSI) from the National Cancer Institute (NCI) is to support administrative supplements for currently funded investigators to better understand within-group factors that contribute to cancer prevention and control outcomes and intervention effectiveness in populations that are underrepresented in or excluded from cancer research. This administrative supplement would provide funding for one year to initiate or enhance evaluation of heterogeneity within populations and/or how this heterogeneity influences cancer outcomes, within the scope of the parent grant.

For this Notice, applications should focus on heterogeneity within under-resourced settings and/or among populations that are traditionally underrepresented in or excluded from behavioral research, including minoritized racial and ethnic groups, socioeconomically disadvantaged populations, rural populations, LGBTQ+ individuals, and individuals living with intellectual or physical disabilities.

Background

Significant heterogeneity within broad sociodemographic groups can influence health behaviors, health outcomes, and intervention effectiveness. Individuals within broad categories of underrepresented groups can have different lived experiences, health behaviors, risk factors (e.g., environmental exposures, genetic predispositions), and needs (e.g., individual, interpersonal, structural). For example, racial and ethnic categories include individuals from many countries of origin, speaking different native languages, across varied socioeconomic strata, living in rural and urban settings, and with different US acculturation levels. There is substantial variation in cancer risk and mortality based on these and other within-group factors. Furthermore, structural systems and stigmas may act synergistically to amplify health inequities among individuals with multiple marginalized identities.

However, research efforts often lack the samples, measures, and methods to account for such heterogeneity. Between-group comparisons and estimates of average effects are common in health disparities research but may reify group-based differences and mask meaningful within-group differences. For example, cancer rates may not differ when Asian Americans are compared to non-Hispanic White Americans, but disaggregating Asian Americans by country of origin may reveal stark disparities that are masked at the aggregate level because of high rates among some subgroups and low rates among others. Similarly, measurement and analysis of race/ethnicity, sexual and gender identity, and social determinants of health within a study population of low-income adults may uncover important variation that predicts intervention effectiveness.

Efforts to improve cancer prevention and control outcomes for all individuals require expanded understanding of multi-level factors underlying cancer outcomes within populations, especially among smaller subgroups or those with multiple marginalized identities. Research supported by this supplement aims to contribute to the understanding how heterogeneity affects the distribution of cancer risk, the efficacy of cancer prevention and treatment efforts, and the experience of cancer and treatment-related symptoms and side effects.