Background <p>Ethnic enclaves (EEs) are culturally distinct neighborhoods, and complex relationships may exist between living in EEs and cancer outcomes. Given the increasing demographic diversity, expansion of EEs, and ongoing burden of cancer in the U.S., a growing body of literature focuses on the enclave-cancer relationships. This review aims to describe the scope, assess methods, synthesize existing evidence, and identify research gaps on this topic.</p> Methods <p>Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we found 34 empirical studies, published between January 2000 and May 2023, that examined how living in EEs may relate to various cancer outcomes, including incidence, diagnosis, treatment, and survival.</p> Results <p>Most studies examined the relationships between residing in Hispanic or Asian enclaves and cancer incidence or survival in California. Studies used divergent methods to identify EEs, and results were mixed among null, protective, and risk findings. Studies explored several cancer types, with breast and colon cancers being the most studied, and findings also varied by patients' race&#xa0;and&#xa0;ethnicity, sex, and neighborhood socioeconomic status (SES). The small number of studies limits the power to draw statistical conclusions from the existing literature.</p> Conclusions <p>More research is needed to adequately explore enclave-cancer relationships among diverse populations across different U.S. regions, and to comprehensively investigate potential moderators and mediators connecting EEs and cancer outcomes. Future studies may benefit from conceptualizing and operationalizing EEs based on demographic, geographic, economic, and cultural characteristics, and recognizing varying SES, immigrant concentrations, and racial/ethnic subgroup compositions across EEs.</p>