Cancer risk factors and access to cancer prevention services for people experiencing homelessness

Cancer is one of the most pressing global health issues, and populations with complex needs, such as people experiencing homelessness, have higher cancer incidence and mortality rates compared with the housed population. We mapped the evidence on cancer risk factors as well as barriers and facilitators to cancer prevention services among people experiencing homelessness, which is key to localising research gaps and identifying strategies for tailored interventions adapted to people experiencing homelessness. The results of 40 studies contribute to an understanding of the dynamic, interactive factors at different levels that determine access to cancer prevention services: socioeconomic, psychological, and physical factors (individual level); practical support and relational loops between health-care providers and people experiencing homelessness (interpersonal level); housing and regular medical care (system level); and interventions to facilitate access to cancer prevention (policy level). Furthermore, studies reported higher prevalence of various cancer-associated risk factors among people experiencing homelessness with the most common being tobacco use, ranging from 26% to 73%. The results show the importance of interventions to facilitate cancer prevention services through social support and low-threshold interventions (eg, navigation programmes), and training health-care staff in creating supportive and trusting environments that increase the likelihood of the continuity of care among people experiencing homelessness.