Lu Yang, Caroline de Moel-Mandel, Kai Wallens, Chris Lynch
Social media offers scalable opportunities for social connection and health communication; however, its role in cancer interventions remains unclear. This systematic review examines the use of social media in cancer-related health interventions and their targeted outcomes. The review was registered with PROSPERO and conducted according to the PRISMA guidelines. Seven databases were searched for English-language randomized controlled trials (RCTs) (2000-2024) evaluating cancer interventions with a social media component. Eligible studies involved adults (≥18 years) with a cancer diagnosis and reported outcomes related to physical, psychological, or social well-being. Intervention characteristics were categorized by social media role, intended effects, and platform affordances. Seventeen RCTs were included. Quality of life was the most assessed outcome, with frequent improvements in psychosocial measures (e.g., anxiety, depression, and social support) and some physical benefits (e.g., fatigue, pulmonary function, and daily step count). WeChat was the dominant social media platform, followed by Facebook. Most interventions delivered education, social support, and disease management, although few studies measured actual platform usage. The reported effects were shaped by common platform affordances, flexibility, structure, adaptation, narration, and identity, which enabled private communication, real-time clinician support, narrative sharing, and tailored guidance. Findings suggest that social media platforms can enhance well-being, self-management, and social support for people living with cancer when these features are intentionally aligned with communication and behavior-change mechanisms. This review underscores the importance of theory-informed, context-specific design, rather than assuming benefit from social media use alone.