Mapping Systematic Reviews of Breast Cancer Survivorship Interventions: A Network Analysis

PURPOSE: Despite a large volume of research, breast cancer survivors continue to experience high levels of unmet need. To better understand the breadth of evidence, we mapped systematic review-level evidence across cancer survivorship domains and outcomes and conducted network analyses of breast cancer survivorship care interventions. METHODS: Umbrella review methodology was used to identify published systematic reviews reporting on survivorship care interventions for breast cancer survivors. Included reviews were mapped against domains and health care outcomes as specified by the Cancer Survivorship Quality Framework, and network analyses were conducted to determine the extent of clustering of reviews, and connectivity across domains and outcomes. RESULTS: Of 323 included reviews, most focused on management of physical (71.5%) or psychologic (65.3%) effects, health-related quality of life (55.1%), and physical activity (45.2%). Few focused on financial/employment effects, chronic conditions, health care delivery domains, or health service use or cost outcomes. Network analysis indicated 38.6% of reviews were connected to a single domain, 35.0% to two domains, and 16.5% to three domains, indicating a relatively siloed nature of research, with greater community clustering between health care delivery domains but limited connection between these and the other domains. Reviews published between 2011 and 2021 were more likely to examine financial toxicity and chronic conditions, but these domains remained under-represented compared with physical and psychologic effects. CONCLUSION: Despite vast volume of breast cancer survivorship intervention research, systematic review-level research is unevenly distributed, siloed, and with significant gaps in key domains and outcomes. Assessment of evidence gaps in primary research and strategic planning of future research, in consultation with survivors, is needed.