How effective is peer-to-peer support in cancer patients and survivors? A systematic review

PURPOSE: Core components of peer-to-peer (PTP) support for cancer survivors include informational, emotional, and psychosocial aspects. Previous literature on peer support in cancer includes both professionally and peer-led support. Our objective was to summarize studies on the effects of non-professionally led PTP support in cancer. METHODS: We performed a systematic research on studies in PTP support of adult cancer survivors with an interventional design, comparing outcomes of PTP support against any control. We included all studies with a precise definition of a PTP support, published from January 2000 up to March 2023 in peer-reviewed journals in English or German. RESULTS: Out of N = 609 identified publications, we were are able to include n = 18 randomized-controlled trials (RCTs) fulfilling our inclusion criteria. Main settings were dyadic support via telephone, face-to-face (FTF), and web-based online support. Most common outcomes were distress, depressive symptoms, anxiety, and quality of life (QoL). Overall, we found only small effects of PTP support on depression/anxiety, coping, or sexual functioning. Beneficial effects associated with the PTP intervention were apparent in particular in BRCA, in FTF settings, and in assessments of cancer-specific QoL outcomes. CONCLUSION: This review shows that there are a few RCT investigating the effect of PTP support with short-term effects. Overall, there is a need for more RCTs with high methodological standards to evaluate the effectiveness of PTP support.