A randomized controlled trial of the effectiveness of a one-to-one peer support intervention on resilience, social support, and salivary cortisol in recently diagnosed women with breast cancer.

Purpose: Peer support has been suggested as a way to help women diagnosed with breast cancer to better cope with their situation, but studies on its effectiveness have conflicting results. This randomized controlled trial aimed to study the effectiveness of a one-to-one peer support intervention on psychological resilience, social support, and salivary cortisol among breast cancer patients.

Methods: The sample consisted of 121 newly diagnosed women at Onkologikoa Hospital. Patients who were prescribed chemotherapy were randomly assigned to Intervention Group 1 (IG1) or Control Group 1 (CG1). Similarly, those prescribed adjuvant radiotherapy were assigned to IG2 or CG2. Women in IG1 received 8 biweekly social support sessions from volunteer survivors who had successfully overcome breast cancer, while IG2 received 6 biweekly sessions. CG1 and CG2 only received standard care. Resilience, social support, and salivary cortisol were assessed at baseline (T1) and at the end of the intervention (T2).

Results: We found a non-significant, yet a small to moderate size increase in resilience from T1 to T2 in IG1 (p = 0.246; dDc = 0.47). Upon regression analysis, we observed that this increase was determined by changes in cortisol (β = -0.658, p = 00.010), affective support (β = -0.997, p = 00.014), and emotional support (β = 0.935, p = 00.008). We also found a significant decrease in resilience levels in CG2 from T1 to T2 (p = 0.003; dDc = 0.88).

Conclusion: The present study suggests that peer support can exert a protective psychological influence on women diagnosed with breast cancer, and further indicates an exciting avenue for future intervention development in the breast cancer care continuum.

Trial Registration: ClinicalTrials.gov NCT05077371.