Background: Because of medical advances, metastatic breast cancer (MBC) is now viewed as a chronic disease, rather than an imminent death sentence. Helping women live with this disease requires more than a medical approach to symptoms. Thus, a mentor-based and supportive-expressive program 'Be Resilient to Breast Cancer' (BRBC) was designed to help Chinese women with MBC enhance their resilience levels, biopsychosocial functions, and potentially extend their life span. Methods: A total of 226 women with MBC were randomly assigned, in a 1 : 1 ratio, to an intervention group (IG) that participated in BRBC or to a control group (CG) that received no intervention. Be Resilient to Breast Cancer was conducted for 120 min once a week. Primary outcomes were cancer-specific survival and secondary outcomes were resilience, Allostatic Load Index (ALI), anxiety, depression, and quality of life (QoL). The Cox proportional-hazards model was used for survival analysis and growth mixture models were performed for secondary outcomes. Results: Be Resilient to Breast Cancer did not significantly prolong 3-or 5-year survival (median survival, 36.7 months in IG and 31.5 months in CG). The hazard ratio for death was 0.736 (95% CI, 0.525-1.133, P = 0.076; univariate Cox model) and 0.837 (95% CI, 0.578-1.211, P = 0.345; multivariate Cox analysis). The IG improved in anxiety (ES = 0.85, P<0.001), depression (ES = 0.95, P<0.001), QoL (ES = 0.55, P<0.001), resilience (ES = 0.67, P<0.001), and ALI (ES = 0.90, P<0.001) compared to CG. Conclusions: BRBC does not improve survival of women with MBC in this study, though longer follow up is warranted. It positively impacts resilience, QoL, ALI, and emotional distress.