<qa>  What is the gold standard for a randomized trial?Due to better treatment options and earlier detection, survival rates of patients with breast cancer continue to increase. As such, late treatment toxicity, long-term quality of life and the cosmetic outcome are becoming more important. Also, many competing experimental interventions e.g. treatment, lifestyle interventions for breast cancer are being developed, all in need to be properly evaluated before being implemented in routine clinical care. Randomized Controlled Trials are the gold standard to do so, but they have shown many challenges, especially when applied in a cancer setting. The cohort multiple Randomized Controlled Trial cmRCT design is a promising design for multiple simultaneous randomized evaluations of experimental interventions, with potential for increased recruitment, comparability and long-term outcomes as a standard. 