Thomas Powles, MBBS, MRCP, MD, Barts Cancer Institute, London, UK, gives an overview of the use of adjuvant immune checkpoint blockade in high-risk urothelial and kidney cancer, discussed at the European Society for Medical Oncology (ESMO) 2021 congress. Dr Powles outlines the controversy surrounding this topic, and highlights the importance of clinical trial data and more specifically, overall survival. This interview took place at the European Society for Medical Oncology (ESMO) 2021 congress.