When uncertainties regarding the clinical evidence have been too great for National Institute for Health and Care Excellence (NICE) to recommend routine commissioning, managed access agreements have allowed patients to be treated while additional data are collected.

Immature survival data are an important source of clinical uncertainty, which has largely been addressed by later follow-up of patients in clinical trials rather than by additional real-world data.

Systemic Anti-Cancer Therapy data (an important English source of real-world data) have been used to address a limited number of clinical uncertainties.