The rapid development of multiple new actionable biomarkers in oncology has transformed how we treat cancer patients. In the last 5 years, more than 60% of oncology drugs have been approved based on specific biomarkers, requiring biomarker testing to determine the best treatment options, and meaning that many cancer types that were previously common are now rare (defined by specific biomarker status). What are the implications of this for real-world research?

In this presentation, we will discuss what constitutes a rare cancer, the challenges and opportunities associated with studying small patient populations, and the ways in which analytic approaches must be adapted to generate robust real-world evidence and insights and make reliable inferences.