Rare cancers account for 27% of all new cancer diagnoses in the US and 22% of all new cancer diagnoses in the EU. With the shift toward grouping cancer based on molecular subtypes rather than by location and tissue type, some common cancers are now categorized as groups of rare cancers. For example, melanoma as a whole is not considered a rare cancer, but when divided into molecular subtypes, it can be viewed as a collection of rare cancers. When grouped as families, the most common rare cancer types are hematological, female genital tract, gastrointestinal, and head and neck malignancies.
Grouping cancer based on molecular subtypes has changed not only how tumors are categorized, but also how novel therapeutics are studied in clinical trials. In this discussion, we explore the landscape of rare cancer clinical trials, from key considerations for study design and the value of biomarkers to the importance of the patient perspective and the options for speeding much-needed therapies to market.