The value of research collaborations and consortia in rare cancers.

Rare cancers are defined by an incidence of less than six per 100,000 people per year. They represent roughly 20% of all human cancers and are associated with worse survival than are so-called frequent tumours, because of delays to accurate diagnosis, inadequate treatments, and fewer opportunities to participate in clinical trials (because of a paucity of dedicated trials from both academic and industrial sponsors). In this Series paper, we discuss how these challenges can be addressed by research consortia and suggest the integration of these consortia with reference networks, which gather multidisciplinary expert centres, for management of rare tumours.