Purpose of review: More than 50% of all gynecologic cancers can be classified as rare tumors (defined as an incidence of <6 per 100 000) and as such represent a major challenge for clinicians.
Recent findings: The rapidly increasing number of targeted therapies provides a unique opportunity to improve treatment options of rare gynecologic cancers; however, their low frequency makes it difficult to test these new agents. Harmonization of medical practices and novel trial designs are needed to identify and develop new treatments for rare gynecologic tumors.
Summary: This requires international partnerships, harmonization of treatment recommendations, and international collaborations to overcome existing regulatory barriers in international trials. Whereas randomized trials may be possible in some rare tumor types, there are others for which conducting even single arm studies may be challenging. For these very rare tumors, robust collection of data through national registries could lead to improvements in treatment.