Epidemiology and Management of Neuroendocrine Neoplasms of Unknown Primary in Switzerland.
BACKGROUND Neuroendocrine neoplasms (NEN) are mainly located in the gastrointestinal tract or the lungs. In up to 14%, the primary tumor remains unidentified, classified as cancer of unknown primary (CUP). Due to their rarity and heterogeneity, CUPs are poorly studied. METHODS Retrospective data analyses with data pr...