New era:prospects for managing cancer of unknown primary

Cancer of unknown primary(CUP)is a highly heterogeneous tumor type that is confirmed to be metastatic through pathological examination;however,its primary lesion cannot be determined on the basis of detailed clinical information and diagnostic methods.The current guidelines have not changed the basic definition of CUP.Some studies have reported a decline in the incidence of CUP,to approximately 2%1,with the development of diagnostic techniques such as radiology,histopathology,and genetic testing.