The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Cellular Classification ¹

Added text ² on gene expression profiling as a diagnostic test (cited Horlings et al. as reference 6).

Added text ³ on the use of molecular profiling to identify tissue of origin (cited Varadhachary et al. as reference 12).

Newly Diagnosed Carcinoma of Unknown Primary ⁴

Added text ⁵ to state that intensity-modulated radiation therapy may have less short- and long-term toxicity than conventional radiation therapy in terms of xerostomia, acute dysphagia, and skin fibrosis (cited Madani et al. as reference 5).