Cancers are usually named after the part of the body where they first start to grow. Cancer of unknown primary (CUP) is a term used when cancer has been diagnosed but the original (primary) place where the cancer started cannot be found.
In people with a cancer of unknown primary, the cancer is only diagnosed because it has spread to somewhere else in the body and caused symptoms. Common places where cancer can spread include the liver, lungs and bones.
Incidence and mortality data are currently available up until 2016.
View more information on how the above incidence, mortality and survival data was calculated