Cancers of unknown primary (CUP) have always spread outside the organ they started in by the time they are diagnosed. If they had been found early, we would know where they started and they would not be classified as a cancer of unknown primary.
The American Cancer Society has specific recommendations about tests that may help detect breast, prostate, cervical, and colorectal cancers early, before they cause any symptoms. The Society also recommends routine cancer-related checkups that may detect skin, thyroid, mouth, and some other cancers at an early stage.
But these cancers account for a fairly small portion of cancers of unknown primary. No screening tests have been proven to be effective in the early detection of many of the cancers that are likely to be diagnosed as cancer of unknown primary, such as pancreatic, stomach, and kidney cancers.
Last Revised: 01/27/2016