Unknown Primary: Statistics

Approved by the Cancer.Net Editorial Board, 03/2014

ON THIS PAGE: You will find information about how many people learn they have this type of cancer each year and some general survival information. Remember, survival rates depend on several factors. To see other pages, use the menu on the side of your screen.

The exact number of people diagnosed with CUP each year is not known because some cancers start out being classified as unknown primary, only to have the primary cancer found later. However, an estimated 31,430 people will be diagnosed with CUP this year in the United States, which accounts for approximately 2% of all cancers. As new tests that can more accurately determine where a cancer started become available, the number of people diagnosed with CUP will continue to decrease.

People diagnosed with CUP are a diverse group, and prognosis, which is the chance of recovery, varies widely. Often, there are not as many treatments available for people with cancer that has already spread to other parts of the body at diagnosis. However, others have a cancer that can be successfully treated. These differences and survival rates are discussed in the Treatment Options section.

Cancer survival statistics should be interpreted with caution. Estimates are based on data from thousands of people with this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with CUP. Learn more about understanding statistics.

Statistics adapted from the American Cancer Society.

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