Unknown Primary: Statistics

Approved by the Cancer.Net Editorial Board, 03/2015

ON THIS PAGE: You will find information about how many people are diagnosed with this type of cancer each year. You will also learn some general information on surviving the disease. 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 34,170 people will be diagnosed with CUP this year in the United States (17,810 men and 16,360 women), 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.

It is estimated that 42,700 deaths (23,900 men and 18,880 women) from this disease will occur this year.

People diagnosed with CUP are a diverse group, and prognosis, which is the chance of recovery, varies widely. When all CUP types are looked at together, average survival time is about 9 to 12 months after diagnosis. However, survival rates vary greatly depending on the where the cancer is located and if it has spread, cancer cell type, treatments and more.

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.

It is important to remember that statistics on how many people survive this type of cancer are an estimate. The estimate comes from data based on thousands of people with CUP in the United States each year. So, your own risk may be different. Doctors cannot say for sure how long anyone will live with CUP. Learn more about understanding statistics.

Statistics adapted from the American Cancer Society.

The next section in this guide is Risk Factors. It explains what factors may increase the chance of developing this disease. Or, use the menu on the side of your screen to choose another section to continue reading this guide