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Survival Rates for Cancer of Unknown Primary

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Survival rates tell you what portion of people with the same type and stage of cancer are still alive a certain amount of time (usually 5 years) after they were diagnosed. They can't tell you how long you will live, but they may help give you a better understanding about how likely it is that your treatment will be successful.

Cancer of unknown primary (CUP) includes many different cancer types, so it’s hard to provide meaningful survival statistics for these cancers as a group. In general, these are difficult cancers for several reasons:

  • When they are first diagnosed, these cancers have already spread beyond the site where they started. This means that the types of treatments that are most likely to be successful, such as surgery or radiation therapy, are not likely to result in a cure in most cases.
  • Because the exact type of cancer is not known, it’s harder for doctors to know what treatment is most likely to help the patient.
  • Many CUPs are fast-growing and/or fast-spreading cancers.

When all types of CUP are included, the average survival time is about 9 to 12 months after diagnosis. But this can vary widely depending on many factors, including the cancer cell type, where the cancer is found, how far the cancer has spread, a person’s general health, the treatments received, and how well the cancer responds to treatment.

Survival statistics can sometimes be useful as a general guide, but they may not accurately represent any one person’s prognosis (outlook). This is because survival rates are often based on previous outcomes of large numbers of people who had the disease, but they can’t predict what will happen in any particular person’s case. Your doctor is familiar with your situation; ask how these numbers may apply to you.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

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National Cancer Institute. Physician Data Query (PDQ). Cancer of Unknown Primary Treatment. 07/25/2015. Accessed at: on February 9, 2018.

Raghav K, Mhadgut H, McQuade JL, Lei X, Ross A, Matamoros A, Wang H, Overman MJ, Varadhachary GR. Cancer of unknown primary in adolescents and young adults: Clinicopathological features, prognostic factors and survival outcomes. PLoS One. 2016 May 12;11(5):e0154985. doi: 10.1371/journal.pone.0154985.

Varadhachary GR, Lenzi R, Raber MN, Abbruzzese JL. Carcinoma of Unknown Primary In: Neiderhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, PA. Elsevier: 2014:1792-1803.

Last Revised: March 9, 2018

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