Carcinoma of unknown primary is a diagnosis given when doctors can't determine where a cancer began. Carcinoma of unknown primary is rare, and it can be an aggressive type of cancer.

Cancers form from mutated cells in one area of the body and can spread (metastasize) to other areas. In carcinoma of unknown primary, the metastasized cells are discovered, but the tumor where they began can't be found.

Knowing where a cancer began plays a role in determining the best treatment. For this reason, doctors who treat people with carcinoma of unknown primary work to locate the organ where the cancer began.

When that can't be determined, doctors use as many clues as they can gather to select the most appropriate treatment for carcinoma of unknown primary. As researchers are improving molecular testing and other innovative laboratory testing done on cancer cells, the need to locate the primary site may become less important.

  • Collaboration. At Mayo Clinic, medical oncologists, radiation oncologists, surgeons, radiologists and pathologists work as a multidisciplinary team to provide whole-person care to those with carcinoma of unknown primary. Other professionals are included as needed.
  • The latest technology to aid in diagnosis. Mayo Clinic doctors have access to the latest technology to help them investigate where carcinoma of unknown primary began. Even when a primary site can't be determined, these tests give doctors clues that aid in selecting the best treatment.

    Radiologists use advanced imaging technology to search for signs of cancer.

    Pathologists have cutting-edge laboratory tests available to analyze cancer cells for clues of their origin. Doctors and hospitals around the world send biopsy samples to Mayo Clinic pathologists for evaluation.

  • Experience. Carcinoma of unknown primary is an uncommon type of cancer. Mayo Clinic doctors have experience treating many cases of carcinoma of unknown primary.
  • A full range of treatment options to consider. Mayo Clinic doctors will work with you to review all of your treatment options and choose the treatment that best suits your needs and goals. The range of treatments offered to people with carcinoma of unknown primary includes chemotherapy, radiation and surgery.
  • Comprehensive cancer center. Mayo Clinic Cancer Center meets strict standards for a National Cancer Institute comprehensive cancer center, which recognizes scientific excellence and a multidisciplinary approach to cancer prevention, diagnosis and treatment.

Mayo Clinic in Rochester, Minn., Mayo Clinic in Jacksonville, Fla., and Mayo Clinic in Scottsdale, Ariz., are ranked among the Best Hospitals for cancer by U.S. News & World Report.

Mayo Clinic works with hundreds of insurance companies and is an in-network provider for millions of people. In most cases, Mayo Clinic doesn't require a physician referral. Some insurers require referrals or may have additional requirements for certain medical care. All appointments are prioritized on the basis of medical need.

Specialists in oncology, pathology and radiation oncology at Mayo Clinic care for people with carcinoma of unknown primary.

For appointments or more information, call the Central Appointment Office at 800-446-2279 (toll-free) 8 a.m. to 5 p.m. Mountain Standard Time, Monday through Friday or complete an online appointment request form.

Specialists in oncology, pathology and radiation oncology at Mayo Clinic care for people with carcinoma of unknown primary.

For appointments or more information, call the Central Appointment Office at 904-953-0853 8 a.m. to 5 p.m. Eastern time, Monday through Friday or complete an online appointment request form.

Specialists in oncology, pathology and radiation oncology at Mayo Clinic care for people with carcinoma of unknown primary.

For appointments or more information, call the Central Appointment Office at 507-538-3270 7 a.m. to 6 p.m. Central time, Monday through Friday or complete an online appointment request form.

See information on patient services at the three Mayo Clinic locations, including transportation options and lodging.

Cancer research is conducted in coordination with the Mayo Clinic Cancer Center.

The Mayo Clinic Cancer Center receives funding from the National Cancer Institute and is designated as a comprehensive cancer center — recognition for an institution's scientific excellence and multidisciplinary resources focused on cancer prevention, diagnosis and treatment.

Publications

See a list of publications by Mayo Clinic authors on carcinoma of unknown primary on PubMed, a service of the National Library of Medicine.

Oct. 29, 2015