Symptoms of cancer of unknown primary

Cancer of unknown primary (CUP) can cause different signs and symptoms depending on where the cancer is in the body. The general signs or symptoms of cancer of unknown primary are often the same as those found in people with advanced cancer from a known type of cancer. Other health conditions can cause the same symptoms as CUP.

The general symptoms of CUP include:

  • unexplained weight loss
  • unexplained fatigue
  • loss of appetite

CUP usually causes specific signs and symptoms depending on where the cancer has spread and which organs it affects. These symptoms include:

  • a lymph node in the neck, under the arm or in the groin that is larger than normal, or enlarged (the lymph node usually isn’t sore or tender)
  • shortness of breath, coughing and trouble breathing
  • a lump or swelling that can be felt in the abdomen or enlargement of the abdomen
  • pain in the chest, abdomen, bones or other parts of the body
  • low red blood cell counts (called anemia) caused by bleeding in the gastrointestinal (GI) tract or cancer in the bone marrow
  • headaches or other neurological symptoms (such as confusion, memory problems or problems walking)

Expert review and references

  • American Cancer Society. Cancer - Unknown Primary. Atlanta, GA: 2014: https://www.cancer.org/.
  • Greco FA & Hainsworth JD . Cancer of unknown primary site. DeVita VT Jr, Lawrence TS, & Rosenberg SA. Cancer: Principles & Practice of Oncology. 10th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2015: 113:1720-1737.
  • Hainsworth JD, Greco FA . Neoplasms of unknown primary site. Hong WK, Bast RC Jr, Hait WN, et al (eds.). Holland Frei Cancer Medicine. 8th ed. People's Medical Publishing House; 2010: 120: 1713-1722.
  • Kim KW, Krajewski, KM, Jagannathan JP, et al . Cancer of unknown primary sites: what radiologists need to know and what oncologists want to know. AJR: American Journal of Roentgenology. The American Roentgen Ray Society; 2013.
  • Macmillan Cancer Support. Cancer of unknown primary (CUP). London, UK: Macmillan Cancer Support; 2014: https://www.macmillan.org.uk/.

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