Carcinoma of unknown primary is a rare and often hostile type of cancer. Cancers form from multiple cells in one area of the body and can spread to other areas. In carcinoma of unknown primary, the spreading of the cells can be found; however, doctors can’t determine the precise location or organ where the cancer began. CUP has been reported to comprise of approximately 5% of all cancer cancers. Even with the availably of sophisticated imaging techniques and various therapy treatments, CUP remains a challenge and can be determined only  by pinpointing the precise location of the cancer and gathering as much information on it in order to select the best and the most appropriate treatment.

Most cancers of unknown primary (CUP) are carcinomas.  They are subdivided into:

  • Germ cell tumours
  • Squamous cell tumours
  • Neuroendocrine tumours
  • Carcinoma of solid tumours
  • Adenocarcinoma



Signs and symptoms of carcinoma of the unknown primary typically depend on where in the body the cancer has spread. Most common symptoms of CUP include:

  • Lump in any part of the body
  • Weight loss or loss of appetite
  • Chest pain
  • Tiredness
  • Night sweats
  • Fever
  • Recurring pain in one part of the body
  • Coughing
  • Skin tumors
  • Change in bowel movements
  • Unusual bleeding or discharge



The direct causes for cancer of the unknown primary cannot be specified because determining what type of cancer an individual possesses is key. Each type of cancer has different causes, for example smoking most often causes lung cancer and the sun most often causes skin cancer. Carcinoma of the unknown primary has been linked to be found with cancers often related to smoking (cancer in the lung, pancreas, kidney, larynx and oesophagus); so quitting smoking is always a good way to lower the chance or developing cancer.  However, in order to pinpoint the exact cause, determining the precise location of the cancer is vital. In carcinoma of the unknown primary, this remains unknown.


Risk factors 

Factors associated with an increased risk of developing CUP include the following:

  • Being a smoker
  • Being overweight
  • Malnutrition and diet
  • Damage to the skin by sun radiation



Since Cancer of unknown primary (CUP) represents a number of different cancers, there is no known way to prevent it. However, certain lifestyle changes can help reduce the risk of developing certain cancers. These include:

  • Quitting smoking
  • Limiting alcohol consumption
  • Maintaining a healthy diet
  • Staying at a healthy weight
  • Exercising regularly