Cancer of unknown primary origin

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Cancer of unknown primary origin (CUP), also known as occult primary cancer, is a type of cancer in which metastatic cancer cells are found in the body, but the place where the cancer began (the primary site) is not known. CUP is a rare condition, accounting for approximately 3-5% of all cancer diagnoses.

Classification

CUP can be classified based on the type of cells that are found in the metastatic tumors. The main types include:

• Adenocarcinoma of unknown primary
• Squamous cell carcinoma of unknown primary
• Neuroendocrine carcinoma of unknown primary
• Poorly differentiated carcinoma of unknown primary

Symptoms

The symptoms of CUP can vary widely depending on where the metastatic cancer cells are located. Common symptoms include:

• Unexplained weight loss
• Fatigue
• Pain in the affected area
• Swollen lymph nodes
• Loss of appetite

Diagnosis

Diagnosing CUP involves a series of tests and procedures to try to locate the primary site of the cancer. These may include:

• Biopsy
• Imaging studies such as CT scan, MRI, and PET scan
• Blood tests
• Endoscopy

Treatment

The treatment for CUP depends on several factors, including the type of cancer cells found, the location of the metastases, and the patient's overall health. Common treatment options include:

• Chemotherapy
• Radiation therapy
• Targeted therapy
• Immunotherapy
• Surgery

Prognosis

The prognosis for patients with CUP varies widely and depends on several factors, including the type of cancer cells, the extent of the disease, and the patient's overall health. Generally, the prognosis is poorer compared to cancers with known primary sites.

Research

Ongoing research is focused on improving the diagnosis and treatment of CUP. Advances in molecular biology and genomics are helping to identify potential primary sites and develop targeted therapies.

See also

• Metastasis
• Oncology
• Cancer staging
• Cancer treatment