Cancer of Unknown Primary Origin

What Is Cancer of Unknown Primary Origin?

Most cancers are classified by the organ or tissue where they first develop, such as breast, lung, or prostate cancer. Cancer of unknown primary origin (often referred to as CUP) is diagnosed when cancer cells are found in the body but the location where the cancer began cannot be identified. Because the primary site is unknown, CUP is not a single disease but rather a group of cancers with different characteristics.

What Causes Cancer of Unknown Primary Origin?

The exact cause of CUP is not fully understood. Like other cancers, CUP develops when normal cells acquire genetic changes that cause them to grow uncontrollably. In CUP, the site where these changes first occurred cannot be determined, even with detailed evaluation. This uncertainty makes CUP more complex, as the underlying cause and behavior of the cancer may differ depending on the type of cells involved.

How Is Cancer of Unknown Primary Origin Detected?

Our specialists take a comprehensive approach by reviewing medical, surgical, social, and family history, performing laboratory testing, and using imaging studies. If cancer is suspected, diagnostic tools may include:

• CT scan (Computed Tomography): Creates detailed three-dimensional images using X-rays.
• MRI (Magnetic Resonance Imaging): Uses magnetic fields to provide high-resolution images of organs and tissues.
• PET scan (Positron Emission Tomography): Uses a radioactive tracer to detect cancer cells based on their activity.
• PET-CT scan: Combines CT and PET imaging for greater accuracy.
• Ultrasound: Uses sound waves to visualize organs and tissues.

If a suspicious mass is identified, a biopsy is usually required to examine tissue under a microscope and confirm the diagnosis.

Signs and Symptoms of Cancer of Unknown Primary Origin

CUP can cause a wide variety of symptoms depending on where the cancer has spread. These may include:

• Unexplained weight loss
• Enlarged lymph nodes
• Fatigue
• Fever or night sweats
• Loss of appetite
• Low red blood cell count (anemia)
• Pain or a sensation of a mass
• Changes in bowel or bladder habits
• Difficulty breathing
• Difficulty urinating
• Skin lumps or nodules
• Weakness

These symptoms can also be caused by other conditions. It is important to speak with your doctor if you experience any of them.

How Is Cancer of Unknown Primary Origin Treated?

Treatment depends on the type of cells identified in the biopsy, the extent of disease, and the patient’s overall health. Options may include chemotherapy, hormonal therapy, radiation therapy, and/or surgery. These treatments can be used individually or in combination based on your doctor’s recommendations. Important factors considered when developing a treatment plan include:

• Your age, health, and lifestyle.
• The stage or extent of your cancer.
• Any other serious health conditions you have.
• Your feelings about the need to treat cancer right away.
• Your doctor’s opinion about the urgency of treatment.
• The likelihood that treatment will help control or cure your cancer.
• Possible side effects of each treatment method.

Close communication with your doctor will help ensure that the treatment plan chosen best fits your needs.

Our Approach

We understand that a cancer diagnosis can be overwhelming and scary. Here at The New York Cancer & Blood Specialists, we build our teams around you. Our expert oncologists will help guide you through this difficult time, answering any questions you may have along the way. We are here for you and will do everything in our power to meet your specific needs and exceed your expectations. If you or a loved one is experiencing symptoms that may be related to cancer, please call us as soon as possible at (855) 528-7322 or make an appointment online.