Cancers and Specialties
We Treat
Treatments Tailored To You

Cancers and
Specialties We
Treat
Treatments
Tailored To You

Cancers of Unknown Primary

Typically, the type of cancer diagnosed is named after the area of the body in which it began, even if it later spreads elsewhere. For example, breast cancer begins in the breast, skin cancer begins in the skin, prostate cancer begins in the prostate, and so on. On rare occasions, however, the origin of cancerous cells is not immediately apparent. In those cases, a patient may be diagnosed with cancer (or carcinoma) of unknown primary, or CUP. 

Typically, cancer cells look like tissue from the part of the body where it started. A CUP diagnosis occurs when cancer cells removed from the body do not match the type of cancer cells the doctor expected to find.

 Patients who receive a CUP diagnosis will often undergo additional testing to find out the cancer’s origin, as this impacts the recommended course of treatment. If the origin is discovered, a patient’s diagnosis will change from CUP to the appropriate primary cancer type. However, sometimes the primary cancer is never found, and a diagnosis of CUP remains.

 While this can be overwhelming, know that our experts at SCRI Oncology Partners are here for you. We are here to help empower you and provide a sense of control, as well as help to ease some of the burdens associated with diagnosis and treatment.

What are some of the signs and symptoms of cancers of unknown primary (CUP)?

Since CUP is simply a cancer whose origin is unknown, the signs and symptoms can vary greatly. A patient might not observe any signs or symptoms at all. In general, we recommend checking with your doctor if you are experiencing any of the following symptoms:

 

  • Lumps or thickening anywhere in the body
  • Swollen lymph nodes 
  • Persistent pain in one part of the body 
  • Hoarseness or coughing that does not go away
  • Shortness of breath
  • Any changes in habits of the bowel or bladder
  • Unexplained or unusual bleeding or discharge
  • Persistent fever
  • Heavy night sweats
  • Unexplained loss of appetite or weight loss
  • Fatigue or weakness

Risk Factors

Staging

Treatment

Clinical Trials

How are cancers of unknown primary diagnosed?

An initial diagnosis of CUP occurs after cancer is discovered and cancer cells or tissue has been removed from the body. When a pathologist reviews this tissue and finds that it does not match the site from which it was taken, a CUP diagnosis may be given.

While all cancers include an array of testing and procedures, with CUP, the volume is typically higher. Because treatment recommendations are based on the primary cancer type, determining the origin site is a priority.

Following a biopsy, patients with CUP may also undergo one or more laboratory tests to determine the cancer type, such as a genetic analysis or a histologic study. Procedures commonly used to diagnose the primary cancer type can also include CT or CAT scans, MRI, PET scans, mammograms, endoscopy or tumor marker tests.

The area of the body in which the cancer was found can also help your physician determine which diagnostic tests to run. For instance, if the cancer was found above the diaphragm, the primary site is most likely to be in the upper part of the body.

Risk factors for cancers of unknown primary

There are few known risk factors for CUP. Risk can increase with age, with people over 60 years old being at a higher risk than younger individuals. A family history of lung, kidney or colon cancer may also be associated with a CUP diagnosis.

Types of cancers of unknown primary

There are 5 initial broad categories that CUP can be classified under at diagnosis: adenocarcinoma, poorly differentiated carcinoma, squamous cell cancer, poorly differentiated malignant neoplasm and neuroendicrine carcinoma.

Adenocarcinoma 

These cancers make up the majority (about 60%) of CUP diagnoses. They develop from gland cells and are the most common forms of lung, bowel and kidney cancers.

Poorly differentiated carcinoma 

About 30% of CUP cases fall into this category. “Poorly differentiated” means that while the cells can be classified as carcinomas, they do not have enough similarities to other cells to be classified beyond that.

Squamous cell cancer

These types of cancer cells are flat and develop in the skin, lining of the organs or the respiratory/digestive tracts.

Poorly differentiated malignant neoplasm 

Like poorly differentiated carcinomas, these cancer cells are even more irregular. Typically, the doctor is unable to determine which type of cell they began from.

Neuroendicrine carcinoma 

In some rare cases, cancer can begin in the cells of the diffuse neuroendicrine system rather than in a specific organ. These cells can be found throughout the body in various organs.

Staging

Because CUP is simply a cancer where the primary site is unknown, it does not follow a standard staging system. If testing is inconclusive, your physician will use the information available to determine the course of treatment based on the most likely type of primary cancer. Information they may consider includes:

  • Where in the body the cancer was found
  • What type of cancer cell was found
  • Whether the cancer cells are poorly differentiated
  • Which signs and symptoms the patient experiences
  • The results of laboratory tests, biopsies and procedures
  • Whether the cancer is new or recurrent

How can cancers of unknown primary be treated?

There is no standard treatment for CUP. If your physician is not able to determine the primary cancer type, treatment decisions will be guided by the information available. A patient’s general health and the extent, spread and site of the cancer all play a role in determining a treatment plan. Depending on the patient and the specific situation, treatment can vary greatly. 

 As with most cancer types, treatment will include one or more of the following:

  • Surgery
  • Radiation therapy
  • Chemotherapy
  • Hormone therapy
  • Proton therapy
  • Targeted therapy

Cancers of unknown primary clinical trials

Today’s clinical trials are tomorrow’s treatment options. A clinical trial can help determine if a treatment, drug or procedure shows a better way of treating a particular cancer or condition. At SCRI Oncology Partners we are committed to offering the latest clinical trials to improve your outcomes and ensure access to cutting-edge scientific advancements for our patients in the community.  

If you are looking for a local oncologist in Nashville, Tennessee and are interested in participating in a clinical trial for cancers of unknown primary through our collaboration with Sarah Cannon Research Institutehttps://www.scri.com/(SCRI), a global leader in oncology research, the first step is to talk to our healthcare team. 

Contact Us

Whether you are newly diagnosed, previously treated or seeking additional care or research options, we are here to support you every step of the way.

Contact Us

Whether you are newly diagnosed, previously treated or seeking additional care or research options, we are here to support you every step of the way.

Contact us

Contact Us

Whether you are newly diagnosed, previously treated or seeking additional care or research options, we are here to support you every step of the way.

Contact us