Diagnosing Neuroendocrine Tumors (NETs)

About Neuroendocrine Tumors (NETs)

At Penn Medicine, patients with neuroendocrine tumors receive their care from a multidisciplinary team of nationally recognized experts in the diagnosis, treatment and research of cancer.

Penn's Neuroendocrine Tumor Program treats the following:

  • Gastroenteropancreatic neuroendocrine tumors (GEP-NETs)
    • Alimentary tract (carcinoid tumors)
    • Pancreatic endocrine tumors (PETs)
  • Pheochromocytomas/paragangliomas (PHEOs)
  • Other neuroendocrine tumors (NETs)

Penn Medicine offers one of the only dedicated NET programs in the country with the combined expertise to treat both GEP-NETs and PHEOs. In addition, Penn's program is the first and only one of its kind in the mid-Atlantic region.

Penn Medicine's multidisciplinary approach to cancer diagnosis and treatment provides better outcomes and gives patients access to the most advanced treatment, surgical techniques and clinical trials.

Because navigating a cancer diagnosis and treatment options can be difficult, patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse, who can help them make an appointment with the right physician.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN (7366).

About Neuroendocrine Tumors

Neuroendocrine tumors (NETs) form from cells that release hormones in response to a signal from the nervous system. Some examples of neuroendocrine tumors are carcinoid tumors, islet cell tumors, phechromocytomas and Merkel cell cancers.

Neuroendocrine tumors are often small and can be malignant (cancerous) or benign (non-cancerous). Carcinoid tumors most commonly develop in the gastrointestinal tract including the esophagus, stomach, small intestine, appendix and colon. Rarely, carcinoid tumors occur in the lungs and bronchial tissue. Pancreatic neuroendocrine tumors (PETs) typically develop in the pancreas and duodenum.

Not all NETs cause symptoms. However, because they originate from hormone producing tissues, the symptoms they cause can be linked to the release of various hormones into the blood stream causing:

  • Facial flushing
  • Diarrhea
  • Shortness of breath
  • Abdominal pain
  • Low blood sugar
  • Wheezing
  • A feeling of abdominal fullness

Read more About Neuroendocrine Tumors (NETs)

Diagnosing Neuroendocrine Tumors (NETs)

An accurate diagnosis from trusted tumor specialists is the first step in getting personalized treatment options to treat neuroendocrine tumors.

Patients who choose Penn Medicine, benefit from a multidisciplinary team of cancer and tumor specialists including gastroenterologists, radiologists, pathologists and surgeons who work together to provide a diagnosis and treatment plan designed specifically for each patient with neuroendocrine tumors.

Cancer specialists at Penn Medicine are highly experienced in using the most advanced techniques for diagnosing cancer and are actively researching better and more precise ways to detect neuroendocrine tumors.

Navigating a cancer diagnosis and treatment options can be difficult, patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse, who can help them make an appointment with the right person. Penn Medicine’s contact center has experienced cancer nurses available and ready to guide patients in finding the cancer specialist right for them.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN (7366).

Diagnostic Tools for Neuroendocrine Tumors

Penn Medicine’s multidisciplinary treatment team includes nationally recognized pathologists and radiologists who are experts at finding and diagnosing tumors.
After a thorough medical exam, if a physician suspects a patient may have a NET, he might order one or more of these diagnostic tests:

  • Blood/urine tests. Blood and urine samples may indicate abnormal levels of hormones and other substances. Specific tests are available to identify both carcinoid and pheochromocytomas.
  • Imaging tests. Pictures of the inside of the body can help find out whether a suspicious area might be cancerous, learn how far cancer may have spread, and to help determine if treatment is working.
    • Computed tomography (CT) scan. A CT scan creates a 3-D X-ray of the inside of the body. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan is used to see if the tumor has spread to the liver and to detect a carcinoid tumor in lymph nodes within the abdomen. Sometimes, a contrast medium (dye) is used to provide better detail.
    • Magnetic resonance imaging (MRI). An MRI uses magnetic fields to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture.
    • Radionuclide scanning (OctreoScan). A small amount of a radioactive hormone-like substance that is attracted to neuroendocrine tumors is injected into a vein. A special camera is then used to show where the radioactivity accumulates.
    • MIBG scan. An imaging test that uses a radioactive substance (called a tracer) and a special scanner to find or confirm the presence of pheochromocytoma and neuroblastoma, which are tumors of specific types of nervous tissue.
    • Endoscopy. Endoscopy allows the doctor to see the lining of the upper or lower digestive system with a thin, lighted, flexible tube called an endoscope. A patient may be sedated as the tube is inserted through the mouth, down the esophagus, into the stomach and small bowel, or through the anus into the rectum. If an abnormality is found, a fine needle aspiration biopsy may be performed.
    • Endoscopic ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. This procedure is often done at the same time as the upper endoscopy. The endoscopic ultrasound can show enlarged lymph nodes, which may indicate a tumor or advanced disease. If identified, a fine needle aspiration biopsy may be performed.
    • Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected a vein. It collects in areas of the bone and is detected by a special camera.
    • Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body. The tumor absorbs the radioactive substance, and a scanner detects this substance to produce images.
    • Barium imaging. Barium coats the lining of the esophagus, stomach, and intestines, so abnormalities are easier to see on X-rays. If there is an abnormality, an endoscopic biopsy can help make the diagnosis of cancer. Barium may be given through a swallow test or an enema.
  • Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. A pathologist, who is a doctor that specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease, analyzes the tissue. A biopsy can tell a pathologist the grade and differentiation of the tumor.

Staging Neuroendocrine Tumors

Staging is a way of describing a tumor: Where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the tumor’s stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's chance of recovery.

Physicians at Penn Medicine use the TNM staging system.

T Stage

The T stage represents the extent of the primary tumor itself.

  • TX: Primary tumor cannot be assessed
  • T0: No evidence of primary tumor
  • T1-4: Increasing degrees of size, number or invasion of the primary tumor.

N Stage

The N stage represents the degree of the involvement of the lymph nodes.

  • NX: The regional lymph nodes cannot be assessed
  • N0: No evidence of spread to the lymph node
  • N1: Regional lymph nodes are involved with tumor

M Stage

The M stage represents whether or not there is spread of cancer to other parts of the body.

  • M0: No evidence of distant spread of the cancer
  • M1: Evidence of distant spread of the cancer including spread to non-regional lymph node chains

The “staging diagnosis” combines the T, N and M groups into four stages (Stage I-IV); some of which have subtypes (a or b) according to overall tumor burden.

Cancer specialists at Penn often classify tumors by whether or not they can be resected, or removed with surgery. There are three ways physicians look at tumors:

  • Localized resectable tumors: These are tumors that can be completely removed by surgery. This would include most stage I and some stage II cancers in the TNM system.
  • Localized unresectable tumors: Cancers that have not spread to the lymph nodes or distant organs, but cannot be completely removed by surgery are classified as localized unresectable. This would include some early stage cancers, as well as stage IIIA and IIIB cancers in the TNM system. For NETs, debulking, removing some of all of the tumor, surgery may still be an option.
  • Advanced tumors: Cancers that have spread to lymph nodes or other organs, especially the liver, are classified as advanced. These would include stage IIIC and stage IV cancers in the TNM system. Most advanced tumors cannot be cured with surgery, though debulking surgery may be done to improve overall outcome.

Neuroendocrine Tumor (NET) Treatment

Penn Medicine offers one of the only dedicated neuroendocrine tumor (NET) programs in the country with the combined expertise to treat both gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and pheochromocytomas and paragangliomas (PHEOs). In addition, Penn Medicine’s program is the first and only one of its kind in the region.

Following the diagnosis and staging of neuroendocrine tumors, cancer specialists at Penn’s Abramson Cancer Center develop a personalized treatment plan. Penn’s treatment options for neuroendocrine tumors include:

  • Surgery
    • Local and local-regional excision
    • Debulking surgery, including liver resection
    • Radiofrequency ablation
    • Liver transplantation
  • Chemotherapy and biologic therapies
    • Hormone therapy
      • Octreotide
      • Proton pump inhibitors (PPIs)
    • Liver-directed therapies
      • Ethanol injection
      • Chemoembolization of the hepatic artery
    • Chemotherapy
    • Targeted therapy
  • External-beam radiation therapy
  • Clinical trials
  • Other treatments
    • Integrative medicine and wellness
    • Palliative care
    • Penn Home Care and Hospice

Because navigating a cancer diagnosis and its treatment options can be difficult, patients who wish to connect with a cancer specialist at Penn Medicine can speak with a cancer nurse, who can assist in making an appointment with the right physician.

To connect with a cancer nurse at Penn Medicine, patients should call 800-789-PENN.

Read more Neuroendocrine Tumor (NET) Treatment

Neuroendocrine Tumor Survivorship

Patients with neuroendocrine tumors may require more follow-up care than other patients.

Some neuroendocrine tumor patients may require follow-up treatment using biotherapies, or other medications. Others may require more frequent imaging tests. Patients at Penn Medicine receive a personalized survivorship care plan that addresses all issues from follow-up care to the physical, emotional and financial complications that can occur long after their therapy is complete.

Survivorship programs at Penn Medicine are a distinct phase of neuroendocrine tumor care and are designed to help patients' transition from treatment to a post-treatment lifestyle.

Read more Neuroendocrine Tumor (NET) Survivorship

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