Diagnosing Carcinoid Tumors
Because carcinoid tumors grow slowly, many are caught early, before they have had a chance to metastasize or cause symptoms. In many cases, they are found during routine tests or exams when looking for other problems.
"These tumors are often found by accident," says James Yao, MD, associate professor and deputy chair of the Department of Oncology at the University of Texas MD Anderson Cancer Center in Houston. "We may find them during a screening colonoscopy or endoscopy or because of abnormal results on a liver function test."
Sometimes the tumors are found because they are causing symptoms. If your doctor suspects a carcinoid tumor, there are a few different types of diagnostic tests to use.
- Blood and urine tests. These simple tests are often a first step in diagnosing carcinoid syndrome. Doctors use these tests to look for the excess hormones and other substances that carcinoid tumors produce.
- Imaging tests. Doctors may use imaging tests to take pictures of the inside of your body to locate tumors. These tests may include X-ray, CT scan, MRI, PET scan, or octreoscan. An octreoscan is especially helpful in finding carcinoid tumors. During the test, a small amount of radioactive material and a hormone-like substance that is attracted to carcinoid tumors are injected into the bloodstream. A few hours later, a special camera looks for any "hotspots" where these substances have collected.
- Endoscopy. This is a type of test that uses a long flexible tube with a camera or ultrasound at the end to look for gastrointestinal tumors. Using various kinds of endoscopy, doctors can see almost all areas of the digestive tract, from the esophagus to the rectum.
- Biopsy. Once the tumor has been found, your doctor may take a small piece of tissue from the tumor to look at it under a microscope. "A biopsy is essential in diagnosing carcinoid tumor," says Warner. "Until you examine the cells under a microscope you don't know for certain what type of tumor you're dealing with. It also helps us know what type of treatments the tumor will best respond to."
Prognosis When You Have Carcinoid Tumors
When carcinoid tumors are caught before they have spread, they can often be completely removed and cured by surgery. Once the tumors have spread to other areas, other types of treatments may also be used, either on their own or in combination with surgery. These treatments may include medication, chemotherapy, radiation therapy, and ablation, to destroy all or part of the tumor.
No matter when the tumors are found, the prognosis is better the earlier treatment is started. "Some doctors used think that because these tumors were so slow growing that it was better to wait until the tumors were causing problems to treat them," says Warner. "But we now know that surgery and other treatments work much better when done early. Early, aggressive treatment of carcinoid tumors leads to a much better outcome for patients."