Carcinoid syndrome should be treated by gastro specialist

DEAR DR. ROACH » Can you please give more insight into carcinoid syndrome? In particular, I’d like to know its symptoms and how it gets diagnosed and treated? What kind of a doctor would one see with that diagnosis?

— S.B.

ANSWER » A carcinoid tumor is a type of neuroendocrine tumor of the digestive tract or lungs. In the gastrointestinal tract, these tumors are now referred to just as neuroendocrine tumors. They can produce substances that in some situations can cause carcinoid syndrome. This usually presents with flushing and diarrhea.

Symptoms are most common with carcinoid tumors of the lung or when the neuroendocrine tumor has spread. The liver normally inactivates these substances, so it is when the disease has spread to the liver that people become symptomatic. The blood from lung carcinoid tumors does not go directly to the liver, which is why lung carcinoid tumors may cause carcinoid syndrome without liver involvement. Still, more than 90% of people with carcinoid syndrome have metastatic disease — cancer that has spread to distant locations.

The diagnosis can be made by a combination of urine tests looking for the commonly produced substances, such as 5-hydroxyindoleacetic acid (5HIAA), and by anatomic tests such as scans or endoscopy.

In the past, neuroendocrine tumors were considered benign, but a better understanding of these tumors has led them to be classified as cancers and treated aggressively. Oncologists with special expertise in gastrointestinal cancers are the ideal specialists to see for treatment.

Treatment may be surgical — for example, to remove metastatic disease to the liver — or medical, such as octreotide, which inhibits release of the substances which cause flushing and diarrhea, and significantly improves symptoms in 80% or more of people with carcinoid syndrome.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.