Metastatic carcinoid tumors (MCTs) are difficult not only to diagnose, but also to fully understand. Get the information you need from your primary care physician and gastroenterologist by asking these five questions.

1. What caused my MCT?

Doctors don’t know what causes carcinoid tumors. This means as far as researchers can conclude, nothing you did or didn’t do caused the tumor to grow. According to the American Cancer Society (ACS), research suggests that smoking may be a risk factor, but this hasn’t been definitively proven.

Some people are known to be at greater risk for developing a carcinoid tumor. This includes those with a family history of certain genetic disorders, such as:

  • multiple endocrine neoplasia, type I
  • neurofibromatosis type I
  • tuberous sclerosis complex
  • von Hippel Lindau disease

However, for a larger number of people with MCT, the cause is considered sporadic. This means changes in a person’s body that occurred after they were born led to the tumor growing. So a genetic disorder isn’t the cause.

2. How long could I have had the tumor?

Carcinoid tumors are very rare. Their symptoms can go misdiagnosed as other abdominal-related conditions, such as irritable bowel syndrome (IBS), for many years before a doctor correctly diagnoses the condition.

Carcinoid tumors make up less than 2 percent of all types of gastrointestinal cancers diagnosed in the United States. Their symptoms, such as chronic diarrhea, flushing, and wheezing, are nonspecific. Chronic diarrhea is a symptom also associated with IBS.

A carcinoid tumor is a type of a neuroendocrine tumor: It secretes compounds found in your neurologic and endocrine systems that can impact other functions of your body. An example compound is serotonin, an excess of which can lead to diarrhea.

When an MCT first grows, it secretes these compounds, but they empty into your liver. The liver breaks up the compounds just as it does other wastes in your body, so you don’t have any symptoms. If the tumor grows much larger or spreads to your liver, your liver can’t break down the compounds as effectively. At this point, you’ll experience additional symptoms.

On average, a person may have nonspecific symptoms for about 9.2 years before receiving an MCT diagnosis. It’s also possible the tumor could have been present for longer than that.

3. What types of medical specialists treat carcinoid tumors?

When you’re diagnosed with a carcinoid tumor, it’s possible you’ll see several types of medical specialists. They’ll work as a team to determine recommended treatments as well as monitor your condition. Here are some of the specialists who may treat your condition:

  • Endocrinologist: Because MCTs secrete endocrine compounds, you may see an endocrinologist. These doctors specialize in treating hormonal imbalances.
  • Gastroenterologist: This doctor specializes in diseases of the gastrointestinal tract, such as MCT. You may have seen a gastroenterologist when your symptoms of diarrhea first began.
  • Interventional radiologist: An interventional radiologist uses minimally invasive, image-guided procedures to treat medical conditions. This doctor can perform a procedure called a hepatic artery embolization. It cuts off blood flow to parts of your liver so an MCT can’t continue to grow.
  • Oncologist: Oncologists are specialists in treating cancers, including MCTs. They can help to identify and track the progress of your tumor as well as guide appropriate treatments.
  • Surgeon: If your tumor can be safely removed, a surgeon will be the specialist to do so. Some surgeons specialize in removing tumors, such as an oncological surgeon.

The Carcinoid Cancer Foundation maintains a list of medical specialists and centers in the United States that specialize in treating carcinoid tumors.

4. How often do people get carcinoid tumors, and who’s more at risk?

According to the ACS, doctors diagnose about 8,000 new cases of gastrointestinal carcinoid tumors in the United States each year. While the tumors are most commonly diagnosed in the gastrointestinal tract, it’s also possible to have a lung carcinoid tumor. Doctors diagnose about 4,000 new cases of lung carcinoid tumors in the United States each year, reports the ACS. This is about 1 to 2 percent of all lung cancers.

Most people diagnosed with a carcinoid tumor are in their 60s. The tumors are more common in African-Americans and women.

5. Are there new treatments on the horizon for carcinoid tumors?

Researchers are conducting studies every day on treatments for carcinoid tumors. In March 2017, the U.S. Food and Drug Administration (FDA) approved the drug telotristat ethyl (Xermelo) to treat carcinoid syndrome. The medication is intended to be taken with somatostatin therapy, such as octreotide (Sandostatin). The medication can help people who haven’t responded well to octreotide alone to experience less chronic diarrhea.

Telotristat ethyl is a pill that you can take three times a day. It lessens the amount of serotonin a carcinoid tumor produces. This can help to reduce the amount of diarrhea you experience related to a carcinoid tumor. According to the FDA, those taking telotristat ethyl in addition to somatostatin therapy for three months had an average reduction of two bowel movements a day.

Your doctor should know the latest developments in the field of MCT research. Next time you visit your doctor, ask about what other medications might be on the horizon for treating MCTs.