Carcinoid syndrome: causes, symptoms and treatment

Carcinoid or carcinoid syndrome refers to a set of signs and symptoms that may appear as a complication of certain tumors. They are called carcinoid tumors, capable of secreting chemicals such as serotonin.

Although they are not the most common type of cancer, these tumors and the carcinoid syndrome can be very aggressive. Many people experience shortness of breath or rapid heartbeat. In this article we explain everything you need to know and how the disorder is treated.

What is carcinoid syndrome?

Carcinoid syndrome is a set of signs and symptoms that are due to the action of certain substances released by a tumor. According to an article published in the Medical Journal of Costa Rica and Central America, most carcinoid tumors they develop from neuroendocrine cells in the digestive tract.

In fact, it is estimated that around 50% of all small intestine cancers are of this type. However, they can also appear in the lung, pancreas, and liver. The truth is that carcinoid syndrome only affects around 8% of people who have these tumors.

It is more common when there are extensive metastases in the liver. The tumor releases substances such as serotonin, histamine, and prostaglandins. All of them can act on many parts of the body and produce the characteristic symptoms.

Symptoms of carcinoid syndrome

As explained by specialists from the Mayo Clinic, one of the most frequent symptoms is redness of the skin. It usually affects the face and the upper part of the chest. This is because many of the chemicals mentioned cause vasodilation.

The redness appears abruptly and lasts between minutes and hours. Sometimes it is triggered by certain agents that also cause vasodilation, such as exercise or alcohol. It is accompanied by hypotension, dizziness, and fatigue.

Another common symptom is diarrhea. Especially when the tumor releases serotonin, since it acts on intestinal motility. Stools are often watery and abdominal cramps may appear.

Carcinoid syndrome also features tachycardia and shortness of breath. It is similar to an anxiety attack. Some people experience decreased sex drive, heart murmurs, and added breath sounds.

Diarrhea from carcinoid syndrome is caused by the excessive release of serotonin that affects intestinal motility.

Possible complications

Carcinoid syndrome can lead to numerous complications. According to a study published in the Chilean Journal of Cardiology, one of the most relevant is carcinoid heart disease. It occurs because plaques of fibrous tissue form on the valves of the heart.

Specifically, the most affected areas are the right heart valves (tricuspid and pulmonary). This causes heart failure to develop over time..

Another very important complication is carcinoid crisis. It is when the syndrome is aggravated by a trigger and the symptoms intensify. For example, when anesthetics are used for surgery. Blood pressure can drop too low and lead to shock mortal.

Intestinal obstruction is also considered one of the complications of carcinoid syndrome. However, it tends to be a consequence of the tumor itself. When it reaches a significant size or extends to the lymph nodes, the intestinal loops may rotate on themselves.

What Causes Carcinoid Syndrome?

The signs and symptoms that characterize carcinoid syndrome as such are derived from the chemicals produced by the tumor. They are the ones we have mentioned before: serotonin, histamine, prostaglandins.

The explanation for why the carcinoid syndrome does not occur in all tumors is that the liver usually neutralizes these chemical agents before they produce their action. Nevertheless, in cases where there are many liver metastases, the organ is damaged.

Risk factors for suffering it

The main risk factor for having a carcinoid syndrome is clearly having a carcinoid tumor. In turn, there are circumstances that can increase the probability of suffering from this type of cancer.

The main indicator is having a family history of the same type of tumor. Also if there are cases in the family of multiple endocrine neoplasia 1 or neurofibromatosis type 1.

As carcinoid tumors usually develop in the digestive tract, it is important to note that there are certain aspects that can lead to their appearance. Pernicious anemia or atrophic gastritis are some of them.

How is it diagnosed?

Carcinoid syndrome is usually diagnosed through symptoms. It is essential that the patient explains all the details to the doctor. In addition, the existence of an underlying tumor may already be known.

Nevertheless, in some cases the carcinoid syndrome is the first manifestation of cancer. That is why it is important to carry out a series of complementary tests to confirm. Blood and urine tests are very helpful. They allow you to see if any substance is above its usual concentration.

Magnetic resonance imaging and computed tomography analyze the existence of a tumor and where it is. There are others, such as PET-CT, that help locate metastases.

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Treatment of carcinoid syndrome

Imaging studies are used to locate the tumor causing the syndrome.

In order to address the carcinoid syndrome, it is essential to treat the underlying cancer. A study published in Endocrinology and Nutrition explains what types of therapies are currently available. They vary depending on the characteristics of the tumor and, above all, on the presence of metastases.

One option is surgery to try to remove part or all of the tumor. In addition, biological drugs, such as interferon alpha, are frequently used. These stimulate the immune system to fight cancer.

Hepatic artery embolization can also be used if there are metastases in the liver. In this way, the main blood flow to the organ is cut off and the tumor cannot grow. Chemotherapy can also be helpful, as can radiofrequency ablation.

Importantly, there are numerous medications that can be used to relieve the symptoms of carcinoid syndrome as such. For example, octreotide and lanreotide, which are analogues of a substance important to the digestive system call somatostatin. They can reduce diarrhea and redness.

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Carcinoid syndrome derives from a tumor

It is important to emphasize again that carcinoid syndrome is produced by the action of substances generated by a carcinoid tumor. They are tumors that, in most cases, develop in the digestive tract. However, they can also appear in the lung or metastasize to the liver.

It is essential to recognize the symptoms of this syndrome, such as hot flashes, shortness of breath, and tachycardias. When they appear, it is always necessary to rule out that it is a neoplasm.