Gastrointestinal carcinoid tumor

A gastro-intestinal carcinoid tumor is an uncommon type of cancer that develops in the lining of the digestive tract. When cells start to multiply uncontrollably, cancer develops. to gain a deeper understanding of what cancer is and how it develops and spreads.

Knowing about the gastrointestinal system and the neuroendocrine system is helpful in understanding gastrointestinal carcinoid tumors.

Slow-growing cancers called carcinoid tumors can develop in many locations throughout your body. The digestive tract (stomach, appendix, small intestine, colon, or rectum) or the lungs is where carcinoid tumors, a subset of neuroendocrine tumors, typically develop.

Early signs and symptoms of carcinoid tumors are frequently absent. Hormones that induce signs and symptoms like diarrhea or skin flushing can be produced and released by carcinoid tumors into the body. Surgery and medication are frequently used in the management of carcinoid tumors.

The majority of GI carcinoids develop slowly. They typically produce ambiguous symptoms, if any at all. Doctors and patients are prone to looking into other, more widespread potential reasons first when trying to find out what’s going on. Such circumstances may put off a diagnosis for months or even years. However, some do exhibit symptoms that help with diagnosis.

Symptoms by tumor location

The symptoms a person can have from a GI carcinoid tumor often depend on where it is growing.

Appendix

Frequently, people with appendix tumors don’t exhibit any symptoms. When the appendix is removed to treat another issue, this is typically when the tumor is found. Appendicitis can occasionally result from a tumor blocking the passageway between the appendix and the rest of the intestine. As a result, symptoms like fever, nausea, vomiting, and abdominal pain develop.

Small intestine or colon

The intestines may kink and become temporarily clogged if the tumor begins in the small intestine. As a result, you can experience intermittent cramps, stomach pain, exhaustion, bloating, diarrhea, nausea, and vomiting.

Before a carcinoid tumor is discovered, these symptoms may occasionally persist for years. Before a tumor entirely stops (obstructs) the intestine, causing severe abdominal pain, nausea, and vomiting, as well as a potentially life-threatening scenario, it typically has to grow huge.

The common bile duct (from the liver) and the pancreatic duct (from the pancreas) flow into the intestine through the aperture of the ampulla of Vater, which is occasionally blocked by a carcinoid tumour. Bile can back up when this passageway is obstructed, which can cause the skin and eyes to turn yellow (jaundice). Pancreatitis, which can result in an inflamed pancreas and cause stomach pain, nausea, and vomiting, can also be brought on by a buildup of pancreatic secretions.

Intestinal hemorrhage can occasionally result from a carcinoid tumor. Anemia (insufficient red blood cells) accompanying weariness and breathlessness might result from this.

The rectum

Rectal carcinoid tumors are often found during routine exams, even though they can cause pain and bleeding from the rectum and constipation.

The stomach

Carcinoid tumors that develop in the stomach usually grow slowly and often do not cause symptoms. They are sometimes found when the stomach is examined by an endoscopy looking for other things. Some can cause symptoms such as carcinoid syndrome.

Hormones made by carcinoid tumors

Some carcinoid tumors can release hormones into the bloodstream. This process can cause different symptoms depending on which hormones are released.

Carcinoid syndrome

About 1 out of 10 carcinoid tumors release enough hormone-like substances into the bloodstream to cause carcinoid syndrome symptoms. These include:

• Facial flushing (redness and warm feeling)
• Severe diarrhea
• Wheezing
• Fast heartbeat

Cushing syndrome

Some carcinoid tumors produce ACTH (adrenocorticotropic hormone), a substance that causes the adrenal glands to make too much cortisol (a steroid). This can cause Cushing syndrome, with symptoms of:

• Weight gain
• Muscle weakness
• High blood sugar (even diabetes)
• High blood pressure
• Increased body and facial hair
• A bulge of fat on the back of the neck
• Skin changes like stretch marks (called striae)

Zollinger – Ellison syndrome

Gastrin, a hormone produced by carcinoid tumors, tells the stomach to produce acid. Zollinger-Ellison syndrome, in which the stomach produces excessive acid, can be brought on by taking too much gastrin. High levels of acid can induce stomach lining irritation and even stomach ulcers, which can be painful, nauseating, and cause loss of appetite.

Extreme ulcers may begin bleeding. If the bleeding is minor, it may result in anemia (lack of red blood cells), which can cause symptoms like exhaustion and shortness of breath. Stools may become dark and tarry if the bleeding is more severe. Life-threatening bleeding can occur.

If stomach acid gets into the small intestine, it can harm the lining of the intestine and destroy digestive enzymes before they can accomplish their job of breaking down food. Weight loss and diarrhea may result from this.

Diagnosing gastrointestinal carcinoid tumors

Tests and procedures used to diagnose carcinoid tumors include:

• Blood tests: If you have a carcinoid tumor, your blood may contain high levels of hormones secreted by a carcinoid tumor or byproducts created when those hormones are broken down by the body.
• Urine tests: People with carcinoid tumors have excess levels of a chemical in their urine that’s produced when the body breaks down hormones secreted by carcinoid tumors.
• Imaging tests: Imaging tests, including a computerized tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET), X-ray, and nuclear medicine scans, may help your doctor pinpoint the carcinoid tumor’s location.
• A scope or camera that sees inside your body: Your doctor may use a long, thin tube equipped with a lens or camera to examine areas inside your body. An endoscopy, which involves passing a scope down your throat, may help your doctor see inside your gastrointestinal tract. A bronchoscopy, using a scope passed down your throat and into your lungs, can help find lung carcinoid tumors. Passing a scope through your rectum (colonoscopy) can help diagnose rectal carcinoid tumors. To see inside your small intestine, your doctor may recommend a test using a pill-sized camera that you swallow (capsule endoscopy).
• Removing tissue for laboratory testing: A sample of tissue from the tumor (biopsy) may be collected to confirm your diagnosis. The type of biopsy you’ll undergo depends on where your tumor is located. One way of collecting a tissue sample involves using a needle to draw cells out of the tumor. Another option may be through surgery. The tissue is sent to a laboratory for testing to determine the types of cells in the tumor and how aggressive those cells appear under the microscope.

Treatment of gastrointestinal carcinoid tumor

Your treatment for a carcinoid tumor will be influenced by the tumor’s location, whether the cancer has spread to other body parts, the types of hormones the tumor secretes, your general health, and your personal preferences.

Treatment options may include:

Surgery: When detected early, a carcinoid tumor may be removed completely using surgery. If carcinoid tumors are advanced when discovered, complete removal may not be possible. In some situations, surgeons may try to remove as much of the tumor as possible to help control signs and symptoms.

Medications: The signs and symptoms of carcinoid syndrome may be lessened, and tumor growth may be slowed, by taking drugs that block hormones generated by the tumor.

Injections under the skin are used to provide octreotide (Sandostatin, Bynfezia Pen) and lanreotide (Somatuline Depot). Abdominal pain, bloating, and diarrhea are possible side effects from either medicine. To further try to alleviate the symptoms of carcinoid syndrome, the medication telotristat (Xermelo) is occasionally used with octreotide or lanreotide.

Chemotherapy: Strong medicines are used in chemotherapy to kill tumor cells. It can be administered intravenously or as a tablet. When surgery cannot be used to remove advanced carcinoid tumors, chemotherapy may be advised.

Targeted therapy: Targeted therapies concentrate on particular aberrations found in tumor cells. Targeted medication therapies can kill tumor cells by preventing these aberrations. For advanced carcinoid tumors, chemotherapy is frequently coupled with targeted medication therapy.

Drugs that deliver radiation directly to cancer cells:  In peptide receptor radionuclide therapy (PRRT), cancer cells are killed by radioactivity and are targeted by a medication. The medicine is injected into your body during PRRT for carcinoid tumors, where it travels to the cancer cells, attaches to them, and then delivers the radiation to them. For those with advanced carcinoid tumors, this therapy might be a possibility.

Treatment when cancer spreads to the liver: Hepatic metastases from carcinoid tumors are frequent. Possible treatments include surgery to remove a portion of the liver, hepatic artery embolization, and the use of heat and cold to kill cancer cells. The liver’s carcinoid tumor cells are killed by radiofrequency ablation’s heat treatments. Cryoablation destroys cancer cells by repeatedly freezing and thawing them.

CAR T-Cell therapy for gastric carcinoid tumors

A recently created immunotherapy for the treatment of tumors is called chimeric antigen receptor-engineered T-cell (CAR-T) therapy. Researchers have investigated its use in treating solid tumors, such as gastric cancer, because CAR-T therapy has shown remarkable efficacy in treating CD19-positive hematological malignancies.