Neuroendocrine tumors (NETs) are a type of cancer that affect the neuroendocrine system, which is a combination of nerve and hormone cells. NETs most commonly occur in the gastrointestinal (GI) tract, but can also affect other organs such as the pancreas, lungs, and thymus. While NETs can occur anywhere, they are most commonly found in the small intestine, rectum, and appendix.
NETs in the Gastrointestinal Tract
NETs in the GI tract are the most common types of NETs, accounting for more than 75 percent of all cases. They are usually slow-growing and can be divided into two main types: carcinoid tumors and small cell carcinomas. Carcinoid tumors are the most common type of NETs and usually develop in the stomach, small intestine, or rectum. Small cell carcinomas are more aggressive and typically develop in the colon or rectum.
NETs in Other Organs
NETs can also occur in other organs, including the pancreas, lungs, thymus, and thyroid. Pancreatic NETs are the second most common type of NETs, accounting for approximately 10 percent of all cases. These tumors can occur in the head, body, or tail of the pancreas and can be either benign or malignant. NETs of the lungs, thymus, and thyroid are less common but can still occur.
Risk Factors for NETs
NETs can occur in anyone, but there are certain factors that can increase a person’s risk. These include age, family history, certain genetic conditions, and certain lifestyle factors such as smoking and alcohol consumption. People with certain medical conditions such as diabetes, Crohn’s disease, or ulcerative colitis are also at an increased risk for developing NETs.
Diagnosis and Treatment of NETs
NETs are usually diagnosed using imaging tests such as CT scans or MRI scans. If the tumor is malignant, a biopsy may be performed to confirm the diagnosis. Treatment for NETs depends on the size and location of the tumor as well as the patient’s overall health. Common treatments include surgery, radiation therapy, and chemotherapy.