Carcinoid Syndrome

Neuroendocrine tumors (NETs), which arise from neuroendocrine cells, can grow throughout the body but are most frequently detected in the lungs, pancreas, and digestive tract. NETs may release particular hormones or biogenic amines depending on the cell source. Neuroendocrine tumors secrete amines, polypeptides, and prostaglandins, particularly serotonin, which may cause carcinoid syndrome. The type of peptides produced by NETs is strongly correlated with the clinical characteristics of carcinoid disease. The most common organs and systems affected are the skin, GI tract, heart, and respiratory system. Testing for secreted amines and peptides in blood and/or urine is essential for diagnosing and monitoring patients with carcinoid syndrome. However, chromogranin A and other nonhormonal peptide biomarkers are less helpful in the diagnosis of carcinoid syndrome. Abdominal imaging is the initial step in radiological evaluation because NETs most frequently metastasize to the liver and cause carcinoid disease. For all patients with NETs, a multi-phasic contrast-enhanced CT scan is advised for the initial examination. In selected cases, abdominal MRI and Ga-PET are helpful. The two primary approaches that create the backbone of carcinoid syndrome treatments consist of taking measures to lessen the tumor burden and administering pharmaceuticals to stop the production of the hormones. Somatostatin, a small peptide molecule, is known as a regulatory hormone that inhibits the secretion of a wide range of other hormones. Since somatostatin receptors are expressed by about 80% of carcinoid tumors, somatostatin analogs like octreotide and lanreotide are quite helpful for managing carcinoid syndrome symptoms. Therapies targeting live metastases have increasingly become an area of interest because of the metastatic aphinity of tumor to the liver. Surgical removal of all resectable tumor tissues is the best treatment option to provide long-term remissions as well as symptomatic control among metastatic patients. Other options for those with resistant symptoms after initial treatment include telotristat and interferon. One of the most serious complications of hormone-activated carcinoid tumors is carcinoid crisis. It happens when the carcinoid syndrome symptoms are worse and additional respiratory (such as shortness of breath) and cardiovascular (such as arrhythmias and hypotension) symptoms are added. If it cannot be controlled with the right strategy, it may be life-threatening. Octreotide should be used in conjunction with symptomatic medications (antihistamines and anti-diarrheal medications) to treat carcinoid crisis.