Carcinoid cancer is a type of neuroendocrine cancer that occurs when neuroendocrine cells grow out of control. Carcinoid tumors are rare and usually slow-growing tumors. Neuroendocrine cells produce hormones that control metabolism, digestion, and other bodily functions.
In adults, carcinoid cancer tends to start in parts of the digestive tract, such as the stomach, small intestine, appendix, colon, and rectum. In children and young adults, carcinoid cancer often starts in the appendix or in the lungs.
Carcinoid tumors may also be found in the pancreas or liver.
Types of carcinoid tumors include:
- Slow-growing tumors
- Most common type
- Usually remain small, under about an inch wide
- Don’t spread to other parts of the body
- Faster-growing tumors
- Hormone-secreting tumors
What Are Symptoms of Carcinoid Cancer?
Many people with carcinoid tumors do not have symptoms. Symptoms of carcinoid tumor depend on where the tumor is located and whether it is producing hormones (carcinoid syndrome).
Symptoms of a carcinoid tumor in the digestive tract may include:
- Abdominal pain or pressure
- Nausea
- Vomiting
- Diarrhea
- Change in bowel habits
- Blood in stool
- Weight loss
- Symptoms of appendicitis, such as pain in the abdomen (if the cancer is in the appendix)
Symptoms of a carcinoid tumor in the lungs may include:
- Trouble breathing
- Chest pain
- Wheezing
- Cough/coughing up blood
Symptoms of a carcinoid tumor in the lungs may be mistakenly diagnosed as pneumonia.
About 40% of people with carcinoid cancer will experience carcinoid syndrome (also called carcinoid crisis). Symptoms of carcinoid syndrome can include:
- Flushing
- Rapid heartbeat
- Abdominal cramps
- Watery diarrhea
- Skin rash
- Spider veins (telangiectasias), usually on the nose, cheek, or upper lip
- Trouble breathing/shortness of breath
- Wheezing
- Carcinoid heart disease, which affects the heart valves
- May not always cause symptoms
- When symptoms of carcinoid heart disease occur, they may include:
- Fluid in the abdomen (ascites) and fluid in the feet (swelling or edema)
- Trouble breathing/shortness of breath
- Tiredness/fatigue
- Low blood pressure
- Heart murmur
Symptoms of carcinoid syndrome may be triggered by exercise, stress, and certain foods or drinks, such as alcohol (especially red wine), chocolate, and some cheeses.
How Is Carcinoid Cancer Diagnosed?
Carcinoid cancer is diagnosed with a patient history and physical examination, along with tests such as:
- Blood tests
- Serotonin
- Chromogranin A (CgA)
- Urine tests
- 5-HIAA (5-hydroxy indole acetic acid)
- Imaging tests
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI) scan
- Positron emission tomography (PET) scan
- Chest X-ray
- OctreoScan
- Biopsy
What Is the Treatment for Carcinoid Cancer?
Treatment for carcinoid cancer depends on the symptoms, where the tumor is located, and how much the cancer has spread.
Treatment for carcinoid cancer may include one or more of the following:
- Surgery
- Removal or destruction of large portions of the tumor (debulking)
- Cryoablation (freezing) or radiofrequency ablation (RFA)
- Chemoembolization
- Somatostatin analogs
- Octreotide/lanreotide and vapreotide (Sandostatin, Sandostatin LAR)
- Targeted therapy
- Peptide receptor radionuclide therapy (PRRT)
- Chemotherapy, usually involves more than one drug in combination
- Leucovorin-fluorouracil and streptozotocin
- Cytoxan-doxorubicin and cisplatin
- Dacarbazine-fluorouracil
- Etoposide-cisplatin
- Treatments under investigation: everolimus (Afinitor), sorafenib (Nexavar), sunitinib (Sutent), atiprimod, pasireotide (SOM230), bevacizumab (Avastin), temozolomide (Temodar), and capecitabine (Xeloda)
- Radiotherapy
- Supportive treatment
- High protein diet
- Vitamin supplements, particularly niacin and mineral supplements (such as potassium, magnesium, calcium, iron, and even salt)
- Anti-diarrheal medications
- Cyproheptadine (Periactin) to relieve flushing and diarrhea
- Antihistamines and alpha-adrenergic blocking drugs to prevent carcinoid syndrome attacks
- Corticosteroids may be used for certain very severe and prolonged carcinoid crises associated with bronchial (lung) carcinoids or some carcinoids of the stomach
- Freshly grated nutmeg (1 teaspoon, 3 times a day) may help control diarrhea
- Black raspberry extract may have carcinoid inhibiting properties
- Avoid things that can trigger carcinoid crisis attacks
- Alcoholic beverages
- Physical and emotional stress
- Adrenaline-like drugs including certain asthma inhalers, nasal decongestants, and adrenaline itself
From 
https://www.cancer.gov/pediatric-adult-rare-tumor/rare-tumors/rare-endocrine-tumor/carcinoid-tumor
https://www.carcinoid.org/
https://www.hopkinsmedicine.org/health/conditions-and-diseases/carcinoid-tumor
https://www.uptodate.com/contents/carcinoid-syndrome-the-basics?search=carcinoid%20syndrome&source=search_result&selectedTitle=1~78&usage_type=default&display_rank=1
https://www.nhsinform.scot/illnesses-and-conditions/cancer/cancer-types-in-adults/carcinoid-syndrome-and-carcinoid-tumours