Carcinoid tumors (also called as neuro-endocrine tumors or APUDOMAS) are the tumors which can develop in any age for no obvious reason. At present nothing is known about cause of these tumors. They do not develop as a result of toxic injury, infections or drugs and there is no obvious association with any particular lifestyle. Possible causes include mutations of genes. The primary tumor often develops in the small bowel (small intestine) or appendix but it can occur in many other body part such as the lung, pancreas, large bowel, ovary or testis.
Quiet often the primary tumor is too small and remains hidden and finding and removing the original primary tumor may not necessarily help once metastases (secondary tumors) have occurred. Sometimes the primary tumor is diagnosed early and is removed without any spread, but frequently it is only diagnosed once it has spread to the liver.
Diagnoses of neuroendocrine (carcinoid) tumors:
Clinical evaluation by the doctor to look for the presence of symptoms and presence of any lumps in the tummy. These tumors are usually diagnosed with the help of scans (ultrasound, CT, MRI) and blood or urine tests.
24-hour urine collections (passing water into a large bottle for 24 hours) and some special blood samples will often detect whether any hormones are being produced by the tumor.
Other methods for finding the primary site may include CT scans of the chest, barium studies of the small bowel, or colonoscopy. A colonoscopy is a procedure to examine the large bowel (colon) and is carried out with camera guided tube called a colonoscope. This is a flexible tube about the width of an index finger with a light and a camera in its tip.
Blood tests are repeated to monitor the progress of this disease. One of the tests that has recently appeared is the Chromogranin A level (a chemical measured in the blood). Repeated tests for this chemical may tell us whether the tumor is growing or moving to other areas of the body.
Histology/cytology: All of the previously mentioned tests may lead the doctor to diagnose the carcinoid cancer. However the only definite way to confirm this diagnosis is to examine some of the abnormal tissue (cancer cells) under a microscope. A tissue sample is taken by performing a biopsy. This is when a needle is passed through your skin, into the affected area. If your doctor is planning to treat your cancer with surgery, you may not undergo a biopsy, as tissue confirmation can be obtained after the operation, by the laboratory.
Depending on the tumor, the original biopsy (tissue sample taken with a needle or taken during surgery) can be reexamined and stained, using a chemical called MIB-1 stain (or ki67) and this can give an idea of how aggressive the tumor is likely to be in the future.
Many different treatment options are available to you, including doing nothing. It is important to know that some patients will be symptom-free for many years without any treatment. Treatment options include:
Pain medications: simple pain relief, as and when required.
Octreotide injections: These are normally given once every two or four weeks. These are more convenient than the twice or thrice daily injections.
Hepatic artery embolization (TAE): This is a procedure done in the x-ray department where a catheter is passed into an artery in your leg and threaded up into your liver. A substance is then injected in order to block the main artery to the liver. This is very effective but can cause pain and produce fevers for some days after the procedure. Occasionally there can be more serious side effects such as liver failure or abscess formation.
Trans-arterial chemo-embolisation (TACE): TACE (or chemoembolisation) is sometimes given through the catheter at the same time as the embolisation.
Trans-arterial radio-embolization (TARE): TARE in exactly the same as TACE and with the same aim, but with radioactive isotope (small radiation emitting particle) instead of chemotherapy drug. It will be offered to the patients if it is not appropriate to use a chemotherapy drug. Other more invasive treatments include surgery on the liver (removing one or more secondary tumors from the liver), removing the primary site by surgery and liver transplantation.
Chemotherapy: with intravenous drugs, is a further option and can be effective in certain types of tumor. Side effects of chemotherapy are often nausea, vomiting, skin rashes, and diarrhea. Some, but not all, types will cause hair loss. In general, pancreatic tumors seem rather more responsive to chemotherapy than those arising from the small bowel or ileum. More experimental treatments are currently being developed. They are forms of targeted radiotherapy (delivering high doses of radiation to the tumors by the “magic bullet principal”). These may be referred to as MIBG therapy, Indium or Yttrium-octreotide therapy. These work by delivering a dose of radiation to the body which can result in temporary damage to the bone marrow. You will need to have regular blood tests to monitor this. The radiation may also affect your kidneys and occasionally it can cause infertility.
Radiofrequency ablation (RFA): is a form of treatment that consists of putting needles or probes through the skin directly into the tumor and passing some radiation through the tumor. This is done under local or general anesthetic.
Alcohol ablation: has also been injected into these tumors with a needle through the skin and this can reduce the size of the tumor in some cases.