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Gastrointestinal neuroendocrine tumours and carcinomas

Gastrointestinal (GI)Gastrointestinal (GI)Referring to or having to do with the digestive organs, particularly the stomach, small intestine and large intestine. neuroendocrine tumours or carcinomas are rare, slow-growing tumours that develop in diffuse neuroendocrine cells in the digestive system. They were all called carcinoid tumours until the World Health Organization (WHO) revised the terminology in 2000.

Most people with GI neuroendocrine tumours or carcinomas do not have any identifiable risk factors. Rarely, they may develop from inherited or genetic conditions, such as in multiple endocrine neoplasia (MEN) syndromes.

Recognizing symptoms and getting regular checkups are the best ways to detect GI neuroendocrine tumours or carcinomas early. The sooner symptoms are reported, the sooner a doctor can diagnose and treat the cancer.

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Signs and symptoms

GI neuroendocrine tumours cause a variety of different signs and symptoms. Most are slow-growing and symptoms result from the growth of the tumour and the effects of specific hormones it produces. Many neuroendocrine tumours are small and non-functional (do not produce hormones), causing no symptoms at all.

Other health conditions can have the same signs and symptoms as GI neuroendocrine tumours, so having any of the following symptoms does not necessarily mean a person has cancer. However, it is important to see a doctor about:

Symptoms caused by tumour growth

  • abdominal pain or discomfort
  • bloating
  • nausea or vomiting
  • constipation
  • weight loss
  • bowel obstruction
  • jaundice
  • blood in the stool

Symptoms caused by hormone production

  • flushing
  • diarrhea
  • wheezing
  • palpitations

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Pathology and staging

All GI neuroendocrine tumours or carcinomas were called carcinoids until the World Health Organization (WHO) reviewed the terminology and classification in 2000. They are now divided into:

  • neuroendocrine tumours
  • well-differentiated neuroendocrine carcinoma
  • poorly differentiated neuroendocrine carcinoma

The term neuroendocrine tumour applies to abnormal growths that develop in neuroendocrine cells. They are benign or their potential to spread (metastasize) to other parts of the body is uncertain.

Neuroendocrine tumours that have the ability to spread are called neuroendocrine carcinoma. They may be well-differentiated (resemble normal cells) or poorly differentiated (look very abnormal).

Neuroendocrine tumours and carcinomas occur at the following sites in the GI tract:

  • esophagus
  • stomach
  • small intestine
  • appendix
  • large intestine (colon and rectum)

There is no uniform system of staging GI neuroendocrine tumours based on the site of the tumour. Some doctors use TNM (tumour, nodes, metastasis) staging for the most common cancer at that site to assess GI neuroendocrine tumours. The stage or extent of GI neuroendocrine tumours or carcinomas is often described by doctors as:

  • localized — The cancer is still within the organ where it started.
  • regional spread — Cancer is found in neighbouring tissues or nearby lymph nodes.
  • distant spread — The cancer has spread to distant organs, such as the liver, bones or lungs.

The European Neuroendocrine Tumour Society panel has proposed new TNM staging for neuroendocrine tumours in each site of the GI tract. Their suggestions may form the basis for a consensus on staging of these tumours in future.

Find out more about grading, disease progression and prognosis and survival.

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Each person with gastrointestinal neuroendocrine tumours or carcinomas will have a treatment plan designed for them by their healthcare team. The team will recommend treatment options based on the specific characteristics of the cancer and the unique needs of the person.

It is important to have regular follow-up visits after treatment to watch for any recurrence or actively monitor and manage any remaining neuroendocrine tumours or carcinomas that cannot be completely removed.

Find out more about treatment options for neuroendocrine cancer and their side effects and follow-up after treatment.

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