Supporting the

Neuroendocrine Cancer Community

Carcinoid Syndrome

Apr 29, 2022

Carcinoid Syndrome is primarily associated with Neuroendocrine Tumours (NETs) that form in the Small Bowel, but may also occur in about 10% of primary Lung or Gynaecological (uterus, cervix, ovary and vagina) NETs. It may not present in the early stages of disease, being a more common occurrence once a Neuroendocrine Tumour has spread to the liver (metastasised). This may be because of the way blood circulates around the body and the role the liver plays in normalising hormone balance.

The blood flow to and through the mid or lower part of the body, flows through the liver on its way back to the heart and lungs. If a primary tumour occurs in this part of the body and is producing too much peptide or hormone, the levels within the circulating blood carry this excess to the liver. An important role of the liver is to maintain health balance by regulating circulating amounts of peptide or hormone. As the blood flows through the liver, it is filtered to remove any excesses or abnormalities – reducing the potential for symptoms and / or harmful effects.

However, if the primary has spread to the liver and is producing too much peptide or hormone there, it may bypass the liver’s ability to filter and remove it – making Carcinoid Syndrome more likely to be experienced.

One exception is the lung, if a primary there is producing too much peptide or hormone, not all of the blood is filtered by the liver and therefore there is a higher potential for developing Carcinoid Syndrome before spread of disease occurs.

The hormones and peptides most commonly associated with Carcinoid Syndrome include Serotonin, Histamine and Kinnins. These help in several important ways such as keeping the bowel working properly, the immune response – and, by acting as messengers, they can carry signals around the body to maintain normal body functions – such as heart rate, blood pressure and breathing. Abnormal levels can result in diarrhoea, abdominal (tummy) cramping, flushing, palpitations and / or wheezing. A combination of 2 or more of these symptoms, due to too much serotonin, histamine and / or kinins, is called Carcinoid Syndrome. Approximately 40% of those with Carcinoid Syndrome may also be at risk of complications such as Carcinoid Heart Disease.

For those with diarrhoea:

NCUK provide wallet alert cards for those who may require quick access to toilet facilities – they can be ordered free here.

Toilet finder apps are available for both Apple and Android devices from the App Store or Google Play. 

Radar Key: The National Key Scheme (NKS) offers independent access to locked public toilets around the country. Toilets fitted with National Key Scheme (NKS) locks can now be found in shopping centres, pubs, cafés, department stores, bus and train stations and many other locations in most parts of the country.

Further information about Neuroendocrine Cancer syndromes can be found here.

Further information about Neuroendocrine Cancer Complications can be found here.