Risk factors for pituitary gland tumours

A risk factor is something that increases the risk of developing tumours. It could be a behaviour, substance or condition. Tumours can be the result of many risk factors. But many pituitary gland tumours develop in people who don’t have any of the risk factors described below.

Pituitary gland cancer (pituitary carcinoma) is very rare. Almost all pituitary gland tumours are pituitary adenomas, which are non-cancerous (benign). Pituitary adenomas mainly develop in adults, and the chance of developing these tumours seems to increase with age. They affect men and women equally.

Talk to your doctor about your risk. If you are at a higher than average risk for developing a pituitary gland tumour because of a genetic condition, you may need a personal plan for testing.

The following are risk factors for pituitary gland tumours. All of the known risk factors are not modifiable. This means that you can’t avoid them. Until we learn more about these risk factors, there are no specific ways you can reduce your risk.

Risk factors are generally listed in order from most to least important. But in most cases, it is impossible to rank them with absolute certainty.

There is convincing evidence that the following genetic conditions increase your risk. But only a small number of people with these conditions actually develop pituitary gland tumours. Find out more about genes and cancer.

Multiple endocrine neoplasia (MEN) is a group of rare hereditary conditions that cause tumours in the endocrine glands. The tumours are usually non-cancerous, but they are cancerous (malignant) in rare cases.

There are different types of MEN, which are each caused by changes (mutations) in different genes. Each type of MEN affects certain endocrine glands. MEN1 may cause tumours in the pituitary gland. The tumours are usually pituitary adenomas in the front part of the pituitary gland. MEN4 may also cause pituitary gland tumours.

Carney complex is a very rare genetic condition that increases the risk of developing several different types of tumours, including pituitary gland tumours. People with Carney complex usually have light brown spots on the skin.

Most people with Carney complex have a change in the PRKAR1A gene that is inherited from a family member. But some people do not have a change in this gene. Researchers are still looking for other abnormal genes that cause Carney complex.

Familial isolated pituitary adenomas (FIPA) is a hereditary condition in which pituitary adenomas develop in members of the same family. Only the pituitary gland is affected by this condition. FIPA is usually diagnosed when there are no symptoms or features of MEN1 or Carney complex.

Some members of a family can have FIPA caused by changes in the AIP gene. These changes often cause large pituitary adenomas that make too much growth hormone (growth hormone–producing adenoma). Too much growth hormone can cause increased growth of the skull, bones of the face, jaw, hands and feet (called acromegaly). Other types of pituitary adenomas can also develop in members of a family with FIPA, including adenomas that make prolactin and adenomas that don’t make extra hormones (non-functioning).

McCune-Albright syndrome is a very rare genetic condition that affects the bones, skin and endocrine system. People with this condition may develop pituitary adenomas.

McCune-Albright syndrome is caused by a change in the GNAS gene. This change is not passed from parents to their children. It happens by chance, usually early in life.

It isn’t known whether or not oral contraceptives are linked with pituitary gland tumours. It may be that researchers can’t show a definite link or that studies have had different results. More research is needed to see if using oral contraceptives is a risk factor for pituitary gland tumours.

To make the decisions that are right for you, ask your healthcare team questions about risks.