Diabetes and Cancer

Diabetes carries an increased risk of cancer
Diabetes carries an increased risk of cancer

Studies have shown that diabetes carries an increased risk for a number of different forms of cancer.

Having cancer with diabetes can make achieving good diabetes control much more difficult but this can be relieved to some extent.

How is type 2 diabetes linked with cancer?

One theory for why a link may exist is that high levels of circulating insulin (known as hyperinsulinemia) can promote the growth of tumours.

In type 2 diabetes, insulin resistance commonly causes the body to produce more insulin than normal.

Another reason why a link may be present is where a harmful lifestyle may lead to obesity and therefore higher risks of both type 2 diabetes and cancer.

Cancer and type 2 diabetes

The risks of contracting the following cancers are shown to be doubled by the presence of type 2 diabetes:

A smaller increased risk, of 20% to 50% is seen for the following forms of cancer.

The one positive is that incidences of prostate cancer are actually lower for people with type 2 diabetes.

Cancer and type 1 diabetes

Links between type 1 diabetes and cancer are not so well recorded but it appears there is also an increase in risk of cancers for people with type 1 diabetes.

The cancers with the highest increase in risk tended to be different to those noted in type 2 diabetes.

The cancers with increased risk in type 1 diabetes include:

  • Stomach cancer
  • Cervical cancer

What are the symptoms of cancer?

The symptoms of cancer vary widely depending on which part of the body the cancer strikes.

What treatment options are open for cancer?

The main treatment options for cancer are surgery to remove the cancers or radiotherapy (also known as radiation therapy or radiation oncology).

Cancer treatment and diabetes control

Chemotherapy and use of glucocorticoids and steroids can exacerbate difficulties in achieving good diabetes control, particularly after meals.

For this reason, doses of chemotherapy may need to be reduced and glucocorticoids and steroids doses administered through the day rather than in larger, less frequent doses.

Nausea and vomiting can cause additional control difficulties in people with diabetes, particularly if strong anti-hyperglycemic medication is taken, such as insulin.

Speak to your healthcare team if diabetes control is becoming difficult to manage whilst undergoing cancer therapy.

Preventing cancer

The advice to help prevent cancer is to lead a healthy lifestyle which includes:

Cancer and metformin

Metformin is the most common type of medication taken for type 2 diabetes. The drug has been commonly linked with lower rates of a wide variety of cancers, particularly amongst people with type 2 diabetes.

A large number of different studies have produced evidence that metformin appears to lower the risk of developing cancer as well as increasing the survival rates of people with cancer.

Explore Cancer