CANCER RESEARCH UK CYMRU

How do hormones affect our risk of cancer?

Because they have such important roles, the levels of hormones in our bodies is carefully controlled. If these are too high, they can make our cells grow and divide uncontrollably and stop them from dying when damaged. This can lead to cancer.

Oestrogen. Women with the highest levels of oestrogen and related hormones have over twice the average risk of breast cancer and womb cancer. They may also have higher risks of ovarian cancer.

Testosterone. At the moment, it isn’t clear if high levels of testosterone in men increases the risk of prostate cancer. But we do know that prostate cancer cells depend on testosterone in order to grow.

Insulin. Insulin is most famous for controlling our bodies’ sugar levels, but it has many other functions. High levels of insulin have been linked to cancers of the bowel, womb, pancreas and kidneys.

Insulin also affects the levels of another group of similar hormones called insulin-like growth factors or IGFs. High levels of IGF-1 could increase the risk of prostate, breast and bowel cancers. Many scientists are studying the links between insulin, IGFs and cancer but at the moment, they are still unclear.