A trial looking at a way of preventing cancer of the womb lining (endometrial cancer) (POET)

This trial was trying to find out if a contraceptive coil that releases hormones could reduce the risk of pre cancerous cell changes in the lining of the womb (the endometrium). It is called the Mirena coil and your doctor may call it an intrauterine system (IUS). This trial was supported by Cancer Research UK.

This trial was only open to women who are at high risk of endometrial cancer because they are from a family that has Lynch syndrome. This is also known as 'hereditary non polyposis colorectal cancer' or HNPCC and is a rare gene fault that runs in families. If you carry the gene fault, you are at a greater risk of several different cancers. The risk of bowel cancer is increased most. But there is also an increased risk of other cancers, including endometrial cancer.

There are tests that can show areas of thickening of the womb lining and see if there are changes in the cells. The thickening of the womb lining is called endometrial hyperplasia. If there are changes in the cells, it is called atypical endometrial hyperplasia. Atypical just means abnormal. Hyperplasia means overgrowth of cells. Atypical endometrial hyperplasia can go on to become endometrial cancer.

The Mirena coil sits inside the womb and releases a small amount of the hormone progesterone. Because the progesterone stops the lining of the womb thickening, it may help to prevent atypical endometrial hyperplasia.

The aims of the trial were

• To find out if the Mirena IUS could reduce the number of women with Lynch syndrome who get atypical endometrial hyperplasia or endometrial cancer
• To learn more about the changes that take place in the cells of the womb lining
• To find out how well this type of surveillance worked and how this group of women felt about it