The use of estrogen and progestin dropped off when a study conducted by Women's Health Initiative, WHI, showed that women who were taking them had greater risk of developing breast cancer. But there still is a debate on what actually causes the risk.

There was a 19 per cent risk found in women who used a estrogen therapy for 15 years when it came to breast cancer as compared to women who never used any.

The risk became 83 per cent among those women who used the therapy by combining estrogen and progestin together for 15 years and more.

It was pointed that these findings mean a lot of concern because the risk is increased by 83 per cent which is a huge risk.

Experts stated, "If taken for more than 15 years. Remember, if it was 100 percent risk, that would be equivalent to doubling your risk. This 83 percent is actually very similar to what came out in 2002."

Weight also plays an important role but it was stated that time was important when it came to taking the therapy.