SAN ANTONIO -

The final part of KSAT 12 News anchorwoman Leslie Mouton's battle against breast cancer comes in the form of a pill called Tamoxifen.

Mouton explains what the drug does and why she has to take it:

Dr. Lisa Fichtel has plotted my battle against breast cancer from the beginning. The next weapon in this war is a tiny pill called Tamoxifen.

Tamoxifen is an anti-estrogen pill that has been known to decrease the risk of recurrence by 50 percent and of death by 25 percent.

There's a lot of power in this tiny pill.
I'm lucky enough to have the type of cancer that responds to it -- cancer with estrogen receptor cells.

"(The cancer cells) need the estrogen in order to grow," Fichtel said. "If we can block the estrogen from feeding them, they probably will die."

While Tamoxifen blocks the estrogen in the breast, it turns "on" the estrogen in other parts of the body like the bones. That will help fight osteoporosis. But it also turns on estrogen in the uterus.

"There's a small but increased risk of endometrial cancer because it's acting like estrogen and making those cells divide," Fichtel said.

There are also possible side effects like hot flashes and a decreased libido.

The doctor said that because the drug blocks estrogen, it makes your body feel like you're in menopause.

But it's a chance worth taking, if it keeps the cancer from coming back.

I will have to take Tamoxifen for five years.