Even though you had a bilateral mastectomy, there is still some breast tissue left. Mastectomy does not remove all the breast tissue.
Also, ifyour tumor was estrogen positive some breast cancer cells may have gotten into the bloodstream and you do not want them to grow. They need estrogen to grow so the Anastrozoledecreases the amount of estrogen that the body makes and the Tamoxifen stope the estrogen receptors on breast cancer cells from getting into the cells so they can't grow into another breast cancer tumor in another part of the body.
Hope this answers your question,.
Judy

Thank you Judy...I think i didn't explain it well. I'm not good in explaining. I understand your answer and it make sense but what I'm confused about is both breast are DCIS (ductal carcinoma in situ) not the invasive kind. They did total mastectomy and i was told by the surgeon who did the surgery they took out all the breast tissue. I'm reading a lot of the websites about Anastrazole and Timoxifen and both of these medicine are preventive for breast tissue only. So, if i don't have any breast tissue anymore and a DCS kind of cancer and not invasive what will these medicine do for me. One more is the reason I'm scared to take them because of the side effects especially uterine cancer.

Thank you again Judy...

The surgeon told you he took out all the breast tissue and was absolutely correct when referring to all the tissue that makes up the external breast.
However there is breast tissue that is attached to the chest wall (deeper down) and they try to get most of that breast tissue as well, but there is no guarantee that all of that remaining breast tissue attached to the chest wall was removed. And if there were a few cancer or precancer cells in that tissue it would not be detected by the original mammo or MRI's and you would not know until years later when those cells might grow and become cancerous.
So the meds are prescribed to take care of that possibility - even if it is very remote. Kind of an insurance policy that goes where the surgeon's knife cannot go.
You have taken Anastrazole for 3 months and now it is your choice whether or not you want to take Tamoxifen. Women on Tamoxifen usually have uterine ultrasound done every 6 mos or once a year to check for uterine cancer.
The choice is yours as to whether or not to continue with the Tamoxifen. Many women opt not to take Tamoxifen and are very comfortable with their decision. So that decision is yours to make. For the doctors there is only one choice, but for you there are two choices and there is no right or wrong choice - only the choice that gives you peace of mind.
Soyou should decide what is the best choice for you in this case.
Good luck and let us know what you decide.
Judy

Hi Judy,

I spoke to my oncologist and ask her if the Anastrazole are for breast tissue only and she said it helps to prevent the cancer cell from growing to the whole part of the body. So i decided to continue taking the medicine. But they did all this test cervix, papsmear and ultrasould and they found cyst but the result said they are not causing any problems and the cyst is fluid only. Do you have any idea if that is true because last January I had this painful cramps that lasted for 5 days and it's on and off. Then it happens again last Friday and it lasted 2 days and it is on and off too. I email both my oncologist and the obgyn dr if they can check this problem or is it really a problem or not.

Thank you for taking time to help me because I'm still emotionally and mentally disturb on what was going on with me.

There are fluid filled cysts that are not cancerous and can be drained. Some of them culd be large and press on other abdominal organs which mght be causng the pain you are experiencing at some times.
The size of the cysts may fluctuate with your menstrual cycle, and get bigger and smaller depending on the hormones present in your body.
When you start Tamoxifen your body will still be making estrogen which means that you still may be having these problems.
I would definitely have the doctors check you out and see if they can drain the cyst or give you some meds to shrink it to stop the cramping.
Let us know what the doctors say and how you are doing.
Judy