When to take Tomaxifen?

When is Tomaxifen usually started, before or after radiation?   I have just finished 8 chemotherapy sessions ( 3 weeks apart) and am going to start radiation (5 times a week for six and a half weeks)) Monday.   My radiation Oncologist says to start Tamoxifen and take it during radiation.  I thought my Chemo Oncologist said to start it after the radiation,but guess I misunderstood him, because he now says to start it during radiation.    What are the pro and cons of each?

I am to take the Tamoxifen for 5 years.  I am a little afraid of it, because I read that one should notify one's doctor if one has cararacts before taking it. It sometimes causes cataracts and other eye problems.  My eyes have always been rather sensitive.   I have a cataract in one eye that I will have to have surgery on after the radiation.   I fear that the pill will make it worst,  or even worse than that , will make a cataract in the other eye.  What are the chances of this?

[CCF-RN,MSN-rf]

Dear seven7:  There is no absolute right or wrong with regard to when to start the tamoxifen.  Most recommend starting it during radiation so that you are addressing any systemic disease while the radiation deals with the local problem.  Although there is a slightly higher risk of developing a cataract while on tamoxifen, it is only slightly higher (about 1%) than the normal risk.

[jivodd]

A related discussion, taking tomaxifen as preventive to high risk for cancer was started.