When to start taking tamoxifen

Is the standard of care to wait until after radiation to start taking tamoxifen? Both my medical and radiation oncologists said that I should start taking tamoxifen while radiation is being given.  Everything that I'm reading states that most wait until after treatment to start tamoxifen. Why is that? Does taking tamoxifen make cells less sensitive to radiation?

[CCF-RN,MSN-rf]

Dear carol in pittsburgh: The decision of when to take hormone therapy in relation to radiation therapy is usually dependent on the preferences of the physicians.  In our institution, our medical oncologists and radiation oncologists prefer to start tamoxifen after radiation therapy.

[lizziecee]

I started on tamoxifen whilst undergoing radiotherapy. Was then switched 4 months later to Arimidex. I didn't even think to ask the Oncologist whether it was okay for me to take Tamox - I just figured they know what they are doing.
Hope the Doc here can help you.

[Elle53]

Hi Carol,

My med onc told me to start taking the tamoxifen when I began radiation.  I asked my rad onc about this and  he said studies are not yet clear regarding the best time to start it.  He said it makes little difference to him - not a big deal.  Some doctors like to wait until radiation is complete because it may be easier to decipher what is causing possible side effects.  For example:  If someone has a side effect and is doing rads and tamox, it may be  harder to decipher which is causing the side effect.

Hope this helps.  Good luck to you!

[Carol in Pittsburgh]

Thank you both for your comments. I feel a bit better now that others are undergoing the same treatment plan.

Good luck to both of you.

Carol