Mia,
I'm 41 too, so you have already started rad's, did you have to do chemo, what was your dx, i'm her2neu +, er, pr+, but my doc just called no spreading to the lymph nodes, all the cancer in the boob is gone, will have to have chemo, and herceptin, but not sure what else.
Good luck on the smoking I too have smoked for about 23 years, and the funny thing is I'm an avid sports person, I always work out, run, walk, aerobics. I can't imagine how much more of a sports person I would be if I did not smoke.
Has the smoking bothered you during rads? Yes you need to quit if you go on Tamoxifn, that can cause blood clots, so lets do this together and get this monkey off our back.
Randi