I stopped using regular Deoderant after my Dx. Now post BMX I use a wonderful organic poweder that is made here in my town by Poofy Organics. (my friend actually works there!) They make organic Deo's too but once I moved to the powder, i find it lasts longer. I have been using the same powder since last summer. Still half full. Its expensive but to get a year out of it for $14 is not really that bad. If you have a WholeFoods by you they carry this brand too. https://poofyorganics.com/MemberToolsDotNet/Sho...

I had the same issue. It seemed worse on the side that the lymph nodes were taken out on. What I found that helped was rubbing some baking soda under my arms. I'm almost a year out and the problem has definitely gotten better. Hang in there!

Use rubbing alcohol on a cotton ball.

I was told no aluminum deodorants by my oncologist. I switched to Tom's, however it's not doing the job. I do notice it's worse on the side where my cancer was and lymph nodes removed. My step daughter is sending me some deodorant with essential oils that she makes. I looked on the cancer site about the oils and found that lavender and tree oil is not recommended for estrogen positive breast cancer patients. So I asked her to omit those. I'm anxious to see how it works.
I also bought for my travel bag a stone that's suppose be natural that seems to work well. I recently noticed it has aluminum in it :(.

I heard many years ago that we should not wear deodorant because it "causes cancer." Been meaning to ask my doctor about it but haven't. Have stopped wearing it though until I get an answer.