Hello XXXXXX,
As radical mastectomy may include removal of axillary lymph nodes, it is best to avoid antiperspirant, deodorants, as well as stong soaps shortly after the surgery especially if radiation therapy is also received.
After complete healing and recovery, then there is no problem using it unless there is any skin breakdown or any inflammation.
There has been reports correlating antiperspirant to breast cancer however, it seems to prove that it has no correlation: http://www.enotalone.com/article/7123.html
Take care!
Nurse
A Registered Nurse for 19 years.
You're always welcome.