L.M.
I recently had a breast abnormality. I was sure it was cancer and was terrified. After all the anxiety and tests were done, turns out it was a very common benign growth.
I totally understand where you are coming from. We all fear for our own health as well as the health of our loved ones.
Take comfort in the fact that your loved one has addressed this immediately and is doing all the right things, instead of hoping it didn't actually happen and hoping it won't happen again, and doing nothing. Your loved one is doing everything they can, and quickly, which is setting him/herself up for the best outcome that is possible.
Things are rarely as bad as we envision them to be. All my best.