Well, which is it? Does he have it, or is he in remission?
Having stood by my wife for 2 bouts of breast cancer, it can't be both.
The two are not mutually exclusive. Once you have an infectious autoimmune disease like cancer, MS, Lupus, Wegeners, rheumatoid arthritis and 100 others, you are susceptible for life!!
Being in remission simply means that the disease has been controlled by surgery, radiation, drugs, diet, prayer (likely a combination), and is no longer active.
I have a friend with Non-Hodgkins Lymphoma who took the same drug as Thompson and has been doing extremely well for the past 6 years.