The TIA will be much more of a concern for the FAA than the leukemia, but both may involve lots of additional red tape. If the leukemia is gone, that shouldn't be a problem. The TIA represents an elevated risk of CVA while in flight, so the FAA will need reassurance that it isn't likely to happen again. Because of your medical history, you'll need a special issuance of your medical from the FAA, but it's entirely doable if you are willing to trudge though all the red tape, provided that you're in good health today.
The FAA is mainly concerned with the risk of you being incapacitated in flight. Your objective is to convince them that this risk is extremely low. Best to talk it over with a doctor familiar with aviation medicine (but NOT an AME, save that for the actual exam), to make sure you know the proper protocol and procedures to follow to minimize the bureaucracy that you'll have to deal with.
Your medical issues might possibly interfere with a career as a commercial pilot, depending on exactly what you want to do, but you should still be able to get a private pilot's license and fly for fun in any case.