Cancer at 21
I can sympathise with you, I wish I could offer something positive.
18 years age I had testicular cancer and this spread to liver, lungs and stomach. I lost my class 1 medical as I expected, but after 5 years and still having yearly check ups and scans at the Royal Marsden Hospital (RMH) the CAA only granted me a class 3 with a safety pilot restriction.
I discussed this with RMH and they were somewhat surprised at the restricition imposed. My cancer, if it was to return would be caught early enough to treat and not in their eyes and years of experience a safety risk. A medical Proffessor at The RMH wrote to the CAA, but unfortunatly nothing was done.
It was felt the CAA was over cautious.
It took a further 5 years to get my class 1 certificate back.
I would like to think that with the more modern drugs and lower side affects that the CAA would have caught up with the times and see that Cancer can be treated and that it shouldnt affect your flying as long as your hospital is constantly monitoring you.