A good friend of mine had stage 4, aggressive and widespread Hodgkins Lymphoma. As you say very rare.
They gave her a 5% chance of survival. This was 5 years ago. She's been clear for the last two after loads of chemo and God knows what treatment.
Being fit and healthy obviously helped, as I took up boxing last September I have a fair idea of some of the training you do. To go back to that after cancer. Fair play to you mate. Take a strong will and a lot of self determination.