Cancer is a medical diagnosis, not an identity. It colors who you are just as any major experience would, be it pregnancy, pets, kids, diabetes, etc. However, it does not define you or your future.
For loved ones, give offers of help, but be specific. Patients don’t have the capacity to figure out what would be helpful most of the time. If you plan to do something in honor of the person, ask first if they are comfortable with that. I had a family member walk in my honor twice and make a big deal about it and want me there. I felt like a prize pig on display and it felt awful.