I have both been through chemotherapy and traveled a lot, but didn't do both at the same time -- didn't actually travel while on chemo.
I agree with most of the information above, but having had incidents of lost luggage 3 (three) different times, even on non-stop flights, I would never recommend putting any important medication in checked luggage. Always carry it on! I have never had any problem with bringing a significant amount of medication in my carry-on, though mine has always been pills, no liquids. I usually bring enough for every day of my trip, plus at least an extra week. And, yes, pull the "cancer" card if necessary, and escalate to a supervisor if you are given any problems about medication. But carry it on in hand luggage!
Don't hesitate to use a wheelchair. Fatigue & weakness might be an issue by 1/2 way through chemotherapy. And be vigilant about germs, as others have posted.