Okay, things can be worked around with back issues - trust me, I have a lot of lower back problems.
First of all, Kingbeef's thread here in the BB forum is awesome. It's called "Do this Routine, Not that dumb one" or something to that effect. Tons of good information there.
I would suggest hopping on a fairly standard template. You need to do something like so,
Day 1 - Chest
Day 2 - Legs (Use leg press, leg extensions, hammie curls, calf raises, etc.)
Day 3 - Back
Day 4 - Off
Day 5 - Shoulders
Day 6 - Arms
Day 7 - Off
Everyone is different, so the number of work sets you'll need will be variable. I know people who do like 20-30 sets on leg day (I'm dead fucking serious,) but if I tried to do 15 total work sets I'd probably be the walking dead.
I can tell you that you need a whole hell of a lot more attention distributed throughout your entire body.
Really, again, good on you for overcoming cancer and all, that's awesome. There was a poster around here (he has a thread in the T-Cell) named DOHCrazy who had Thyroid cancer is crazy jacked and strong, so it can be done. But you will need a much more intelligent and well-thought out program to get the results you're looking for.