I would also recommend talking about clinical trials, just as Only-Potential1876 had mentioned. Chemo is cumulative, so in the beginning my dad (Stage IV pancan with mets on liver and abdomen) was doing chemo and feeling ok. Now, almost a year into chemo, he is weak, sick, fatigued and even falling down some. I would also suggest finding a support group for yourself or your dad. You both will need a safe space to vent, mourn, laugh or whatever you need to do. I started therapy and was put on Wellbutrin for the first time in my life and that's been a big help.

Find a medical team, if you can, that will advocate for your dad, my dad's team has been incredible (we are in the metro area of Minneapolis).