It's great that your dad managed his first chemo round very well. I really empathize with your situation. Regardless of age, it is a tough balance act to treat the disease, alleviate the pain, and maintain quality of life. I think that's what we're all trying to do. It makes sense to fight cancer as aggressively as your Dad can tolerate, and as long as he agrees to it. That's probably the only way to not have any regrets later. It sounds like this is what your family is doing.
My friend's mother was 84 years old at stage IV lung cancer diagnosis. She was given chemo dosage appropriate for her age and physical condition. In between chemo treatments, her mother managed to go on trips to New York City, Great Britain, and other nearby places in California. If they had to do it all over again, they would 100%.
Re: Avastin, my dad received FOLFOXIRI and FOLFOX, both without Avastin. My dad responded very well to chemo, and his liver — initially inoperable due to the tumors' location — became resectable.
Best wishes to you, your dad, and your family.
Daughter to Dad age 67 @dx, Dec. 2013 (now 73)
Stage IV cecum, 4 liver mets, CEA 21.8
MSS, KRAS mutant (G13D), MLH1 mutant (V384D), and TP53 mutant (G245S)
1/14 FOLFOXIRI, 2x
2/14 FOLFOX, 1x
3/14 Right hemicolectomy, 2/38 nodes
4/14 FOLFOX, 4x
8/14 Liver resection
9/14 Liver tumor growth: microwave ablation
10/14 FOLFIRI, 6x
2/16 8 to 10 lesions in lungs
3/16 Avastin + 5FU, 72x
4/19 Growth in lungs, lymph nodes. FOLFIRI + Avastin, 4x (CEA 12.4)
7/19 Started Stivarga + Opdivo
10/19 Start Hospice