It was a difficult decision to make, after seeing one of my parents go downhill with Chemo. The experiences we hear of with human Chemo can give one pause for thought. Actually I was scared to death of it initially for Daisy. Now I regret not being more agressive, but that is second guessing, and second guessing is never good after an experience like this.
On another forum when a pet owner hesitates about Chemo, my answer usually is - try it. If the side effects are interfering with the quality of life then back out of it. More often than not the indicators come in quickly. If the cancer doesn't respond dramatically, then it's time to back out to just Prednisone, and that will give 1-2 months followed by a quick ending. If the cancer has already hit the liver (time for Milk Thistle?) and digestive system, then it may be very difficult to prevent nausea, at which time quality of life has to be considered. For most of the Lymphoma crowd, the results of Chemo are dramatic. For other cancers Chemo may not be a very good option or effective. The point of my posts was to demonstrate there is no blanket statement for Chemo in dogs as to whether it's evil or good. Also it was to show that although I lean heavily towards traditional medical therapy, that did not prevent me from looking for any edge that supplements might give my puppy in her fight. Each of the supplements I listed except maybe the Lycopene were researched via medical publications before I included them in the diet. As you suggest maybe one or more helped. Maybe none helped. But it was worth a try.