because of what you are seeing. They are going to keep popping up. They also tend to be quite aggressive, and have a high propensity for distant metastasis. It is uncommon to find and remove a feline mammary CA before it has already spread.

That said, I have a patient who I diagnosed a year ago (that's four years in "cat" years), who has been going in for weekly chemo all this time, and is still alive. The owner opted out of mastectomy, so of course new lumps are cropping up. But the oncologist says not to fuss over them - the chemo will (in theory) keep them from spreading. Quality of life is ok - she has kidney problems due to age and exacerbated by the chemo but it's not major.

This is one of those diseases that is virtually 100% preventable. I cannot recall a single case in a cat who was spayed on schedule. They all tend to be cats who at the age of ten still haven't been fixed. Except for the one male (neutered, FIV positive, former stray) - he was a WEIRD case. But human males can get it, too.