I am sorry Josie is ill, but I bet she will be just fine!! If she had to catch cancer, that sounds like the best kind to have. We have a rescue lab, they are just wonderful.
One of our kitties was just diagnosed with intestinal lymphoma. The vet tried to remove the tumor, but it's inoperable. So they sent him home for palliative care until he gets too sick. It really sucks, we lost one to IBD almost a month ago.