I know this question was meant for Luella, but I wanted to help any way I could. I have a dog with cancer, and in my research, I came across a couple of things you might be interested in. One is a website called Natural-Wonder-Pets that sells an inexpensive herbal cancer treatment. If you read about how each herb works, it makes sense that it kills cancer. Also, if you use Dmso and Vitamin C directly on the tumor, it is supposed to help shrink it.
Hope that helps, I know what it's like to not be able to afford vet expenses for a sick animal.