I had a kitty that had fibro sarcoma. It was on his gums rather than vaccine induced. He was diagnosed in early September last year and was put to sleep on October 5th. If you search the Cat Health section, you can read about his situation. His name was Morgan. I'm very, very sorry to hear about your situation. Give Tiger as much love and attention as you can. You won't regret it.

Here is the link to Morgan's cancer thread.