I probably wouldn't change much. I might quit my job. I'd spend as much time as possible with family-meaning, I'd throw away everything that kept me from spending every single moment I had left with them (except the pets). However, I would not poison myself with chemo/radiation treatments if I had a terminal cancer. The end would be bad enough without adding insult to injury.
We had a lady at my work that was told she had less than a year due to stomach cancer. She quit her job, traveled and enjoyed what time she had left. Spent money freely and was nearly broke by the time her time was supposed to be up. But.... she didn't die. She is beating the odds and doctors are stumped. Problem is she now hasn't had a job for over a year and no money. She is living with her elderly mother now and just waiting to die because she can't afford to do anything else and nobody will hire her when they find out she has "terminal" cancer.