There's no practical way to intentionally get cancer. Besides, there's other ways of dealing with this situation. Talk to you parents about your feelings and the things you want for your future. At 17, you can stand up to your parents and let them know what you feel. Refuse to participate in things that you don;t want to do. Maybe you can go live with your sister.

Your parents cannot make you go to college. If you want to have a different life, then go live it. You only need to put up with this stuff until you are 18. When you are 18 you can move out on your own, get a job, meet people, make friends, and do whatever you want.