My new girlfriend says that she does not want me smoking cigars because they cause cancer. Any advice?

She is a great girl and she is the best one that I've had. The only thing is she said that she does not want me smoking cigars because they cause cancer and it had killed her great-grandfather and she does not want me ending up the same way. Me in my thirties, I haven't really thought about it. I really enjoy smoking cigars, but the girlfriend says she is not going to be able to put up with it. What should I do?