If I'd had cancer, I could have a reoccurence. Therefore, the ethical thing to do would be to inform potential serious partners about my prior cancer. Same thing with alcoholism. Relapse is entirely possible. Some things are deal breakers in potential relationships...having kids, not wanting to have kids, having financial problems, having mental health problems, having a criminal record, whatever. Anyone is entitled to refuse to date anyone they don't want to based on their personal deal breakers. No one is entitled to have a relationship just because they think they deserve one, despite their pasts. That's life.