Hi Sam and welcome to OCF. First congrats on quitting. Second..I'm happy to hear you have a biopsy scheduled. It has been my experience that if something in your mouth doesn't heal within 2 weeks or so it's time to get it biopsied. As far as an allergy/cancer relation, I have not heard of anything like that.
I wish you much luck and please let us know what happens. Always feel free to ask any questions you can think of.
Suzanne