Hope you are just passing through also. Yes, unfortunately you can two unrelated cancers at the same time, although one started before the other.

I unknowingly had a type of sarcoma called GIST, very rare, for a number of years. The GIST did not metastasize, and the cells barely showed division, but it created hemorrhage in my stomach. I think it placed me in a state of lowered immunity, and that increased the likelihood of cancer elsewhere. That is my theory. Some people who know me the best agree with me.

For yourself, if you have no visible irritation or ulcers, it might be hard to get anyone to biopsy. It would not hurt to schedule an appointment with an ENT or Oral Surgeon who sees oral cancer to examine you and visit with them. If you have a flare-up again, try to get in to this same person so that they can see what is going on. Hopefully they would suggest something like this to you.

Best,
Anne