Frank - I kind of just knew that the ulcer on my tongue was cancer, even though at first several doctors kept telling me they thought it was not anything bad (which delayed my diagnosis as even though deep down, I knew, I really didn't want to acknowledge it) I am a nurse, though, and an ulcer on the side of my tongue that wouldn't go away was a pretty classic sign...so I finally said let's stop messing around, and just do the biopsy!!