I do not believe that there is a clear answer to the question" Can chronic irritation cause cancer?"
It is hard to separate the cause and effect in my opinion. A sore spot may be sore because it is precancerous. Opinions and believes by doctors about such a connection is mostly anecdotal and not based on strong data. It is still a good idea to have any chronic sore place checked by a specialist.

I Brook MD http://dribrook.blogspot.com/