Lichen planus is not one of the major risk factors for oral cancers. There have been reported cases of SCC arising in a bed of LP, but the jury has never been in on whether or not LP was a precursor event to the development of OC. It is relatively common condition, with thousands of people in the US having it. As the previous poster said, any transformation is rare, if anyone can actually prove that it is the beginning of cellular changes that lead to dysplasia and malignancy at all.

Remember that tissue fluorescence, the science behind the VELscope, is non specific to oral cancers. It finds all kinds of things that have lost their fluorescence, including pizza burns, cheek bites, lichen planus, highly vascularized normal tissues like those under your tongue, keritanized and harmless tissues like the lina alba on the cheek that Gary mentioned, and much more. There are many reasons that tissues can lose their fluorescence and cancers are only a small fraction of them. While a useful tool, it is not diagnostic, only approved by the FDA for discovery (not diagnosis) of suspect tissue, and is only an adjunct to a proper visual and tactile screening by someone that understands what they are looking at.