Leukoplakias fall into different groups, those that are the kind you can watch and wait for awhile, as they have a low transformation rate into cancers (around 20%), and those that are more likely to develop into dysplasias, then cancers. Unfortunately while they do not always turn malignant, verrucous leukoplakias are in the later group, they are definitely considered precancers. Read that sentence again. They do not always turn malignant, but need to be dealt with since they are considered PRE cancers. Verrucous leukoplakias make up about 25% of all oral leukoplakias. The other risky type is called erosive leukoplakia and it has a much higher rate of transformation to malignancy, so that at least is the good news out of the two types that can truly be considered precancerous