Doubt about leukoplakia. Getting cancer?

Hi, I was habitual gutkha chewer for 5 years. One month back I noticed a ulcer on gum of upper wisdom tooth and a skin deposition at the joint of jaw in the same ( behind the wisdom teeth of right side, in the same line of linea alba).I gave up chewing tobacco habit for two weeks. The ulcer got healed. The deposition of skin did not heal. Then again I started chewing pan masala and betel nut without any tobacco and lime with occasional smoking. Within one week I was feeling pain while opening mouth because some soar near the deposition.so I visited a surgical oncologist. He said premalignancy infections.i.e. leukoplakia and white discoloration. And he prescribed to stop chewing everything and 1. Supplima Sachet( L-Glutamine,Vitamin A, E, C and selenium), Vitamin A chewable tablets and clohex mouthwash. After 2-3 days the soar/ tenderness got healed. But I developed pain at the gum of wisdom tooth again(where the ulcer appeared and got healed).wat are the chances of getting cancer?