Hi sir., The process of OSMF turns into cancer depends on many things...at this stage doing a surgery and getting his mouth opening back to normal will largely improve his confidence. Also steroid therapy and cessation of habits will considerable reduce the chance of this turning to a cancer. Also consider natural therapies like yoga and  diet  change will help him to prevent this turns to a cancer

Hii..OSMF is precancerous condition...that means if your friend quit his habit completely from now, cancer can be prevented. But if he continues the habit, then there are chances for this lesion to convert it to the cancer. No need to worry now. He just have to quit the habit , try mouth opening exercises, & consult a dentist for injection therapy.

Cancer has different stages, in the initial stage it has symptoms that may later convert to non curable type.Since your friend has already gone through treatment and cured ,why fear again until you resume habits like Tobacco chewing.Please follow all the instructions given by the doctor don't stress yourself.

To know the current situation of the osmf,there are certain investigations to perform. Through this,we can diagnose current status. Based on that treatment can be planned. You can consult through this regarding information on investigations and prognosis of condition.