Several epidemiologic studies have shown that
oral cancer develops among individuals with a prior diagnosis of an oral premalignant lesion. Canceration chance in these patients is 17%, with the greatest rate occurring in the second year of observation. Based on this data, since 1981, 92
leukoplakias have been treated by out-patient
laser surgery at the Istituto Nazionale Tumori of Milano. The therapeutic technique was
laser excision to obtain a specimen for histology. Two groups were distinguished according to the diagnostic procedure. Thirty-three lesions (December 1981 to December 1982) were operated on without preliminary histologic examination, on the basis of a simple clinical diagnosis. Since January 1983 all
leukoplakias have been biopsied in a systematic way and those negative for
cancer treated with
laser. Histology of the specimen showed 5
squamous cell carcinomas (15%) in the group of patients who did not undergo preoperative biopsy. Postoperative histology showed
malignancy in 6 of 59 (10.2%) cases in spite of negative preoperative biopsies. Speckled and erosive
leukoplakias had the highest canceration rate. Three of 11 patients with
cancer were treated by knife excision or interstitial needle implantation because of margins in tumoral tissue or because they were not evaluable for injury by heat. Results have been satisfactory, only 2 of 54 followed
leukoplakias and none of the
cancers recurred during a 2 year follow-up.