Excision of oral leukoplakias by CO2 laser on an out-patient basis: a useful procedure for prevention and early detection of oral carcinomas.

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.