Laser excision has been used with increasing success to treat
oral leukoplakia. The aim of the present study was to evaluate whether clinical healing of a
leukoplakia after
laser surgery is associated with a normal functional status of the new epithelium and whether pathological alterations in these parameters are related to the risk of local recurrence. The study population consisted of 13 consecutive patients with
oral leukoplakia in which clinical healing was achieved after
laser therapy using an
Nd:YAG laser (Model 6000,
Laser Sonics, Cooper
Laser Sonics). At the end of the
therapy, all patients underwent a second biopsy of the clinically healthy tissue. Epithelial cell turnover was evaluated before and after
laser surgery by Ki67
protein expression, and positive staining of more than 20% was considered abnormal. All patients were followed on a monthly basis. Eight patients had abnormally high Ki67 values before
laser therapy (mean 27.4 ± 6.2%), but the levels decreased significantly
after treatment (17.6 ± 8.5%; t = 2.6, p < 0.05). High Ki67 values persisted in three patients, and local recurrences in the new epithelium was observed in two of these patients. Kaplan-Meier statistics showed that the between-group difference was statistically significant (Chi square 7.3; p < 0.01). In conclusion, this is the first prospective study to show that clinical healing of
leukoplakia treated by
laser surgery may be accompanied by altered cell turnover in 20% of the cases. Ki67, as a marker of proliferative status, may be a prognostic
indicator in the mucosa replacing the lesion.