Estudio clínico de la leucoplasia oral y el tratamiento con láser de dióxido de carbono

Abstract

Oral leukoplakia is classified as an oral potentially malignant disorder with a high capacity for recurrence in which different methods have traditionally been used for its treatment. Objectives: to study and expose the clinicopathological characteristics of oral leukoplakia, and how they influence the evolution and treatment by means of vaporization of the lesions with CO? laser, assessing recurrence and malignant transformation at 18 months. The gene expression of the lesions was also analyzed to classify the genetic markers that can determine this possible malignant transformation. Methodology: prospective randomized study in patients who had been diagnosed with oral leukoplakia according to criteria proposed by the WHO. The study was carried out at the Dental Clinic of the University of Murcia. The study has followed the recommendations of the Helsinki declaration and was approved by the Ethics Committee of the University of Murcia (ID: 2225/2018) and the Biosafety Committee on Experimentation of the University of Murcia (ID: CBE 181/2018). Patients under 18 years of age, patients undergoing treatment for another oral pathology, pregnant or breastfeeding women, as well as decompensated systemic diseases were excluded. The treatment was performed by means of CO? laser vaporization of a total of 48 oral leukoplakias, with a maximum of three laser sessions each (a total of 102 vaporizations). The sample comprised patients of an average age of 61.3 years, of whom 25 were women and 23 were men. Follow-up was carried out for 18 months, assessing complications and post-treatment symptoms. Treatment efficacy was analyzed via ImageJ software. Results: Treatment success was observed with absence of lesions in 44% of the oral leukoplakias, mild recurrence in 23%, complete recurrence in 31% and a malignant transformation rate of 2%. Variables related to the lesion (clinical form, location, size and dysplasia) and variables related to patient habits (smoker, oral hygiene, body mass index and bruxism) did not show a statistically significant effect over the period of recurrence. A microarray screening was performed to find alterations in gene expression between healthy patients and patients with oral leukoplakia. The sampling procedure was conducted by means of saliva and oral mucosal exfoliation, resulting in 944 and 649 genes that were expressed differently from the healthy control, respectively. The identification of possible genetic markers that can determine the risk of an oral leukoplakia to transform into a carcinoma was attempted. Conclusions: surgical interventions with CO? laser are relatively simple and quick to perform, providing treatment success rates that stand out as a strength with regard to the mild associated morbidity involved. Even so, the follow-up of treated oral leukoplakias is essential and the classification of recurrences could be of great help for future action protocols against this pathology. The progression of oral leukoplakia to oral carcinoma seems to have a multifactorial genetic factor. Genes that vary their expression in oral leukoplakia have been identified and these genes are also altered in oral carcinoma, thus, a continuous alteration in the expression of these genes could play a key role in malignant transformation.