Malignant transformation of oral leukoplakia: a multicentric retrospective study in Brazilian population

Management of oral leukoplakia with an 808-nm high-power diode laser: a single-center experience

PURPOSE

High-power diode laser emerges as a promising approach to the treatment of oral leukoplakia (OL); however, its short- and long-term effects have been barely explored. This study evaluated the postoperative endpoints and the recurrence rate of high-power diode laser treatment in a well-defined series of patients with OL.

METHODS

A prospective analysis was performed on 22 individuals comprising 31 OL. The lesions were irradiated using the following protocol: Indium-Gallium-Arsenide diode laser, 808 nm, continuous-wave mode, 1.5-2.0 W, 780.0 ± 225.1 J, and 477.1 ± 131.8 s. Postoperative pain was assessed with a visual analog scale at three endpoints. Clinical follow-up was performed on all patients and the Kaplan-Meier test was used to analyze the probability of recurrence.

RESULTS

The series consisted mostly of women (72.7%) with a mean age of 62.8 years. A single laser session was performed in 77.4% of cases. The median score on the scale that assessed pain on the 1st, 14th and 42nd postoperative day was 4, 1, and 0, respectively. The mean follow-up period per lesion was 28.6 months (range: 2-53 months). A complete response was observed in 93.5% of OL cases, while 6.5% had recurrence. The probability of recurrence at 39 months was 6.7%. No patient experienced malignant transformation.

CONCLUSION

High-power diode laser for the treatment of OL is safe and effective during the trans- and postoperative period. These findings represent an alternative approach to the management of OL, mainly because a low recurrence rate was observed.

Clinical and Histological Prognostic Factors of Recurrence and Malignant Transformation in a Large Series of Oral Potentially Malignant Disorders

Background

Oral potentially malignant disorders (OPMDs) represent a heterogeneous set of different histological lesions, characterized by the capacity to transform in oral squamous cell carcinoma (OSCC). Despite optimal surgical treatment, approximately 20%–30% of OPMDs may evolve into OSCC. No clear clinical/histological factors are able to identify OPMDs at higher risk of malignant transformation.

Materials and Methods

We considered surgically treated patients with a diagnosis of OPMDs, enrolled from 1996 to 2019 at ASST Spedali Civili of Brescia without a diagnosis of OSCC within the previous 2 years. Clinical and histological characteristics were recorded. Outcomes of interest were recurrence-free survival (RFS), defined as the time from surgery for primary OPMD to any relapse of OPMD or malignant transformation, whichever occurred first, and carcinoma-free survival (CFS), defined as the time from surgery for OPMD to malignant transformation.

Results

We retrospectively reviewed 106 OPMDs cases. Median age at first diagnosis was 64 years old (IQR = 18.75); female patients comprise 51.9% of the cases. During a median follow-up of 30.5 months (IQR = 44), in 23.5% of patients, malignant transformation occurred. RFS at 1, 5, and 10 years was 92.4%, 60.9%, and 43.2%, respectively. Female sex and history of previous OSCC were independent risk factors for RFS. CFS at 1, 5, and 10 years of follow-up was 97.1%, 75.9%, and 64.4%, respectively. Previous OSCC was an independent risk factor for CFS.

Conclusions

In this large series of OPMDs, only previous diagnosis of OSCC was a prognostic factor for further OSCC occurrence. Given the lack of additional clinical/pathological prognostic factors, we advocate further studies into molecular characterization of OPMDs to better stratify the risk of malignant transformation.

Correlation of Soluble CD44 Expression in Saliva and CD44 Protein in Oral Leukoplakia Tissues

The aim of this study was to determine whether and how pan-CD44 protein expression in leukoplakia tissues correlates with positive SolCD44 test presence and their role in oral leukoplakia. SolCD44 and total protein expression in saliva were determined using an OncAlert^® Oral Cancer Rapid test. Comparison of paired associations of total protein, SolCD44, mean number of CD44 expressed epithelial layers in leukoplakia tissue, and macrophages below the basement membrane between control group and patients with leukoplakia showed statistically significant results (p < 0.0001). It is shown that the total protein indicates low or elevated risk of possible malignant transformation processes in leukoplakia. Statistically significant differences between higher total protein level and clinical forms of oral leukoplakia (p < 0.0001), as well as CD44-labeled epithelial cell layer decrease (p < 0.0001), were found. This possibly points to the onset of the stemness loss in leukoplakia tissue. CD9 antigen expression in the exosomes of the oral epithelium explained the intercellular flow of SolCD44 and other fluids in the leukoplakia area. We conclude that the OncAlert^® Oral Cancer Rapid test is a valuable screening method in daily clinical practice, in terms of complementing clinical diagnostics methods and to assess the potential for early malignancy.