Recurrence rates after surgical removal of oral leukoplakia-A prospective longitudinal multi-centre study

Knowledge, Attitude, and Practice of Dutch Dentists on Oral Leukoplakia and Their Possible Role in Its Follow-Up

OBJECTIVE

To assess the knowledge, attitude, and practice of Dutch dentists on oral leukoplakia (OL) and to what extent these aspects are related to whether or not dentists regularly monitor patients with OL.

MATERIAL AND METHODS

A self-developed questionnaire was distributed via a web survey among a sample of dentists participating in an intervision program. Of 1626 invited dentists, 437 (26.9%) answered the questionnaire; 52.6% were females and 47.4% males, 36.4% were 44 years or younger, 24.0% were 45 to 54 years old and 39.6% were 55 years or older, 94.1% were general dental practitioners, 60.2% were practice owners, and 49.9% work more than 31 hours per week.

RESULTS

In total, 57.0% performed regular follow-up of patients with OL. Compared to dentists who do not perform regular follow-up of patients with OL, those who do were more confident in performing control, were more likely to be practice owners, checked a greater number of oral subsites during dental check-ups, had encountered more cases of suspected oral cancer among their own patients, and were more likely to implement effective policies when faced with mucosal lesions without a clear diagnosis. The vast majority of all participants indicated that their knowledge about oral mucosal diseases, OL, and oral cancer is limited. Just over half reported receiving insufficient education on these topics during their dental study.

CONCLUSIONS

It seems that interested dentists who have an affinity for oral mucosal diseases can properly fulfil the controlling and detecting role on selected patients with OL. Additional education on various aspects of OL is required.

CLINICAL RELEVANCE

In the Netherlands, interested dentists can responsibly follow up on a large proportion of patients with OL.

Effect of the combination of diode laser ablation with photodynamic therapy for oral leukoplakia with epithelial dysplasia: a retrospective study

OBJECTIVE

Photodynamic therapy (PDT) has become a promising treatment option for oral leukoplakia (OLK), but its clinical efficacy and efficiency remain limited. The aim of this study was to assess the effect of combining diode laser ablation with PDT for OLK with epithelial dysplasia.

METHODS

Forty-one patients diagnosed with OLK with epithelial dysplasia (mild, moderate, severe) were recruited in the study. All patients received one session of laser ablation, followed by 1-3 sessions of aminolevulinic acid (ALA) -PDT using a 635 nm laser at 100 mW/cm2 power density at a dosage of 100 J/cm2. The treatment effect was evaluated 1 month after therapy and every 3 months thereafter for a total of 12 months.

RESULTS

All patients responded to the combined therapy. The complete and partial response rates were 61.0% and 39.0%, respectively. Lesion size ≤200 mm2 was associated with complete response (P < .05). During the 12-month follow-up, recurrence occurred in 13 patients. The cumulative rate of malignant transformation was 7.3%.

CONCLUSIONS

Diode laser ablation combined with PDT is an effective and high-efficiency treatment modality for OLK with epithelial dysplasia, particularly for lesion size ≤200 mm2. However, recurrence and malignant transformation still exist after therapy.

Recurrence in Oral Leukoplakia: A Systematic Review and Meta-analysis

The management of oral leukoplakia (OL) is challenging because of a high risk for recurrence and malignant transformation (MT), and recurrent OL is associated with a higher risk of MT than nonrecurrent OL. The present meta-analysis aimed to examine the association between OL recurrence and surgical techniques used for their management as well as their clinicopathological factors. Electronic searches were conducted in EMBASE, PubMed, Scopus, and Web of Science to retrieve studies reporting OL recurrence after surgery. The pooled proportion of OL recurrence after surgical excision was estimated. Subgroup analyses were conducted based on the surgical technique, data type, grades of epithelial dysplasia, anatomical subsites, clinical type and size of the lesion, surgical margin, and risk habits. Meta-regression analyses were conducted to identify the association between age, sex, and follow-up duration and OL recurrence. The risk of MT based on the recurrence status was also estimated. A network meta-analysis was performed to determine the surgical modality associated with the least OL recurrence. Eighty studies with a total of 7,614 samples and various surgical modalities (laser-based techniques, conventional scalpel surgery, cryosurgery, and photodynamic therapy) were included in the meta-analysis. A pooled proportion of recurrence of 22% was observed. Laser-based surgeries resulted in fewer OL recurrences than other surgical modalities, and the combination of laser excision and vaporization was identified to be the best treatment approach. OL in the retromolar area and multiple sites, nonhomogeneous OL, advanced age, female sex, inadequate surgical margin, retrospective data, and betel quid chewing habit were significantly associated with higher OL recurrence. Recurrent OL showed a 7.39 times higher risk of MT than nonrecurrent OL. These results suggest that the combination of laser excision and vaporization might reduce OL recurrence. Furthermore, OL in older patients, females, and nonhomogeneous OL need close monitoring after any surgical therapy.

Evaluation of Clinical Outcomes and Recurrence After Surgical Excision of Oral Leukoplakia: A Prospective Cohort Study

OBJECTIVE

This study aimed to evaluate the clinical outcomes and recurrence patterns in cases of surgical excision of oral leukoplakia and identify key factors associated with disease recurrence and malignant transformation.

MATERIALS AND METHODS

Thirty patients aged 18-70 years who were diagnosed with oral leukoplakia through clinical and histopathological evaluation, with lesions larger than 1 cm2 requiring surgical excision, and who had ceased tobacco use or irritant habits for at least two months before surgery were considered. All the patients were monitored for 18 months postoperatively. Recurrence was defined as the reappearance of leukoplakia at or near the surgical site. Postoperative complications, including infection, scarring, and functional impairments affecting speech or mastication, were comprehensively documented at each follow-up: one week, one month, three months, six months, 12 months, and 18 months after surgery. The data were subjected to statistical analysis.

RESULTS

Overall, 27% of patients experienced recurrence, with higher recurrence rates in nonhomogenous lesions (40%), tobacco users (35%), and dysplastic lesions (100%). Factors such as a history of tobacco use and histopathological dysplasia were strongly associated with an increased risk of recurrence.

CONCLUSION

This study highlighted the significance of lesion type, dysplasia, and patient risk factors such as tobacco use in predicting postsurgical recurrence. Close follow-up and risk factor modification are recommended to optimize patient outcomes.

The value of regular follow-up of oral leukoplakia for early detection of malignant transformation

OBJECTIVES

Evaluate whether regular follow-up of oral leukoplakia (OL) resulted in early detection of malignant transformation (MT).

METHOD

Two hundred and twenty-two consecutive patients with OL (147 females, 75 males); median follow-up period of 64 months (range: 12-300). Three groups were distinguished: group A (n = 92) follow-up at the hospital; group B (n = 84) follow-up by their dentist; group C (n = 46) lost to follow-up.

RESULTS

OLs in group B compared to group A, were smaller in size (<2 cm; p < 0.001), showed more hyperkeratosis (p < 0.001) and less moderate/severe dysplasia (p < 0.001). MT occurred in 45 (20%) patients: 32 (35%) in group A, five (6%) in group B and eight (17%) in group C. There was no significant difference in clinical tumour size between group A (median: 15 mm, range: 1-40) and group B (median: 10 mm, range: 3-25; p = 0.496). Tumour size was smaller for patients in groups A and B (median: 10 mm, range 1-40) compared to group C (median: 33 mm, range: 3-100; p = 0.003). There was a positive correlation between tumour size and interval between the last visit in all patients (p = 0.022).

CONCLUSION

Regular follow-up of OL resulted in early detection of MT. If properly selected, follow-up of OL performed by the dentist seems feasible.

Expression of FAP in Oral Leukoplakia and Oral Squamous Cell Carcinoma

OBJECTIVE

This study aimed to investigate the potential of fibroblast activation protein (FAP) as a biomarker in the progression of oral leukoplakia (OLK) carcinogenesis. This was achieved by evaluating FAP expression at different levels of the organisation, namely oral normal mucosa (NM), OLK, and oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Altogether, 88 paraffin-embedded tissue samples were examined, including 55 cases of OLK, 13 cases of OSCC, and 20 cases of NM (control group). An exhaustive investigation was performed to examine FAP expression in NM, OLK, and OSCC tissues via immunohistochemistry (IHC). The relationship between FAP expression and clinical pathologic characteristics was analysed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB) also proved the expression of FAP in NM, OLK, and OSCC cells. Aberrant FAP expression in OLK and OSCC was explored using in vitro experiments.

RESULTS

Immunohistochemical results showed that high FAP expression was significantly correlated with histopathologic grade (P = .038) but not correlated with age, sex, or region (P = .953, .622, and .108, respectively). The expression level of FAP in NM tissues (0.15 ± 0.01) was minimal, whereas it was observed in OLK (0.28 ± 0.04) and OSCC (0.39 ± 0.02) tissues with a noticeable increase in expression levels (P < .001). The expression level of FAP in OLK with severe abnormal hyperplasia (S-OLK) tissues (0.33 ± 0.04) was significantly higher than in OLK with mild abnormal hyperplasia (MI-OLK, 0.26 ± 0.02) and OLK with moderate abnormal hyperplasia (MO-OLK, 0.28 ± 0.03) tissues (P < .001 and P = .039, respectively). The results of RT-PCR illustrated that the relative expression of FAP mRNA in OLK cells (2.63 ± 0.62) was higher than in NM cells (0.87 ± 0.14), but lower than in OSCC cells (5.63 ± 1.06; P = .027 and .012, respectively). FAP expression was minimal in NM cells (0.78 ± 0.06), modest in OLK cells (1.04 ± 0.06), and significantly elevated in OSCC cells (1.61 ± 0.09) based on the results of WB (P < .001).

CONCLUSIONS

Significant variations in FAP expression were observed in NM, OLK, and OSCC tissues and cells. These findings revealed that FAP may be a reliable biomarker for the early diagnosis and evaluation of OLK carcinogenesis.

New insights into the role of the oral leukoplakia microenvironment in malignant transformation

Oral leukoplakia is the most frequent and potentially malignant lesion of the oral cavity. Although dysplasia grading remains the main factor for risk assessment, challenges persist in determining the exact risk of transformation, and the literature has focused on studying alternative biomarkers. The interaction between dysplastic epithelial cells and the microenvironment starts early, and the communication is mainly mediated by lymphocytes, inflammatory factors, fibroblasts, and the extracellular matrix, leading to dysplastic progression. Leukoplakia-infiltrating leukocytes (LILs) and leukoplakia-associated fibroblasts (LAFs) play crucial roles in the dysplastic microenvironment. The immune response is related to intraepithelial T lymphocyte infiltration, mechanisms of immunosuppression coordinated by regulatory T cells, M2 macrophage polarization, and increased numbers of Langerhans cells; in contrast, fibroblastic and extracellular matrix factors are associated with increased numbers of pro-tumorigenic myofibroblasts, increased expression of metalloproteinases vs. decreased expression of TIMPs, and increased expression of chemokines and other inflammatory mediators. The microenvironment offers insights into the progression of leukoplakia to carcinoma, and understanding the complexity of the oral microenvironment in potentially malignant diseases aids in determining the risk of malignant transformation and proposing new therapeutic alternatives.

Early Detection of Oral Potentially Malignant Disorders: A Review on Prospective Screening Methods with Regard to Global Challenges

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists.

Progression to malignancy in oral potentially malignant disorders: a retrospective study of 5,036 patients in Ontario, Canada

OBJECTIVES

Determine the rate of malignant transformation (MT) of oral potentially malignant disorders (OPMDs) and risk factors for transformation.

STUDY DESIGN

The OPMD database (2001-2015) from 2 biopsy services in Ontario, Canada, was linked to the Ontario Cancer Registry to determine the rate of progression to oral squamous cell carcinoma (OSCC). Clinical and histologic features of progressed and non-progressed cases were compared to determine risk factors for progression.

RESULTS

The MT rate was 6.4% (322/5,036 cases). The mean time for cancer development was 51.2 months. 33.6% of cases (107/322) progressed after over 60 months. The risk of cancer increased with age and was higher in non-smokers. The MT rate was highest in the tongue (11.4%), followed by the floor of mouth (7.1%) and gingiva (6.5%). Histologic grade was associated with progression to cancer (P < .0001). Atypical verrucous-papillary lesions with no or mild dysplasia predominantly affected older patients' gingiva, and the progression rate was significantly higher than conventional mild dysplasia (9.2% vs 3.2%, P = .0002).

CONCLUSIONS

Our population-based retrospective study showed that <10% of OPMDs progressed to cancer, which could take many years. Atypical papillary-verrucous proliferation without high-grade dysplasia is a subtype of OPMD requiring further study.

Evaluating surgical excision to prevent progression of oral precancerous lesions: Highlighting randomized controlled trials and cohort studies

Currently, surgical excision remains a common intervention for oral precancerous lesions (OPL). However, the studies focusing on conventional surgery by scalpel for OPL are not analyzed collectively in detail. Therefore, the objective of this short communication is to summarize and evaluate the evidence on scalpel surgery in preventing the progression of OPL patients. There are 16 eligible studies on surgery management of the recurrence (13 studies) or malignant transformation (13 studies) of OPL. The pooled recurrence rate (95% confidence interval) of OPL patients received scalpel surgery and laser therapy is 29.5% (26.3-33.0%) and 32.2% (26.1-38.9%), respectively. The pooled rate of malignant transformation of OPL patients received scalpel surgery, laser therapy, and clinical observation is 8.9% (7.3-10.9%), 6.0% (3.5-10.1%), and 10.2% (8.6-12.1%), respectively. The important limitation of current evidence available for prognosis of dysplastic OPL is based on retrospective observational studies. It highlights that surgical management of OPL needs more randomized controlled trials and cohort studies to explore more reliable methods for routine clinical use to facilitate high- or low-risk stratification and further select more appropriate treatment option.

Clinical application of double V-Y advancement mucosal flap to repair tongue defect

OBJECTIVES

The repair of small- and medium-sized defects in the oral tongue has always been a challenge, and the effect of free flap and distal pedicle flap is still far from satisfactory. Tongue flap is an ideal choice for repairing small- and medium-sized defects. However, the disadvantages such as poor local morphology restricts the development of this operation.This study aims to investigate the efficacy of double V-Y advancement mucosal flap in repair of small- and medium-sized defects of the tongue defect.

METHODS

The clinical data of 15 patients with tongue defect lesions who were hospitalized in the Department of Stomatology, Third Xiangya Hospital of Central South University from March 2019 to May 2022 were retrospectively analyzed. After the lesions were completely excised, the mucosa and part of the tongue defect were left. One V-Y advancement mucosal flap was designed anteriorly and posteriorly to the defect. The superficial mucosa was incised gradually all around, preserving the deep median muscle tip. The 2 flaps were freed toward the middle of the defect, and the anterior and posterior flaps were sutured together at the middle of the defect, with the donor area directly pulled together and sutured.

RESULTS

The double V-Y advancement mucosal flap survived in 15 patients, and the wounds healed at stage I. The postoperative follow-up time was 12-22 months, and the patients had no recurrence, with symmetrical tongue shape, and no traction and deformation in the affected tongue organs. Meanwhile, the intraoral flap was thin and flat, and healed well with the surrounding mucosa, without obvious flap contracture or tongue bite.

CONCLUSIONS

Double V-Y advancement mucosal flap has the advantages of flexible design, simple preparation, reliable blood supply, and good protection of the donor site, which may be one of the effective methods for repairing small- and medium-sized defects in the anterior tongue mucosa.

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.

V-shaped Folded Nasolabial Flap in the Repair of the Anterior Buccal Mucosal Defect

OBJECTIVE

To investigate the efficacy of V-shaped folded nasolabial flap in the repair of small-sized and medium-sized defects of the anterior buccal mucosa.

METHODS

From March 2019 to December 2021, 9 cases of male patients with anterior buccal mucosal lesions were enrolled in this study. After the lesions were completely excised, the mucosa and part of the buccal mucosal defect were left. A transverse V-shaped folded nasolabial flap was created with the pedicle located at the corner of the mouth and the long axis along the nasolabial fold. The lower part was lifted from the end to the pedicle. Next, from the level of the superficial musculo-aponeurotic system, the upper and lower parts were lifted from the end to the pedicle, and the V-shaped flap was folded and turned over through the buccal tunnel to repair the mucosal defect. The extraoral donor site was directly pulled and sutured.

RESULTS

The nasolabial flap survived in 9 patients, and the wounds inside and outside the mouth healed at stage I. The postoperative follow-up time was 4 to 32 months, and the patients had no recurrence, with symmetrical buccal shape, and no traction and deformation in the affected buccal organs. In addition, the linear scar had no obvious hyperplasia and was hidden in the affected nasolabial folds, without symptoms of buccal nerve injury, and the shape of the corner of the mouth was normal. The width and opening degree of oral fissure were not significantly reduced compared with those before operation. Meanwhile, the intraoral flap was thin and flat, and healed well with the surrounding mucosa, without obvious flap contracture, buccal bite, or incomplete closure.

CONCLUSION

Overall, V-shaped folded nasolabial flap has the advantages of flexible design, simple preparation, reliable blood supply, and protection of the donor site, which may be one of the effective methods for repairing small-sized and medium-sized defects in the anterior buccal mucosa.

Oral cancer prediction by noninvasive genetic screening

Oral squamous cell carcinomas (OSCCs) develop in genetically altered epithelium in the mucosal lining, also coined as fields, which are mostly not visible but occasionally present as white oral leukoplakia (OL) lesions. We developed a noninvasive genetic assay using next-generation sequencing (NGS) on brushed cells to detect the presence of genetically altered fields, including those that are not macroscopically visible. The assay demonstrated high accuracy in OL patients when brush samples were compared with biopsies as gold standard. In a cohort of Fanconi anemia patients, detection of mutations in prospectively collected oral brushes predicted oral cancer also when visible abnormalities were absent. We further provide insight in the molecular landscape of OL with frequent changes of TP53, FAT1 and NOTCH1. NGS analysis of noninvasively collected samples offers a highly accurate method to detect genetically altered fields in the oral cavity, and predicts development of OSCC in high-risk individuals. Noninvasive genetic screening can be employed to screen high-risk populations for cancer and precancer, map the extension of OL lesions beyond what is visible, map the oral cavity for precancerous changes even when visible abnormalities are absent, test accuracy of promising imaging modalities, monitor interventions and determine genetic progression as well as the natural history of the disease in the human patient.

Clinical predictors of malignant transformation and recurrence in oral potentially malignant disorders: A systematic review and meta-analysis

OBJECTIVE

We performed a systematic review dedicated to pooling evidence for the associations of clinical features with malignant transformation (MT) and recurrence of 3 oral potentially malignant disorders (OPMDs) (actinic cheilitis [AC], oral leukoplakia [OL], and proliferative verrucous leukoplakia [PVL]).

STUDY DESIGN

We selected studies that included clinical features and risk factors (age, sex, site, size, appearance, alcohol intake, tobacco use, and sun exposure) of OL, PVL, and AC associated with recurrence and/or MT.

RESULTS

Based on the meta-analysis results, non-homogeneous OL appears to have a 4.53 times higher chance of recurrence after treatment. We also found 6.52 higher chances of MT of non-homogeneous OL. Another clinical feature related to higher MT chances is the location (floor of the mouth and tongue has 4.48 higher chances) and the size (OL with >200 mm2 in size has 4.10 higher chances of MT). Regarding habits, nonsmoking patients with OL have a 3.20 higher chance of MT. The only clinical feature related to higher chances of MT in patients with PVL was sex (females have a 2.50 higher chance of MT).

CONCLUSIONS

Our study showed that some clinical features may indicate greater chances of recurrence after treatment and MT of OPMD.

Unexpected Candidal Hyphae in Oral Mucosa Lesions-A Clinico-Pathological Study

Background: Oral mucosal biopsies might harbor candidal hyphae (CH) in the absence of any clinical signs or symptoms. Aim: To assess oral mucosa biopsies for the frequency of unexpected CH and characterize their clinico-pathological features. Materials and Methods: All biopsy reports (2004−2019) were searched using CH/candida/candidiasis as key words. Cases with clinical diagnosis of oral candidiasis (OC) were excluded. Demographic data, health status, smoking habits, clinical features and diagnoses were collected. Statistical analysis included the chi-square test; significance was set at p < 0.05. Results: Of all the biopsies, 100 (1.05%) reported microscopical evidence of CH without typical clinical signs/symptoms of OC. Fifteen cases were from healthy, non-smoking patients. CH was common on buccal mucosa (38%) and lateral tongue (23%). The tip of tongue (OR = 54.5, 95% CI 9.02−329.4, p < 0.001) and lateral tongue (OR = 3.83, 95% CI 2.4−6.09, p < 0.001) were more likely to harbor CH-positive lesions. CH-positive lesions were diagnosed as epithelial hyperplasia (55%) and exophytic reactive lesions (30%). No correlation was found between CH and the grade of epithelial dysplasia. Conclusions: Microscopic evidence of CH embedded into oral epithelium without typical signs/symptoms of OC is rare, especially in healthy, non-smokers. Since CH was occasionally found in oral sites prone to local trauma and in association with reactive lesions, in absence of host co-morbidities, the contribution of local mechanical forces to CH embedment cannot be ruled out.

Azoxystrobin induces apoptosis via PI3K/AKT and MAPK signal pathways in oral leukoplakia progression

Background: Oral leukoplakia (OLK) is one of the oral potentially malignant disorders (OPMDs) with an increased risk of developing oral squamous cell carcinoma (OSCC). There is no ideal therapeutic drug yet. Our previous study showed azoxystrobin (AZOX) inhibited the viability of OLK cells and the incidence of mouse tongue cancer. However, its specific mechanism has not been clarified. Here, we used network pharmacology with experimental validation to investigate the roles and mechanisms of AZOX in OLK.

Methods: The targets of AZOX and OLK were obtained from online databases. The overlapping genes were identified by the Jvenn database. STRING and Cytoscape software were used to construct the PPI network. GO and KEGG enrichment analyses were used to analyze the biological function. Molecular docking and CETSA were used to verify the direct binding between AZOX and its key targets. 4NQO induced mouse tongue carcinogenesis model was constructed to clarify the treatment response of AZOX in vivo. TUNEL staining was performed to detect the effect of AZOX on apoptosis in mouse OLK tissues. CCK8 assay, flow cytometry, and western blot were used to detect the effect of AZOX on cell proliferation and apoptosis in DOK cells. The expression of PI3K/AKT and MAPK markers were analyzed by immunohistochemistry in vivo or by western blot in vitro.

Results: Venn diagram showed 457 overlapping targets, which were involved in the PI3K/AKT, MAPK, and apoptosis pathways, and the top 5 hub modules were TP53, STAT3, AKT1, MAPK1, and PIK3R1. AZOX was bound with the highest force to AKT and PI3K by AutoDock Vina. PyMOL software visualized that AZOX could fit in the binding pocket of the AKT and PI3K. The carcinogenesis rate of the mouse OLK in the high-dose AZOX group was significantly reduced. AZOX induced apoptosis in the OLK tissues and DOK cells, and the expression of PI3K, AKT, p-ERK was decreased, and the expression of p-p38 and p-JNK was increased. CETSA indicated that AZOX might have a direct binding with AKT and PI3K.

Conclusion: AZOX may induce apoptosis via PI3K/AKT and MAPK pathways in OLK. This study reveals the potential therapeutic targets of AZOX in OLK.

Diode Laser in the Management of Leukoplakia - A Retrospective Study

Introduction

Leukoplakia is among the most common potentially malignant disorders encountered in clinical dental practice. The treatment of leukoplakia includes nonsurgical and surgical management. The surgical treatment includes excision, electrocauterisation, laser surgery or cryosurgery. This retrospective study aimed to analyse the efficacy of diode lasers in the management of leukoplakia.

Methods

The sample consists of 56 cases with 77 leukoplakia sites treated with diode laser between January 2018 and December 2020 with a minimum of six months follow-up. For each patient, personal data was collected along with site of lesions, leukoplakia phase, type of treatment performed (laser ablation or laser excision), side effects, recurrences and malignant transformation. Inferential statistical analysis was then conducted.

Results

After applying exclusion criteria, 56 cases with 77 leukoplakia sites were included in this study. Males aged >45 years were predominantly affected. Homogeneous leukoplakia (48.1%) was the most common phase. Recurrences were noted in 19.48% of the cases. Compared to laser excision, laser ablation had more recurrences. Gingival lesions showed a higher recurrence rate than other sites in the oral cavity. None of the cases showed malignant transformation.

Discussion

Laser offers many advantages over other conventional methods including lesser postoperative pain and swelling, bloodless dry operating field and increased patient comfort and requires minimal local anaesthesia. The study concluded that diode laser is an effective surgical treatment modality for treating leukoplakia. Furthermore, the laser excision technique was found to be superior to laser ablation due to lesser recurrence.

Oral leukoplakia: A review of clinical features and trends in management

Introduction: Oral potentially malignant disorders (OPMD) conisit of the group of diseases of great importance for dentists. Oral leukoplakia (OL) has long been the subject of debate by numerous researchers. A common etiologic factor is tobacco, which is associated with oral cancer. The aim of the study is to indicate the severity of the lesion, the most common clinical characreistics and localization. The prevalence of leukoplakia in the world is 2.6% with a rate of malignant conversion ranging from 0.1% to 17.5%. Literature data about the prevalence and annual rate of malignant transformation, approximately 2%, indicate that these changes should be taken seriously and regularymonitored Conclusion: Occurate diagnosis provides the key to preventing to malignant transformation. Various medical and surgical treatment modalities for this lesion have been described. This article highlights various trends in the diagnosis and treatment of oral leukoplakia.

Oral leukoplakia in adolescents: Report of a rare case and review of the literature

The aim of this report was to describe a rare case of leukoplakia in a young patient without any risk factors for squamous cell carcinoma. An 18-year-old male patient presented with an asymptomatic white lesion on the right lateral border of the tongue. Microscopic examination of the excisional biopsy specimen displayed hyperkeratosis and acanthosis without epithelial dysplasia, which were consistent with the clinical diagnosis of oral leukoplakia. The patient is undergoing systematic and regular evaluation, and after 28 months of follow-up, no recurrence has been observed. This report showed that, although uncommon, adolescents and/or young adults can also be affected by oral potentially malignant disorders. Therefore, dentists should be aware of this condition to establish the proper diagnosis and management.

Expression of p53, p63, podoplanin and Ki-67 in recurring versus non-recurring oral leukoplakia

Oral leukoplakia (OL), a potentially malignant disorder, recurs in 40% of cases after surgical removal. Recurrence is a risk factor for malignant transformation. We aimed to examine the prognostic significance of four biomarkers related to cell proliferation: p53, p63, podoplanin (PDPN) and Ki-67 in predicting recurrence. Formalin-fixed-paraffin-embedded specimens from excised OL (n = 73, 33 recurrent; 40 non-recurrent) were collected in a prospective study. Immunohistochemistry was used to visualise expression of p53, p63, PDPN and Ki-67. Image analysis software was used for quantification of p53-, p63- and Ki-67-expressing cells, while PDPN was analysed visually. The expression of all four proteins were higher in recurrent compared with non-recurrent OL, only expression of p53 was statistically significant. In uni- and multivariable Cox regression analyses of individual markers, expression of p63 was significantly associated with higher recurrence risk (p = 0.047). OL with a combined high expression of both p53 and p63 had a significantly higher risk to recur [Log Rank, p = 0.036; multivariate Cox, HR: 2.48 (1.13–5.44; p = 0.024)]. Combination of p53 and p63 expression may be used as a prognostic biomarker for recurrence of OL.

Ablative fractional laser-assisted photodynamic therapy vs. ablative fractional laser for oral leukoplakia treatment: A randomized, controlled pilot study

BACKGROUND

Ablative fractional laser-assisted photodynamic therapy (AFL-PDT) is explored as an effective method in some premalignant diseases, whereas the effect of AFL-PDT on oral leukoplakia (OL), the best-known precursor of oral squamous cell carcinoma, remains undetermined.

METHODS

Forty-eight patients, histologically diagnosed with OL, were randomized (1:1) to receive either AFL-PDT or ablative fractional laser (AFL) treatment. All patients were followed up at 1, 3, 6 and 12 months postoperatively. The primary endpoints of efficacy and clinical recurrence and the secondary endpoint of side effects were assessed.

RESULTS

Forty-four patients completed the study. The 100% effective cure rate in the AFL-PDT group was higher than that in AFL group (80.9%, P<0.05) with 19.1% difference (95%CI: 0.7-40.0%). Compared to AFL group, recurrence observed at 6 and 12 months post-treatment tended to occur in fewer patients in the AFL-PDT group (P<0.05). No severe adverse events or systemic side effects were observed in either group.

CONCLUSIONS

AFL-PDT may effectively reduce recurrence of OL with high clinical efficacy and good tolerability, suggesting it may be a promising treatment for OL.

Identification of specific clinical risk factors associated with the malignant transformation of oral epithelial dysplasia

BACKGROUND

Factors that increase the risk of malignant transformation of oral epithelial dysplasia (OED) are not completely elucidated.

METHODS

A retrospective chart review was performed assessing risk factors for transformation of OED, and cancer staging for transformed cases at Sunnybrook Health Sciences Centre.

RESULTS

Two-hundred four patients were diagnosed with OED, and 16.7% (34) underwent malignant transformation. Risk factors associated with transformation included: heavy tobacco smoking, excessive EtOH consumption, non-homogenous leukoplakia, size >200 mm² , moderate dysplasia or greater than moderate, progression of dysplasia grades, and immunosuppression. Transformed cases followed for a dysplastic lesion were associated with a stage-I cancer diagnosis, and cancer cases with no prior biopsy were associated with a stage-IV diagnosis.

CONCLUSIONS

In addition to commonly cited risk factors, immunosuppression was associated with malignant transformation, including the use of topical steroids. Analyzing risk factors can help clinicians define risk of progression in patients with OED.

Regular clinical follow-up of oral potentially malignant disorders results in improved survival for patients who develop oral cancer

OBJECTIVES

To evaluate whether clinical follow-up programs of oral potentially malignant disorders (OPMD) result in earlier detection and improved survival rates if malignant transformation occurs, as compared to OPMD patients without follow-up and other patients with oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Three OSCC groups were retrospectively studied for disease stage at diagnosis and survival rates (N = 739): Group A, patients with OSCC with regular follow-up of preceding OPMD (N = 94); Group B, patients with OSCC with preceding OPMD but no follow-up (N = 68); Group C, patients with OSCC without previously known OPMD diagnosis (N = 577).

RESULTS

The patients with OPMD with follow-up (Group A) was diagnosed at a significantly earlier stage and have significantly higher survival rates compared to Group B (p < 0.001 and p = 0.022, respectively) and Group C (p < 0.001 and p < 0.001, respectively). There was no significant difference between Group B and Group C in terms of survival rate (p = 0.143) or stage at diagnosis (p = 0.475). Patients with OPMD and follow-up (Group A) had a 5-year net survival rate of 90.0% (95%CI 80.3-100.8%), as compared to 68.3% percent (95% CI 54.5-85.7) for Group B and 56.1% (95% CI 51.4-61.3) for Group C.

CONCLUSION

The results of this study indicate that regular follow-up of patients with OPMD results in earlier detection of OSCC (if malignant transformation occurs) and improved survival.

A Retrospective Cohort Study of Oral Leukoplakia in Female Patients-Analysis of Risk Factors Related to Treatment Outcomes

Background: The aim of this study was to make a comparison of clinicopathological characteristics of oral leukoplakia between male and female patients following carbon dioxide laser excision for oral leukoplakia and analyze the factors associated with the treatment outcomes in female patients. Methods: Medical records of patients with oral leukoplakia receiving laser surgery from 2002 to 2020 were retrospectively reviewed and analyzed statistically. Results: A total of 485 patients were enrolled, including 412 male (84.95%) and 73 female (15.05%). Regarding the locations, the predilection site of oral leukoplakia in male patients was buccal mucosa (p = 0.0001) and that for women patients was tongue (p = 0.033). The differences of recurrence and malignant transformation between both sexes were not significant (p > 0.05). Among female patients, area of oral leukoplakia was the risk factor related to recurrence (p < 0.05). Clinical morphology and postoperative recurrence were the risk factors related to malignant transformation (p < 0.05). Conclusions: In comparison with male patients, there was no significant difference of the postoperative recurrence and malignant transformation of oral leukoplakia in female patients. Among the female patients, clinicians should pay more attention to large-sized and non-homogeneous leukoplakia, and postoperative recurrent lesions.

Patient-reported pain after surgical removal of leukoplakia - an observational 1-year follow-up study

OBJECTIVE

Oral leukoplakia (OL) presents as a white lesion of the oral mucosa and is not typically associated with the sensation of pain. OL should be surgically removed when possible because it is considered a potentially malignant oral disorder (PMOD). This study assessed the pain sensations experienced by patients in association with the occurrence and surgical treatment of OL.

METHODS

Inclusion criteria were: a clinical diagnosis of OL; biopsy excision; and observation for at least 12 months in the ORA-LEU-CAN study. At the first visit, all the patients were asked about the occurrence of symptoms within the lesion. Ninety-four subjects were assessed over a period of 1 year. All patients underwent complete removal of OL. The patient cohort was divided into three sub-groups: (i) no pain before excision and at the 1-year follow-up; (ii) pain before excision; and (iii) pain at the 1-year follow-up.

RESULTS

Overall, pain was reported by 21.3% of the patients at the study start whereas 13.8% of the patients reported pain 1 year after surgical treatment. Patient-reported pain from the lesion at study inclusion was significantly associated with lesions found on the lateral side of the tongue (p=.002). Pain reported by patients one year after surgery was significantly related to female gender (p=.038) and the presence of epithelial cell dysplasia (p=.022).

CONCLUSION

We conclude that surgical removal of OL results in a low risk of long-term post-surgical pain. However, OL located on the lateral side of the tongue and in OL with dysplasia are more likely to be associated with pain.

Oral tongue leukoplakia: analysis of clinicopathological characteristics, treatment outcomes, and factors related to recurrence and malignant transformation

OBJECTIVES

The tongue is identified as a high-risk site for oral leukoplakia and malignant transformation. The purpose of this study is to investigate the clinicopathological characteristics and treatment outcomes of tongue leukoplakia and assess the factors related to recurrence and malignant transformation.

MATERIALS AND METHODS

One hundred and forty-four patients who received carbon dioxide laser surgery for tongue leukoplakia from 2002 to 2019 were analyzed statistically.

RESULTS

The follow-up period was 54.90 ± 54.41 months. Thirty patients showed postoperative recurrence (20.83%), and 12 patients developed malignant transformation (8.33%). The annual transformation rate was 2.28%. Univariate analysis showed that a history of head and neck cancer, size of lesion area, clinical appearance, and pathology were significant factors for both recurrence and malignant transformation. In the multivariate logistic regression, a history of head and neck cancer and size of lesion area were independent prognostic factors for recurrence, and a history of head and neck cancer was the only independent factor for postoperative malignant change.

CONCLUSIONS

Clinicians should adopt more aggressive strategies for tongue leukoplakia patients with a history of head and neck cancer.

CLINICAL RELEVANCE

These results may help clinicians gain a better understanding of oral tongue leukoplakia.

Gingival Leukoplakia: Hyperkeratosis with Epithelial Atrophy Is A Frequent Histopathologic Finding

White lesions on the gingiva and palatal mucosa may represent reactive keratoses, including specific diseases such as benign alveolar ridge keratosis, or nonreactive keratoses, such as true leukoplakia, the latter being associated with a high recurrence rate at this site. The aim of this study is to determine the histopathologic features of gingival keratoses. Hyperkeratotic lesions from the gingiva, palatal mucosa, and alveolar ridge mucosa were available for evaluation after excluding specific keratotic lesions such as candidiasis. There were 321 biopsies from 296 patients and approximately half of the cases (159/321, 49.5%) were reactive keratoses. The rest of the 162 biopsies from 149 patients (76 females; 51.0%) represented true leukoaplakias. The most common location was the gingiva (73.2%) followed by the palatal mucosa (17.0%). Hyperkeratosis/parakeratosis not reactive (HkNR) represented 43.8% of cases; 45.7% were dysplasia or carcinoma, and the rest were not readily classifiable as reactive or non-reactive keratoses. Histopathologic features commonly noted in the HkNR lesions include sharp demarcation (72.7%), corrugated surface (53.5%), and epithelial atrophy (48.1%). A lymphocytic band was noted in 8.5% of the cases, mostly associated with epithelial atrophy (5/6 cases). Seven patients with 17 biopsies from noncontiguous sites likely had proliferative leukoplakia; the most common location was the gingiva (88.2%) and the most common diagnosis was HkNR (52.9%). HkNR is a common histopathologic diagnosis for leukoplakias on the gingiva, and these lesions frequently exhibit thick hyperkeratosis, epithelial atrophy and a lymphocytic band at the interface.

Recurrence in Oral Premalignancy: Clinicopathologic and Immunohistochemical Analysis

Oral leukoplakia (OL) has a propensity for recurrence and malignant transformation (MT). Herein, we evaluate sociodemographic, clinical, microscopic and immunohistochemical parameters as predictive factors for OL recurrence, also comparing primary lesions (PLs) with recurrences. Thirty-three patients with OL, completely removed either by excisional biopsy or by laser ablation following incisional biopsy, were studied. Selected molecules associated with the STAT3 oncogenic pathway, including pSTAT3, Bcl-xL, survivin, cyclin D1 and Ki-67, were further analyzed. A total of 135 OL lesions, including 97 PLs and 38 recurrences, were included. Out of 97 PLs, 31 recurred at least once and none of them underwent MT, during a mean follow-up time of 48.3 months. There was no statistically significant difference among the various parameters in recurrent vs. non-recurrent PLs, although recurrence was most frequent in non-homogeneous lesions (p = 0.087) and dysplastic lesions recurred at a higher percentage compared to hyperplastic lesions (34.5% vs. 15.4%). Lower levels of Bcl-xL and survivin were identified as significant risk factors for OL recurrence. Recurrences, although smaller and more frequently homogeneous and non-dysplastic compared to their corresponding PLs, exhibited increased immunohistochemical expression of oncogenic molecules, especially pSTAT3 and Bcl-xL. Our results suggest that parameters associated with recurrence may differ from those that affect the risk of progression to malignancy and support OL management protocols favoring excision and close monitoring of all lesions.

A Randomized Controlled Trial on Efficacy of Surgical Excision of Nondysplastic Leukoplakia to Prevent Oral Cancer

The aim of this study was to evaluate the effectiveness of surgical excision to prevent cancer in patients with nondysplastic oral leukoplakia (OL). This study was the first randomized controlled clinical trial comparing surgical treatment with standard care in this group of patients. Patients were divided into two groups. The first group underwent standard care, that is smoking counseling, follow-up visits every 6 months, and control biopsy when indicated. The second group underwent surgical excision, together with standard care. Oral cancer onset was the primary outcome; secondary outcomes included healing, recurrence after surgery, onset of new lesions, and worsening of the primary lesions. The differences in distribution of the patients' and lesions' characteristics were investigated through nonparametrical tests (Wilcoxon rank-sum and Fisher exact). Univariate and multivariate logistic regressions have been performed to estimate the odds ratio of the treatment on the recurrence or worsening of the lesions. A total of 260 patients took part in the study of which 132 were women (50.8%); during the follow-up period, two subjects developed oral cancer, one for each arm. Surgical treatment, when compared with standard care, was associated with a lower probability of the treated zone to remain healed during the follow up period (OR = 7.43; 95% confidence interval, 2.96-22.66). In conclusion, it is possible to assumed that regular clinical follow-up could be considered a reliable standard of care among patients with nondysplastic OLs.Prevention Relevance: Oral white patches can transform into cancer and none has provided clinical guidelines to prevent it. For the first time ever, we have showed that the clinical follow up of non dysplastic lesions was able to provide benefits if compared with surgical excision.

High-risk human papillomavirus in patients with oral leukoplakia and oral squamous cell carcinoma-A multi-centre study in Sweden, Brazil and Romania

OBJECTIVES

Although causal associations between oral leukoplakia (OL), oral squamous cell carcinoma (OSCC) and high-risk human papillomavirus (HR-HPV) have been speculated upon in several reports, conclusive evidence has not been presented. This study investigates whether the number of cases of HR-HPV in OL has increased over time and whether the prevalence of HR-HPV-positive OL differs in various parts of the world.

PATIENTS AND METHODS

A total of 432 patients with OL from Sweden, Brazil and Romania were analysed. Patients were divided into historical (1992-2002) and contemporary (2011-2017) cohorts from the respective countries. Seventeen patients with OL developed oral squamous cell carcinoma (OSCC). A real-time PCR assay, targeting HPV sub-types 6,11,16,18,31,33,35,39,45,52,56,58 and 59, was performed to detect HR-HPV in patients with OL.

RESULTS

In the Swedish and Romanian cohorts, none of the investigated HPV sub-types were detected. In the Brazilian cohorts, five patients with OL (3%) were positive for HR-HPV, including four patients from the contemporary cohort (HPV 16, 31, 33) and one from the historical cohort (HPV 11). All the cases of OL that transformed into OSCC were HR-HPV-negative, as were the corresponding tumours.

CONCLUSIONS

In summary, the prevalence of HR-HPV in OL is low in all the tested countries, and the incidence has not changed over time. HR-HPV in OL does not seem to be a driver of oncogenesis.

Laser excision of oral leukoplakia: Does it affect recurrence and malignant transformation? A systematic review and meta-analysis

Oral leukoplakia (OL) is a white lesion with high potential of recurrence and malignant transformation. The variable clinical and histopathological features of OL may potentially impact both treatment and prognosis. Current literature shows that post treatment rates of recurrence and malignant transformation vary widely. The use of surgical lasers have been proposed with the objective of improving outcomes. We performed a systematic review and a comprehensive meta-analysis dedicated to pooling the rates of recurrence and malignant transformation of OL lesions treated using the main types of surgical lasers available. Scopus, MEDLINE/PubMed, and Embase were searched electronically. A total of 36 articles met the inclusion criteria. Selected studies included OL lesions that were treated by evaporation or excision using Nd:YAG laser, Er:YAG laser, CO2 laser, KTP laser, or diode laser. The results of this systematic review and meta-analysis suggest that surgical laser excision of OL may decrease recurrence rates but have no effect on the malignant transformation of OL when compared with conventional treatments.