Biomarkers for Malignant Potential in Vocal Fold Leukoplakia: A State of the Art Review

MAGEA9 Expression in Vocal Fold Leukoplakia and Its Enhancement of Vocal Fold Leukoplakia Epithelial Cell Proliferation, Migration, and Invasion Through the NF-kB-MMP-2/9 Pathway

PURPOSE

The expression of MAGE-A9 in vocal fold leukoplakia (VFL) tissues and the mechanism underlying its role in the malignant transformation of VFL remain unclear. This study investigated the role of MAGE-A9 in the proliferation, migration, and invasion of VFL epithelial cells as well as the underlying regulatory mechanism.

METHODS

MAGE-A9 expression in VFL tissues was detected by immunohistochemistry. The CCK-8 assay, flow cytometry, and transwell assays were performed to determine the viability, cell cycle distribution and apoptosis, as well as migration and invasion, respectively, of primary cultured VFL epithelial cells. Ki67, cell cycle proteins, and proteins in the NF-kB-MMP-2/9 pathway were assessed by Western blotting.

RESULTS

MAGE-A9 expression was detected in 54.5% (18/33) of vocal fold polyps, 48.9% (44/90) of VFLs, and 84.8% (28/33) of laryngeal cancers. Significantly higher levels of expression were found in laryngeal cancer than in vocal fold polyps and VFL tissues (P < 0.001). The expression of MAGE-A9 tended to increase with the severity of VFL dysplasia. In VFL epithelial cells, the overexpression of MAGE-A9 significantly increased the viability, proliferation, migration, and invasion of the cells and reduced the level of apoptosis. The cell cycle effects of MAGE-A9 overexpression included an increased proportion of cells in the G2 and S phases and a decreased proportion of those in the G1 phase (P = 0.002), leading to an altered G1/S phase transition. MAGE-A9 overexpression also significantly increased p-IKBα, p-p65, MMP2, and MMP9 levels while decreasing those of IKBα. All of the effects of MAGE-A9 were inhibited by treating the cells with the IκBα phosphorylation inhibitor BAY 11-7082.

CONCLUSION

MAGE-A9 expression tended to increase with the severity of dysplasia in VFL and was significantly higher in laryngeal cancer than in VFL. MAGE-A9 was shown to promote the proliferation, migration, and invasion of VFL epithelial cells via the NF-kB pathway and downstream targets such as MMP-2/9.

CSPG4 overexpression implicates higher risks of recurrence and tumorigenesis after surgical intervention of vocal fold Leukoplakia

BACKGROUND

Vocal fold leukoplakia (VFL), a precancerous lesion of the larynx, is characterized by white plaques on the vocal fold mucous membrane. Currently, there are no reliable biomarkers to predict the recurrence and malignant transformation of VFL. Considering chondroitin sulfate proteoglycan 4 (CSPG4) as a biomarker for malignant tumors such as laryngeal squamous cell carcinoma (LSCC), we conducted this cohort study to evaluate the prognostic influence of CSPG4 expression on VFL patients.

METHODS

This study included 44 patients with surgical intervention of VFL. CSPG4 expression in VFL were observed using immunohistochemistry, and the relationship between the prognosis of VFL patients and CSPG4 expression were investigated using Spearman correlation analysis and multiple Cox regression models.

RESULTS

During a median follow-up of 89.3 months, recurrence occurred in 19 postsurgical VFL patients, and malignant transformation occurred in 10 patients. The recurrence and malignant transformation group showed significant differences in the H-SCORE of CSPG4 (P = 0.005 and P = 0.045) compared to the the non-recurrence group and the non-malignant transformation group. And the CSPG4 expression level was positive correlation with recurrence and malignant transformation (0.306 or 0.416, spearman correlation confident). Receiver operating characteristic curve analysis indicated that CSPG4 H-SCORE has predictive value for poor prognosis (areas under the curve, 0.742 and 0.710; cut-off points, 82.5 and 177.5, respectively). Multiple Cox regression analysis revealed a statistically significant effect of lesion size (P = 0.014) and CSPG4 H-SCORE (P = 0.005) on recurrence as well as pathological type (P = 0.001) and CSPG4 H-SCORE stratified by 177.5 (P = 0.039). Our survival data indicated that higher CSPG4 expression was associated with a shorter time of recurrence (P = 0.003) and tumorigenesis (P<0.001).

CONCLUSION

CSPG4 overexpression indicates higher risks and shorter time of postoperative VFL recurrence and tumorigenesis. Detection of CSPG4 expression in VFL may be a novel approach to assess the outcome of VFL patients.

Recurrence and malignant transformation of laryngeal leukoplakia treated with CO2 laser: A systematic review and meta-analysis

BACKGROUND

Laryngeal leukoplakia (LL) is a white lesion with high potential of recurrence and malignant transformation. Currently, CO2 laser has become the primary surgical treatment for LL, and the recurrence and malignant transformation rates after treatment vary widely.

OBJECTIVE

We performed a systematic review and meta-analysis dedicated to evaluating the rates of recurrence and malignant transformation of LL lesions treated with CO2 laser and exploring relevant risk factors for recurrence or malignant transformation.

METHODS

Literature searches were conducted on ProQuest, PubMed, Web of Science, Ovid Medline, Embase, and Cochrane databases. Some articles identified through hand searching were included.

RESULTS

A total of 14 articles and 1462 patients were included in this review. Pooled results showed that the overall recurrence rate was 15%, and the malignant transformation rate was 3%. Subgroup analysis showed that the dysplasia grade was not a significant risk factor for the recurrence and malignant transformation of LL (P > .05).

CONCLUSIONS

The results of this systematic review and meta-analysis suggest that the CO2 laser is a safe and effective surgical instrument for the excision of LL, which yields low rates of recurrence and malignant transformation. The risk factors relevant to recurrence or malignant transformation remain unclear and require further investigation.

Malignant Transformation of Dysplastic Vocal Fold Lesions: A Systematic Review and Meta-Analysis

Importance

The reported rates of malignant transformation of dysplastic laryngeal lesions are highly variable, as is time to malignant degeneration.

Objective

To evaluate the rate of and time to malignant transformation of dysplastic laryngeal lesions based on the World Health Organization (WHO) dysplasia classification system.

Data Sources

PubMed, MEDLINE, Embase, CINAHL, CENTRAL, and Cochrane Reviews were searched from the date of database inception to June 8, 2023.

Study Selection

English-language articles assessing the rate of malignant transformation using the 2005 WHO dysplasia classification system were included in this systematic review and meta-analysis.

Data Extraction and Synthesis

The study was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data extraction was performed by 2 independent investigators. Study quality was assessed using a validated quality tool. When possible, data were pooled using random-effects meta-analysis.

Main Outcome Measures

The primary outcome measure was the malignant transformation rate in each laryngeal dysplasia category. Secondary outcome measure was the time interval over which malignant transformation had occurred.

Results

A total of 5585 records were screened, 61 full texts were assessed, and 18 retrospective cohort studies with 3243 participants were included in the final review. The weighted pooled mean malignant transformation rates of mildly, moderately, and severely dysplastic lesions were 10.9%, 23.3%, and 30.5%, respectively. Malignant transformation rate of nondysplastic laryngeal lesions was 4.5%. Moderately and severely dysplastic lesions had significantly higher odds of malignant transformation compared with mildly dysplastic lesions (moderate: odds ratio [OR], 2.90 [95% CI, 2.06-4.09]; I2 = 0%; severe: OR, 3.42 [95% CI, 2.11-5.52]; I2 = 40%). Lesions without dysplasia had a significantly lower odds of malignant transformation compared with lesions with mild dysplasia (OR, 0.48; 95% CI, 0.28-0.81; I2 = 0%). The overall mean time to malignant transformation was 28.8 months (range, 22.0-35.6 months) for all dysplasia grades.

Conclusion and Relevance

This systematic review and meta-analysis found that the rate of malignant transformation increased with the grade of laryngeal dysplasia. Moderately dysplastic lesions were more likely to undergo malignant degeneration compared with mildly dysplastic lesions.

Clinical significance of type IV vascularization of laryngeal lesions according to the Ni classification

Background

Scattered, small, dot-like intraepithelial papillary capillary loops (IPCLs) represent type IV epithelial vascularization according to "Ni classification" and are considered to be nonmalignant. According to the European Laryngological Society classification, these loops are malignant vascular changes. This contradiction has high clinical importance; therefore, clarification of the clinical significance of type IV vascularization according to the Ni classification is needed.

Methods

The study was performed between June 2015 and December 2022. All recruited patients (n = 434) were symptomatic, with macroscopic laryngeal lesions (n = 674). Patients were investigated using the enhanced endoscopic methods of narrow band imaging (NBI) and the Storz Professional Image Enhancement System (IMAGE1 S). The microvascular patterns in the lesions were categorized according to Ni classification from 2011 and all lesions were examined histologically.

Results

A total of 674 lesions (434 patients) were investigated using flexible NBI endoscopy and IMAGE1 S endoscopy. Type IV vascularization was recognized in 293/674 (43.5%) lesions. Among these 293 lesions, 178 (60.7%) were benign (chronic laryngitis, hyperplasia, hyperkeratosis, polyps, cysts, granulomas, Reinkeho oedema and recurrent respiratory papillomatosis); 9 (3.1%) were squamous cell carcinoma; 61 (20.8%) were mildly dysplastic, 29 (9.9%) were moderately dysplastic, 14 (4.8%) were severe dysplastic and 2 (0.7%) were carcinoma in situ. The ability to recognize histologically benign lesions in group of nonmalignant vascular pattern according to Ni (vascularization type I-IV) and distinguish them from precancers and malignancies was with accuracy 75.5%, sensitivity 54.4%, specificity 94.4%, positive predictive value 89.6% and negative predictive value 69.9%.

Conclusion

Laryngeal lesions with type IV vascularization as defined by Ni present various histological findings, including precancerous and malignant lesions. Patients with type IV vascularization must be followed carefully and, in case of progression mucosal lesion microlaryngoscopy and excision are indicated.

Digit ratio (2D:4D), laryngeal cancer and vocal fold leukoplakia

BACKGROUND

To date, there are no studies that have analyzed the possible influence of exposure to prenatal sex hormones on the risk of laryngeal cancer (LC) and premalignant laryngeal lesion-vocal fold leukoplakia (VFL). Digit ratio (2D:4D) is suggested to be a proxy of prenatal sex hormone exposure.

OBJECTIVE

To examine 2D:4D in patients with LC and clarify if it could add to the verified risk factors in estimating the overall risk of LC.

METHODS

511 subjects participated in the study. The study group included 269 patients: with LC (N = 114, 64 men) and VFL (N = 155, 116 men). Controls included 242 healthy individuals (66.40 ± 4.50 years (106 men)).

RESULTS

Predictive models estimating the risk of VFL and LC in women, based solely on predictors like smoking and alcohol consumption had a lower area under the ROC curve (AUC) than the model with left 2D:4D. AUC for the model estimating the likelihood of VFL increased from 0.83 to 0.85, and for LC from 0.76 to 0.79.

CONCLUSIONS

Low left 2D:4D may be associated with an increased risk of developing leukoplakia and laryngeal cancer in women. In the case of laryngeal cancer, left 2D:4D may serve as additional variable (to other known risk factors, such as smoking and/or alcohol consumption), which can improve cancer risk prediction.

Videolaryngoendoscopic and Stroboscopic Evaluation in Predicting the Malignancy Risk of Vocal Fold Leukoplakia

Background: Vocal fold leukoplakia (VFL), despite our knowledge of its etiopathogenetic factors, and the development of laryngeal visualization, remains a diagnostic and therapeutic challenge. Objective: This research aimed to explore the efficacy of clinical and morphological feature identification in videolaryngoendoscopy (VLE) using a three-tier classification, and videolaryngostroboscopy (VLS) in predicting the risk of VFL malignant transformation. Material and Methods: We examined 98 patients with VFL by flexible endoscopy under VLE and VLS. Morphological characteristics of 123 lesions including the surface, margin, and texture were assessed; then, VFL was subdivided into three types: I—flat and smooth, II—elevated and smooth, and III—rough. Based on the histopathological findings, 76 (61.79%) lesions were classified as low- and 47 (38.21%) lesions as high-grade dysplasia. Results: The inter-rater agreement between two raters evaluating the VFL in VLE was almost perfect (Cohen’s kappa = 0.826; p < 0.00; 95%CI 0.748−0.904). In ROC curve analysis, the AUC difference between Rater I and Rater II was 0.024 (0.726 vs. 0.702). In multivariate analysis, high-risk VFL was positively related to unilateral plaque localization (p = 0.003), the type III VLE classification (p = 0.013), absence of a mucosal wave (p = 0.034), and a positive history of alcohol consumption (p = 0.047). In ROC analysis, VLE had an AUC of 0.726, with a high sensitivity of 95.7% and low specificity of 40.8%. The NPV was high, at 93.9%; however, the PPV was low, at 50%. The proposed logistic regression model including features significant in multivariate analysis showed lower sensitivity (80.9% vs. 95.7%) and lower NPV (86.2% vs. 93.9%); however, the specificity and PPV were improved (73.7% vs. 40.8% and 65.5% vs. 50.0%, respectively). Conclusions: The combination of clinical history with endoscopic (plaque morphology) and stroboscopic examination (mucosal wave assessment) can fairly estimate the degree of dysplasia in VFL and thus is recommended for use in clinical settings. The findings of this study can be used to guide the decision regarding immediate biopsy or watchful waiting.

Serum expression of Vascular Endothelial-Cadherin, CD44, Human High mobility group B1, Kallikrein 6 proteins in different stages of laryngeal intraepithelial lesions and early glottis cancer

Background

The study was designed to evaluate the potential validity and utility of selected molecular markers in serum samples from patients with specific stages of laryngeal intraepithelial lesions that could serve as diagnostic tools in differentiation of benign and dysplastic lesions from invasive pathologies.

Methods

Prospective study included 80 consecutive patients with vocal fold lesions treated at the single otorhinolaryngology centre. All participants had surgical resection of the lesion. Blood samples were collected from each patient before the surgery. Final diagnosis was confirmed on histopathological examination and included 39 (48.75%) non-dysplastic lesions, eight (10%) low-grade dysplasia, six (7.5%) high-grade dysplasia and 27 (33.75%) invasive cancers. The ELISA procedures were performed according to the manufacturer's instruction. Individual serum concentration of selected proteins was reported in ng/ml: Vascular Endothelial-Cadherin Complex (VE-cad), CD44, Human High mobility group protein B1(HMGB1), Kallikrein 6.

Results

The highest mean levels of HMGB1, KLK6 and VE-cad were detected in sera of patients with low-grade dysplasia (81.14, 24.33, 14.17 respectively). Soluble CD44 was the most elevated in patients with non-dysplastic lesions (2.49). The HMGB1, KLK6 and VE-cad serum levels were increasing from non-dysplastic to low-grade dysplasia and followed by the decrease for high-grade dysplasia and invasive cancer, however the differences were not significant (p-values 0.897, 0.354, 0.1 respectively). Patients' serum had the highest CD44 concentration in non-dysplastic and low-grade dysplasia with the following decrease through high-grade dysplasia and invasive cancer. GERD symptomatic patients had higher levels of KLK6 and CD44 than other patients (p-value 0.06 and 0.084 respectively). There were no significant differences of biomarkers levels related to patients' gender (p-value from 0.243 to 1) or smoking status (p-value from 0.22 to 0.706).

Conclusions

VE-cad, HMGB1, CD44 and KLK6 did not prove to be reliable biomarkers implicating malignant potential within vocal fold hypertrophic intraepithelial lesions.

Singer’s Nodules: Investigating the Etiopathogenetic Markers Progressing Their Pathogenesis and Clinical Manifestations

Simple Summary

Vocal nodules, together with vocal polyps, are the most common benign vocal cord structures that are thought to be caused by extensive vocal abuse (shouting, talking loudly for prolonged periods) and are routinely treated surgically. However, surgical excision of these nodules, does not exclude the possibility of recurrence of these nodules, especially if lifestyle changes are not adapted to prevent phonetic trauma. Furthermore, the etiopathogenetic pathways governing the formation and maintenance of these nodules are not known. Herein, we investigated the etiopathogenetic markers for proliferation, apoptosis, growth, ischemia (tissue hypoxia), inflammation and innervation to elucidate the causative pathways. We found a profound and significant intensification of apoptosis in tissue epithelium, which strongly correlated with proliferative, ischemic, and inflammatory changes, highlighting the underlying complex interactions between various mechanisms on a cellular and tissue level, which occur during the morpho-pathogenesis of vocal nodules.

Abstract

Vocal nodules (or Singer’s nodules) are benign vocal cord structures which are commonly encountered by clinicians. Though phonetic trauma/abuse is thought to be the main cause of the development of vocal nodules, the exact etiopathogenesis remains unknown. Hence, we compared the immunohistochemical markers for proliferation (Ki-67), apoptosis (TUNEL), growth (EGFR), ischemia (VEGF), inflammation (IL-1α and 10), and immunoreactive innervation (PGP 9.5), in vocal nodule tissue samples obtained from 10 females (17–56 years) and vocal cord tissue from seven controls. A statistically significant increase in Ki-67, TUNEL, EGFR, VEGF and IL-1α expression was noted (p < 0.05) between nodule tissue and control tissue in both epithelial and subepithelial layers. However, the difference was non-significant for both IL-10 and PGP 9.5 (p > 0.05). All markers demonstrated moderate to strong positive correlations, except for IL-10. These findings suggest increased cellular growth and proliferation in vocal nodules coupled with a persistent presence of inflammatory and ischemic environment. Furthermore, global prevalence of apoptotic cells and decreased anti-inflammatory cytokines highlight the presence of underlying complex mechanisms in the etiopathogenesis of vocal nodules, with age having a negligible impact on the marker levels. Our results could potentially further our knowledge in understanding the effects of different treatment modalities available at the cellular level.