Usefulness of a fluorescence visualization system for the detection of oral precancerous and early cancerous lesions

Abstract

Abstract. Early detection of precancerous and early cancerous lesions could greatly reduce both the mortality and morbidity of oral cancer. The objective of this study was to analyze a fluorescence visualization (FV) system for the detection of precancerous and early cancerous lesions in rat tongue carcinogenesis and human oral cancerous lesions using for the first time a 4NQO rat model and human tissue. Based on the results from the rat tongue carcinogenesis model, under direct FV, the normal oral mucosa emitted various shades of pale green autofluorescence. In the precancerous and early cancerous cases, the lesion appeared as an irregular dark area. Histological examination of the lesions showed that the VELscope system had a sensitivity of 95% and specificity of 100% in discriminating normal mucosa from dysplasia/ carcinoma in situ (CIS) or invasive carcinoma. The proliferating cell nuclear antigen (PCNA) protein level was gradually increased with progression of carcinogenic transformation. Furthermore, the results of PCNA and FV loss (FVL) were correlated. Next, results from 17 patients were also presented. Histological examination of the lesions showed that the VELscope system had a sensitivity of 95% and specificity of 100% in discriminating normal mucosa from severe dysplasia/ CIS or invasive carcinoma. There were no normal epithelium cells in any of the FVL regions. Furthermore, to clarify the usefulness of FV compared to vital staining with iodine, we investigated the surgical margins of early oral squamous cell carcinoma (OSCC) tissues and compared the FVL and iodine unstained area (IU). The percentage of various types of dysplasia were almost equal when comparing the FVL and IU. These results suggest that this direct FV device has the potential for simple, cost-effective screening, detection and margin determination of oral precancerous and early cancerous lesions. IntroductionSquamous cell carcinoma (SCC) is the most frequent type of cancer in the oral and maxillofacial region, and its metastatic and invasive abilities result in a poor prognosis (1,2). Standard care for oral cancer includes a combination of surgery, radiation and chemotherapy. Although cancer treatment is progressing substantially, the survival rate of patients with oral cancer has not changed over the past 30 years (3). Early detection of premalignant oral mucosal abnormalities and SCC is preferred because early diagnosis and appropriate treatment decrease patient morbidity and improve survival (4). The clinical symptoms of precancerous lesions and early oral squamous cell carcinoma (OSCC) are varied and may be misdiagnosed as other conditions, including mucosal inflammation, hyperkeratosis, or traumatic ulceration.Autofluorescence is one potential technique that may be used to facilitate the visualization and detection of oral precancerous and early cancerous lesions. As early as 1924, it was discovered that the autofluorescence of tissues could potentially be used for cancer detection. Autofluorescence works on the principle that ...

Surgical margins in oral cavity squamous cell carcinoma: Current practices and future directions

“…A similar study ascribed a sensitivity and specificity of fluorescent visualization in discriminating between normal and dysplastic or malignant margin tissue to be 91% and 100%, respectively. They concluded that the VELscope device (LED Medical Diagnostics) had potential as a simple, cost‐effective screening tool to guide biopsies and margins in oral precancerous and early cancerous lesions …”

The luminance ratio of autofluorescence in a xenograft mouse model is stable through tumor growth stages

“…In this research, we transplanted the HSC‐3 OSCC cell line into nude mice and observed tumor growth over time, examining the levels of FAD and NADH, which are thought to affect the FVL change in the autofluorescence image. A feature of the luminance ratio is that it decreases when the FVL darkens in comparison with the luminance of normal tissue (Ohnishi et al, ; Westra & Sidransky, ; Yamamoto et al, ). Although there have been a few observations of change in the luminance ratio associated with tumor growth, our results indicated no significant temporal differences in the luminance ratios of tumor parenchyma and surrounding tissue over time (Figure b).…”

Molecular classification of autofluorescence excision margins in oral potentially malignant disorders

“…We have previously investigated the molecular mechanisms underlying LAF and DF in OPMD using RNA sequencing to elucidate correlations between autofluorescence behaviour and differential transcriptional mechanisms across histological groups (Kordbacheh, Bhatia, & Farah, ). It is recognised that the feature of autofluorescence that makes it advantageous in the detection of OPMD can also make it useful for the determination of excision margins (Elvers et al., ; Ohnishi et al., ; Poh et al., ). However, there are few studies that provide molecular validation for this application.…”