Diagnostic Modalities for Squamous Cell Carcinoma: An Extensive Review of Literature-Considering Toluidine Blue as a Useful Adjunct

Abstract

Introduction Oral Squamous Cell Carcinomas have been considered as the most prevalent malignancies in the head and neck region and are frequently undiagnosed until symptomatic with an advanced stage of disease. So there is an urgent need to device methods for the detection of oral premalignant lesions and oral cancer at an early stage in order to improve the survival rate for patients. A number of tests have been done for the detection of oral cancer which include oral brush biopsy, the Vizilite, oral autofluorescence including chemiluscence, photodynamic detection, toluidine blue staining, methylene blue staining, incisional biopsy and many more. Material The article reviews various diagnostic modalities available at present for detection of squamous cell carcinomas and oral epithelial dysplasias based on advanced PUBMED search of the English language literature from the year 1972 to present in order to help us select the most suitable among them fulfilling the desired criteria of being non-invasive, highly specific and sensitive, economically viable, having a scope to be used for mass screening, easy to process, having low inter examiner variability and possibly not requiring high expertise to conduct and interpret the results. Conclusion After reviewing various diagnostic modalities, we conclude that toluidine blue staining emerges as a clear winner among all these and it can act as a valuable adjunct to incisional biopsy in detection of oral cancer and may not substitute it except in certain circumstances when its results are carefully correlated with the patient history and clinical characteristics of the mucosal disorder, considering the fact that incisional biopsy has been reported to cause dissemination of cancer cells in the circulation there by increasing the possibility of metastasis. We must emphasize that toludine blue is a screening modality and not a diagnostic procedure like biopsy and hence cannot replace a confirmatory biopsy as a whole

Long noncoding RNA LINC01133 inhibits oral squamous cell carcinoma metastasis through a feedback regulation loop with GDF15

“…OSCC is aggressive and tends to metastasize to the lymph nodes, and metastasis to the regional lymph nodes is strongly associated with poor prognosis of patients with OSCC . The 5‐year survival rate for OSCC has hovered near 50% for nearly half a century, which is one of the lowest survival rates in malignant tumors . Certain studies revealed that selected protein molecules such as EGFR, RAS, P53, and VEGF were involved in OSCC carcinogenesis .…”

“…5,6 The 5-year survival rate for OSCC has hovered near 50% for nearly half a century, which is one of the lowest survival rates in malignant tumors. [7][8][9] Certain studies revealed that selected protein molecules such as EGFR, RAS, P53, and VEGF were involved in OSCC carcinogenesis. 10 However, the detailed mechanisms of OSCC metastasis have not yet been fully clarified.…”

A histochemical study to identify nodal micro-metastasis in oral squamous cell carcinoma

“…26,27 Toluidine blue, a vital acidophilic metachromatic die that stains acidic tissue components being simple, cost effective and easy to perform also has an application in staining tissue section. 28,29 Toluidine blue selectively stained the acidic tissue structures (sulfates, carboxylates, and phosphate radicals); this affinity mechanism of differentiation from rest of cells was still not clearly understood. [29][30][31] Toluidine blue is used mostly for staining of frozen sections of basal cell carcinomas (BCCs) during surgery due to its ability to accentuate the tumor's mucopolysaccharide-rich stroma.…”

An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology

“…In conclusion, despite the fact that ViziLite ® facilitates the identification of hyperkeratotic areas and may increase the visibility of mucosal lesions, the main limitation is currently the high proportion of false positive and false negative tests, regarding the identification of dysplastic areas rather than hyperkeratosis ( Chhabra et al, 2015 ).…”