Feng

Introduction

Cancer screening is the procedure that aims to detect cancer before any signs or symptoms of cancer arise; it is potentially useful for medical diagnosis because early detection of cancer greatly increases the chances for successful treatment [1]. For the case of oral cancer, screening is particularly important as survival does correlate with stage, making early diagnosis and treatment optimal for this disease [2]. Unfortunately, the diagnosis constantly rely on physical examination followed by biopsy confirmation, which could result in delay in diagnosis [3]. As such, more and more research are being conducted to develop easy-to-use, cost effective oral cancer screening devices to encourage and improve this important procedure.

Background

Currently, there is a number of devices available on the market for oral cancer screening purpose. Some examples are Velscope®, ViziLite® and Identafi®. Extended studies on most of these devices are currently available in literature[4].

ViziLite is a disposable capsule like device that relies on chemiluminescence in 430-580 nm. Although researchers found its potential utility in identifying occult epithelial abnormalities, ViziLite suffers from high false positive and negative levels, and thus limiting its clinical application [4].

Examination using a Velscope® device. Source: https://apteryx.com/velscope/.

VELscope® is a hand held device that emits 400–460 nm wavelength light to excite auto-fluorescence from fluorophores in the mouth. Some researchers suggest that 405 nm wavelength light was able to discriminate neoplastic and non-neoplastic tissue with high sensitivity and specificity [5]. However, there has also been a number of criticisms on VELscope® for the limited capacity to extend its use in general dentistry. Researchers are still trying to improve its specificity to allow wider clinical use [4].

Identafi® is a probe like device designed for multi-spectral screening of oral disease. It emits three types of light: white, violet (405 nm) and green-amber (545 nm) light. The white light provides classical visual inspection and the violet light is for similar purpose as in VELscope®. The green-amber light, through reflection spectroscopy, is used to excites haemoglobin molecules in the blood, in order to visualise the vasculature [6]. Researchers found that the use of Itentafi provides more data that conventional oral exam. However, it requires high level of clinical training in oral pathology to interpret the results, and thus limiting its usage for special reference centers [7].

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References

[1] https://www.who.int/cancer/detection/en/

[2] Ries LAG, Kosary CL, Hankey BF, et al. SEER Cancer Statistics Review, 1973-1995. Bethesda, MD, NCI.2. American Cancer Society, Facts and Figures, 2000.

[3] https://oralcancerfoundation.org/discovery-diagnosis/cancer-screening-protocols/

[4] Mascitti, M., et al. "An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology" Front. Physiol. 9, 1510 (2018)

[5] Roblyer, D., et al. "Objective detection and delineation of oral neoplasia using autofluorescence imaging", Cancer Prev. Res. 2, 423–431 (2009)

[6] Messadi, D. V., et al. "The clinical effectiveness of reflectance optical spectroscopy for the in vivo diagnosis of oral lesions", Int. J. Oral Sci. 6, 162–167 (2014)