Meta-analysis of two computer-assisted screening methods for diagnosing oral precancer and cancer

DNA-ICM as an adjuvant method applied on oral cytological specimens

OBJECTIVE

This study aimed to evaluate cytology diagnosis accuracy using adjuvant methods in clinical routine for oral cancer.

STUDY DESIGN

This prospective study was conducted on 98 patients with clinically potentially malignant or malignant oral cavity lesions. One oral lesion smear was taken from each patient using a cytobrush before biopsy and stored at PreservCyt Thinprep. Samples were cytologically analyzed, and DNA ploidy measurement was performed on the same slide. The diagnostic methods' accuracy was then calculated.

RESULTS

In clinical inspection, 61 patients had suspicious lesions for malignancy, whereas 37 had potentially malignant disorders. Cytology associated with DNA image cytometry presented a sensitivity of 81.2% and specificity of 90.9%. When analyzing lesions located in high-risk sites to oral malignancies individually, cytology associated with DNA image cytometry presented a sensitivity of 88.2%, specificity of 100.0%, accuracy of 90.0%, and Kappa value of 0.77 (CI 95%: 0.48-1.00).

CONCLUSIONS

Association between cytology and DNA image cytometry is an objective and non-invasive diagnostic method that demonstrated high sensitivity and specificity in diagnosing malignant epithelial squamous cell transformation in the oral cavity.

Current evidence on DNA aneuploidy cytology in noninvasive detection of oral cancer

DNA-aneuploidy cytology as a promising noninvasive tool in diagnosing oral precancer and cancer has been proposed in 2015. In this letter, we identified 9 studies on DNA aneuploidy cytology with special emphasis on using fresh tissue sample in detection of oral precancer and cancer. Evidence was updated as follows, for detection of OSCC in general oral lesions, the pooled sensitivity and specificity was 84.8 and 99.0 respectively; for discrimination of dysplasia and OSCC form oral lesions, the sensitivity and specificity was 75.7 and 76.8 respectively. On the whole, current evidence on the theme is not robust, and multicenter prospective studies are needed to consolidate the evidence.

Inter-and intra-observer agreement on the judgment of toluidine blue staining for screening of oral potentially malignant disorders and oral cancer

OBJECTIVE

Toluidine blue staining (TBS) is used for screening of oral potentially malignant disorders (OPMDs) and oral cancer. Nevertheless, the judgment of TBS is based on the observer's personal experience and largely considered subjective. The aim of this study was to evaluate the inter- and intra-observer agreement on the judgment of TBS for screening of OPMDs and oral cancer.

MATERIALS AND METHODS

Two hundred randomly ordered TBS images of OPMDs and oral cancer were judged twice independently by four clinicians and four graduated students majored in oral medicine, with an interval of 3 months. Inter- and intra-observer agreement was evaluated by the Cohen's kappa (κ) coefficient. The correlation between κ-value and individual experience was assessed by Spearman's correlation coefficient.

RESULTS

For the two sets of observation, good overall inter-observer agreement was found in the study (κ = 0.620 and 0.667). Sub-group analysis yielded good inter-observer agreement both for clinicians (κ = 0.613 and 0.611) and students (κ = 0.610 and 0.665). Pairwise inter-observer agreement was presented to be moderate to excellent between clinician and clinician (κ = 0.41~0.87, 0.43~0.81), moderate to excellent between student and student (κ = 0.43~0.71, 0.53~0.82), and poor to excellent between clinician and student (κ = 0.25~0.81, 0.35~0.87). Good to excellent intra-observer agreement (κ = 0.69~0.85) was presented for eight observers. However, no correlation was illustrated between years of experience and inter- or intra-observer agreement.

CONCLUSION

Judgment of TBS has a good overall inter-observer agreement and good to excellent intra-observer agreement, which guarantees its utilization and popularity in detecting OPMDs and oral cancer.

CLINICAL RELEVANCE

To our knowledge, this is the first study to investigate the inter- and intra-observer agreement of TBS judgment. The present results revealed a good inter-observer agreement and good to excellent intra-observer agreement, which provide a beneficial supplement to the knowledge of TBS technique.

Nanotechnology: a promising method for oral cancer detection and diagnosis

Oral cancer is a common and aggressive cancer with high morbidity, mortality, and recurrence rate globally. Early detection is of utmost importance for cancer prevention and disease management. Currently, tissue biopsy remains the gold standard for oral cancer diagnosis, but it is invasive, which may cause patient discomfort. The application of traditional noninvasive methods-such as vital staining, exfoliative cytology, and molecular imaging-is limited by insufficient sensitivity and specificity. Thus, there is an urgent need for exploring noninvasive, highly sensitive, and specific diagnostic techniques. Nano detection systems are known as new emerging noninvasive strategies that bring the detection sensitivity of biomarkers to nano-scale. Moreover, compared to current imaging contrast agents, nanoparticles are more biocompatible, easier to synthesize, and able to target specific surface molecules. Nanoparticles generate localized surface plasmon resonances at near-infrared wavelengths, providing higher image contrast and resolution. Therefore, using nano-based techniques can help clinicians to detect and better monitor diseases during different phases of oral malignancy. Here, we review the progress of nanotechnology-based methods in oral cancer detection and diagnosis.

Spectroscopic characterization of oral epithelial dysplasia and squamous cell carcinoma using multiphoton autofluorescence micro-spectroscopy

OBJECTIVE

Multiphoton autofluorescence microscopy (MPAM) has shown potential in identifying features that are directly related to tissue microstructural and biochemical changes throughout epithelial neoplasia. In this study, we evaluate the autofluorescence spectral characteristics of neoplastic epithelium in dysplasia and oral squamous cell carcinoma (OSCC) using multiphoton autofluorescence spectroscopy (MPAS) in an in vivo hamster model of oral neoplasia in order to identify unique signatures that could be used to delineate normal oral mucosa from neoplasia.

MATERIALS/METHODS

A 9,10-dimethyl-1,2-benzanthracene (DMBA) hamster model of oral precancer and OSCC was used for in vivo MPAM and MPAS. Multiphoton Imaging and spectroscopy were performed with 780 nm excitation while a bandpass emission 450-650 nm was used for MPAM. Autofluorescence spectra was collected in the spectral window of 400-650 nm.

RESULTS

MPAS with fluorescence excitation at 780 nm revealed an overall red shift of a primary blue-green peak (480-520 nm) that is attributed to NADH and FAD. In the case of oral squamous cell carcinoma (OSCC) and some high-grade dysplasia an additional prominent peak at 635 nm, attributed to PpIX was observed. The fluorescence intensity at 635 nm and an intensity ratio of the primary blue-green peak versus 635 nm peak, showed statistically significant difference between control and neoplastic tissue.

DISCUSSION

Neoplastic transformation in the epithelium is known to alter the intracellular homeostasis of important tissue metabolites such as NADH, FAD, and PpIX, which was observed by MPAS in their native environment. A combination of deep tissue microscopy owing to higher penetration depth of multiphoton excitation and depth resolved spectroscopy could prove to be invaluable in identification of cytologic as well as biomolecular spectral characteristic of oral epithelial neoplasia. Lasers Surg. Med. 49:866-873, 2017. © 2017 Wiley Periodicals, Inc.

The diagnostic performance parameters of Narrow Band Imaging: A preclinical and clinical study

OBJECTIVES

The oral carcinoma is a widespread pathology and still presents poor prognosis. Among the available procedures for its early detection, Narrow Band Imaging technique allows to assess potential vascular network abnormalities. The reliability of this technique in the detection of dysplastic and neoplastic oral lesions was evaluated in a preclinical and clinical study.

MATERIALS AND METHODS

In the preclinical study, a chemical oral carcinogen was administered to 50 mice to induct both dysplastic and neoplastic oral lesions. In the clinical study 91 patients, bearing suspicious premalignant and malignant oral lesions, have been included. Images of animals' and patients' lesions were acquired under white and Narrow Band Imaging light prior to biopsy. Two expert raters examined the images and classified lesions, which were eventually compared to the histological diagnosis. The diagnostic performance included sensitivity, specificity, positive likelihood ratio, positive and negative predictive values, accuracy, percentages and degree of agreement between raters' evaluation and the histological report.

RESULTS

In the preclinical study sensitivity ranged from 0.57 to 1, specificity from 0.85 to 0.99, positive likelihood ratio from 6.54 to 65.04, positive predictive values from 0.32 to 0.96, negative predictive values from 0.91 to 1 and accuracy from 0.86 to 0.98. In the clinical study sensitivity ranged from 0.63 to 0.99, specificity from 0.89 to 1, positive likelihood ratio from 8.45 to 61.47, positive predictive values from 0.59 to 0.96, negative predictive values from 0.78 to 1 and accuracy from 0.82 to 0.99.

CONCLUSION

Narrow Band Imaging is an accurate technique, which holds a great potential for tumour angiogenesis evaluation and for the subsequent early detection of suspicious premalignant and malignant oral lesions.