Oral CDx Research Articles

No role for human papillomavirus infection in oral cancers in a region in southern India.

Oral cancer is a major public health issue in India with ∼ 77,000 new cases and 52,000 deaths yearly. Paan chewing, tobacco and alcohol use are strong risk factors for this cancer in India. Human papillomaviruses (HPVs) are also related to a subset of head and neck cancers (HNCs). We examined the association between oral HPV and oral cancer in a sample of Indian subjects participating in a hospital-based case-control study. We recruited incident oral cancer cases (N = 350) and controls frequency-matched by age and sex (N = 371) from two main referral hospitals in Kerala, South India. Sociodemographic and behavioral data were collected by interviews. Epithelial cells were sampled using Oral CDx® brushes from the oral cancer site and the normal mucosa. Detection and genotyping of 36 HPV genotypes were done using a polymerase chain reaction protocol. Data collection procedures were performed by qualified dentists via a detailed protocol with strict quality control, including independent HPV testing in India and Canada. HPV DNA was detected in none of the cases or controls. Associations between oral cancer and risk factors usually associated with HPV infection, such as oral sex and number of lifetime sexual partners, were examined by logistic regression and were not associated with oral cancer. Lack of a role for HPV infection in this study may reflect cultural or religious characteristics specific to this region in India that are not conducive to oral HPV transmission. A nationwide representative prevalence study is needed to investigate HPV prevalence variability among Indian regions.

Transepithelial Brush Biopsy – Oral CDx® – A Noninvasive Method for the Early Detection of Precancerous and Cancerous Lesions

The Oral CDx® brush biopsy (BB) method is a computer-assisted sample analysis that detects abnormal cells in all cell layers of the epithelium of the oral mucosa. We took 263 oral BBs from 200 patients with potentially malignant disorders. We received 204 negative results and 39 atypical, 7 positive and 13 inadequate results. SBs were taken in 56 cases. Therefore, the sensitivity for the detection of abnormal cells was 90% and the specificity was 44.1%. The positive predictive value accounted for 47.2% and the NPV accounted for 88.2%. For the results of sensitivity and specificity of the Oral CDx® BB, there is still space for improvement but they are already high. Additional methods like DNA-image cytometry may enhance the results. But it is a simple and noninvasive method which does not need a special effort either from the patient or from the clinicians.

The Application of Vizilite in Oral Cancer

This article depicts the various applications of Vizilite plus in oral cancer. The oral cavity demonstrates a variety of red and white, pigmented and vesiculo- bullous lesions. Oral cancer still happens to carry the highest mortality worldwide, especially in India. In India, the prime focus is on the downstreaming of oral cancer from an advanced stage to an early diseased state. The techniques that are promoted to facilitate an earlier detection and diagnosis of an oral malignancy include Toluidine blue, ViziLite Plus with TBlue, ViziLite, Microlux DL, Orascoptic DK, VEL scope, Oral CDx and brush biopsy.

Liquid-based cytology in oral cavity squamous cell cancer

Oral exfoliative cytology is a practical tool for early diagnosis of squamous cell carcinoma (OSCC) and potentially malignant lesion (OPML), but is not yet extensively used. A literature review evaluated conventional and liquid-based oral diagnostic cytology efficacy and efficiency. 'Special' techniques like liquid-based cytology, computer-assisted cytology, Oral CDx, DNA ploidy, immunocytochemistry, molecular analyses and microhistology were reviewed. Cytology was useful when diagnosing OSCC and OPML. Oral CDx may assess dysplastic changes in clinically suspicious (class I) lesions, with doubtful efficacy in apparently innocuous (class II) lesions. Flow and/or image cytometry and immunocytochemistry can identify markers for the prediction of evolution of the OPML to OSCC. Molecular biology can detect the minimal residual clonal population of cancer cells in field cancerization and oral mucosa surgical margins. Microhistology is a reliable first level test in class II lesions for selected cases requiring surgical biopsy. Conventional cytology helps in OSCC and OPML screening; liquid-based cytology gives better results, enhancing both sensitivity and specificity, and provides material for further investigation. Sampling with the 'curette technique' permits collection of 'accidental' tissue fragments used as microbiopsies and proved a useful first-level test for the management of class II OPML.

Comparison of the Cytobrush®, dermatological curette and oral CDx® brush test as methods for obtaining samples of RNA for molecular analysis of oral cytology

Interest in oral exfoliative cytology has increased with the availability of molecular markers that may lead to the earlier diagnosis of oral squamous cell carcinoma. This research aims to compare the efficacy of three different instruments (Cytobrush, curette and Oral CDx brush) in providing adequate material for molecular analysis. One hundred and four cytological samples obtained from volunteer healthy subjects were analysed using all three instruments. The clinical and demographical variables under study were age, sex and smoking habits. The three instruments were compared for their ability to obtain adequate samples and for the amount of RNA obtained using quantitative real-time polymerase chain reaction (PCR-qRT) analysis of the Abelson (ABL) housekeeping gene. RNA of the ABL gene has been quantified by number of copies. Adequate samples were more likely to be obtained with a curette (90.6%) or Oral CDx (80.0%) than a Cytobrush (48.6%); P < 0.001. Similarly, the RNA quantification was 17.64 ± 21.10 with a curette, 16.04 ± 15.81 with Oral CDx and 6.82 ± 6.71 with a Cytobrush. There were statistically significant differences between the Cytobrush and curette (P = 0.008) and between the Cytobrush and OralCDx (P = 0.034). There was no difference according to the demographical variables. Oral exfoliative cytology is a simple, non-invasive technique that provides sufficient RNA to perform studies on gene expression. Although material was obtained with all three instruments, adequate samples were more likely to be obtained with the curette or Oral CDx than with a Cytobrush. The Oral CDx is a less aggressive instrument than the curette, so could be a useful tool in a clinical setting.

Comparison of three sampling instruments, Cytobrush, Curette and OralCDx, for liquid-based cytology of the oral mucosa

Exfoliative cytology of the oral cavity is a simple and noninvasive technique that permits the study of epithelial cells. Liquid-based cytology is an auxiliary diagnostic tool for improving the specificity and sensitivity of conventional cytology. The objective of our study was to compare the quality of normal oral mucosa cytology samples obtained using three different instruments, Cytobrush®, dermatological curette and Oral CDx® for liquid-based cytology. One hundred four cytological samples of oral cavity were analyzed. Samples were obtained from healthy volunteer subjects using all three instruments. The clinical and demographic variables were age, sex and smoking habits. We analyzed cellularity, quality of the preparation and types of cells in the samples. All preparations showed appropriate preparation quality. In all smears analyzed, cells were distributed uniformly and showed no mucus, bleeding, inflammatory exudate or artifacts. We found no correlation between the average number of cells and the type of instrument. The samples generally consisted of two types of cells: superficial and intermediate. No differences were found among the cytological preparations of these three instruments. We did not observe basal cells in any of the samples analyzed.

Assessing the usefulness of three adjunctive diagnostic devices for oral cancer screening: a probabilistic approach

Visually distinguishing oral cancer from noncancerous oral lesions is problematic. Currently, commercial diagnostic devices are being marketed to dentists as effective screening devices to use in general practice. The purpose of this study is to evaluate the probabilistic performance of VELscope®, Oral CDx® and toluidine blue staining as clinical adjunctive diagnostic procedures in routine screening for oral cancer in dental practice. Sensitivity and specificity information for each device was taken from the literature. The positive predictive value (PPV) and false positive rate, based on three clinical screening scenario, were calculated using Bayes' Theorem. Under three clinical scenarios (screening the general population, screening only adults (≥40 years) and screening adults (≥40 years) that present with intra-oral visible lesions), VELscope produced the highest PPV's of 1.27%, 2.53% and 8.11%, respectively. This indicates a false positive rate of between 91.89% and 98.73%. VELscope, OralCDx and toluidine blue staining have high false positive rates when they are used to screen routinely for oral cancer. It would be inefficient to allocate scarce healthcare resources to the routine use of these devices for oral cancer screening. These devices may be beneficial in opportunistic screening programmes or in cancer referral clinics when the pretest probability of oral cancer is likely to be above 10%. Further research is needed to determine at which pretest probabilities these adjunctive diagnostic devices would be cost-beneficial for the screening of oral cancer.

O165. Comparing the performance of quantitative cytology versus the oral CDX Brush Test ®

O165. Comparing the performance of quantitative cytology versus the oral CDX Brush Test ®

O166. Lab-on-a-chip sensor for analysis of cellular biomarkers in oral exfoliative cytology: A new diagnostic tool for early detection of oral cancer

Introduction: Analysis of cytological samples from potentially malignant oral lesions (PMOLs) can be of diagnostic and possibly prognostic value to the clinician. Objective: To compare the performance, on cytological samples procured from subjects with known SCCA or PMOLs, of quantitative cytology (Perceptronix, Canada) versus the Oral CDX Brush Test (CDX, USA) against matched histopathology (‘‘gold standard”). Methods: Subjects with known SCCA or PMOLs (categorized into low or high risk of clinical suspicion) underwent an oral brush biopsy, whereupon a cytological sample was plated and fixed. Instead of discarding the brushes, the tips with residual cells were retained and fixed. Unless a known SCCA, a scalpel biopsy was immediately performed at the brush site and tissue sent for histopathology. Glass slides were sent to CDX for modified Papanicolaou staining and automated cytological analysis, and reported by a cytopathologist as normal (CDX negative) or abnormal (CDX positive or atypical). Leftover brushes were sent to Perceptronix, cytospun, underwent Feulgen-Thionin staining, and DNA ploidy analysis using the ClearCyte automated image cytometry system. Galleries containing nuclei with non-diploid DNA content were reviewed by a cytopathologist, and reported as normal or abnormal. Results: A total of 86 cytological samples were of sufficient yield to undergo both tests. Of these samples, 57 (66%) had a diagnosis of dysplasia or SCCA. Compared with the ‘‘gold standard”, the sensitivity/specificity/PPV/NPV of quantitative cytology versus the Brush Test in detecting dysplasia (any grade) or SCCA were 61/100/100/ 57% versus 77/83/90/65%, respectively. Overall performance increased on high risk suspicion PMOLs and when detecting higher grade dysplasias or SCCA. Quantitative cytology had additional value in resolving CDX atypical results. Conclusion: Each test offers an advantage and disadvantage over the other. Longitudinal studies are needed to assess the utility of such tests in low risk PMOLs or low grade dysplasias. Funded by NYUCD Dean’s Student Research Award & NIDCR/NIH Grant # U54-DE14257.

Oral cytology revisited

During the last decade, oral cytology has once again become the focus of scientific research. This new interest is due to the introduction of a cytobrush for cell collection as well as a computer-assisted analysis (Oral CDx). Although promising, the sensitivity and specificity of conventional oral brush cytology remains limited. To circumvent the problems and improve the accuracy, various adjunctive analytical methods have been attempted. DNA analysis, immunocytochemical and molecular analysis are suggested methodological cytology approaches to improve the validity of oral brush cytology. An increase in sensitivity (up to 100%) and specificity (up to 100%) of oral brush biopsy has been reported on localized pre-malignant and malignant lesions. Oral brush biopsy probably will not replace histopathology in the definitive diagnosis of oral cancer, but it might be valuable for the prevention of misdiagnosis of clinically doubtful oral lesions and for the monitoring of lesions that might proceed on to oral cancer.

Adjunctive Techniques for Oral Cancer Examination and Lesion Diagnosis: A Systematic Review of the Literature

Adjunctive techniques that may facilitate the early detection of oral premalignant and malignant lesions (OPML) have emerged in the past decades. The authors undertook a systematic review of the English-language literature to evaluate the effectiveness of toluidine blue (TB), ViziLite Plus with TBlue (Zila Pharmaceuticals, Phoenix), ViziLite (Zila Pharmaceuticals), Microlux DL (AdDent, Danbury, Conn.), Orascoptic DK (Orascoptic, a Kerr Company, Middleton, Wis.), VELscope (LED Dental, White Rock, British Columbia, Canada) and OralCDx (Oral CDx Laboratories, Suffern, N.Y.) brush biopsy. They abstracted data relating to study design, sampling and characteristics of the study group, interventions, reported outcomes and diagnostic accuracy of adjunctive aids from 23 articles meeting inclusion and exclusion criteria, including availability of histologic outcomes. The largest evidence base was for TB. A limited number of studies was available for ViziLite, ViziLite Plus with TBlue and OralCDx. Studies of VELscope have been conducted primarily to assess the margins of lesions in known OPML. The authors identified no studies of Microlux DL or Orascoptic DK. Study designs had various limitations in applicability to the general practice setting, including use of higher-risk populations and expert examiners. There is evidence that TB is effective as a diagnostic adjunct for use in high-risk populations and suspicious mucosal lesions. OralCDx is useful in assessment of dysplastic changes in clinically suspicious lesions; however, there are insufficient data meeting the inclusion criteria to assess usefulness in innocuous mucosal lesions. Overall, there is insufficient evidence to support or refute the use of visually based examination adjuncts. Practical Implications. Given the lack of data on the effectiveness of adjunctive cancer detection techniques in general dental practice settings, clinicians must rely on a thorough oral mucosal examination supported by specialty referral and/or tissue biopsy for OPML diagnosis.

Efficacy of the ViziLite System in the Identification of Oral Lesions

Early detection of oral cancer is crucial in improving survival rate. To improve early detection, the use of a dilute acetic acid rinse and observation under a chemiluminescent light (ViziLite; Zila Pharmaceuticals, Phoenix, AZ) has been recommended. However, to date, the contributions of the individual components of the system have not been studied. The present study was done to investigate the efficacy of the individual components of the ViziLite system in providing improved visualization of early oral mucosal lesions. A total of 100 patients, 39 males and 61 females, age 18 to 93 years (mean age, 44 years), who presented to the Virginia Commonwealth University School of Dentistry for dental screening were examined. There were 58 Caucasians, 29 African-Americans, 5 Hispanics, 6 Asians, and 2 of mixed ethnicity. Thirty-five patients smoked, 53 used alcohol, and 25 both smoked and drank. After written consent, the oral cavity was examined under incandescent light for soft tissue abnormalities. After 1-minute rinse with 1% acetic acid, the mouth was re-examined for additional mucosal abnormalities. Then, the mouth was examined once again using the ViziLite system's chemiluminescent light. Any lesions detected by these 3 examinations that were clinically undiagnosable were brush biopsied (Oral CDx) for determination of cellular representation. In the original examination of the 100 patients, 57 clinically diagnosable benign lesions (eg, linea alba, leukoedema) and 29 clinically undiagnosable lesions were detected. After the rinse, 6 additional diagnosable lesions (linea alba) and 3 undiagnosable lesions were found. No additional lesions were detected with the chemiluminescent light. Of the 32 undiagnosable lesions that were brush biopsied, 2 were positive for atypical cellular characterization and warranted further investigation with a scalpel biopsy. Neither of these lesions was found to be premalignant or malignant. Although the acid rinse accentuated some lesions, the overall detection rate was not significantly improved. The chemiluminescent light produced reflections that made visualization more difficult and thus was not beneficial.