DNA content status using brush biopsy with image cytometry correlated with staging of oral leukoplakia: a preliminary study

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.

Continuous artificial intelligence-assisted DNA aneuploidy cytology for surveilling dysplastic oral leukoplakia treated by photodynamic therapy

Oral leukoplakia (OLK) is one of the most common potentially malignant disorders. High-risk lesions require early intervention before developing into oral cancer. Photodynamic therapy (PDT) is a noninvasive technique for premalignant lesions. Scalpel biopsy remains a reliable method for monitoring the prognosis of OLK, but it is an invasive procedure with poor reproducibility to suspicious lesions. DNA aneuploidy cytology by oral cytobrush has been proposed as a promising objective and noninvasive tool in screening and diagnosing premalignant and malignant lesions. Here, we discussed the significance of artificial intelligence (AI)-assisted DNA aneuploidy cytology by image cytometry (DNA-ICM) for surveilling non-homogeneous OLK with moderate-to-severe dysplasia that was treated by 5-aminolevulinic acid-mediated PDT (ALA-PDT). The present study provides a scheme of the sequential management and surveillance strategy for OLK.

Development and validation of a risk model for noninvasive detection of cancer in oral potentially malignant disorders using DNA image cytometry

OBJECTIVE

To elucidate whether DNA aneuploidy was an independent discriminator for carcinoma within oral potentially malignant disorders (OPMDs), and further establish and validate a risk model based on DNA aneuploidy for the detection of oral cancer.

METHODS

A total of 810 consecutive patients with OPMD were prospectively enrolled from March 2013 to December 2018, and divided into a training set (n = 608) and a test set (n = 202). Brushing and biopsy samples from each patient were processed by DNA-DNA image cytometry and histopathological examination, respectively.

RESULTS

DNA aneuploidy of an outside DNA index ≥ 3.5 in OPMD was an independent marker strongly associated with malignant risk [adjusted odds ratio: 13.04; 95% confidence interval (CI): 5.46-31.14]. In the training and test sets, the area under the curve (AUC) was 0.87 (95% CI: 0.82-0.91) and 0.77 (95% CI: 0.57-0.97), respectively, for detecting carcinoma in OPMD patients. The independent risk factors of lateral/ventral tongue and non-homogenous type combined with a risk model built with a multivariate logistic regression revealed a more favorable diagnostic efficacy associated with the training set (AUC: 0.93; 95% CI: 0.91-0.96) and test set (AUC: 0.94; 95% CI: 0.90-0.98). The sensitivity and specificity of carcinoma detection within OPMD was improved to 100% and 88.1%, respectively.

CONCLUSIONS

This large-scale diagnostic study established a risk model based on DNA aneuploidy that consisted of a noninvasive strategy with lateral/ventral tongue and non-homogenous features. The results showed favorable diagnostic efficacy for detecting carcinoma within OPMD, irrespective of the clinical and pathological diagnoses of OPMD. Multicenter validation and longitudinal studies are warranted to evaluate community practices and clinical applications.

Aneuploidy and loss of heterozygosity as risk markers for malignant transformation in oral mucosa

The ability to predict malignant transformation in oral potentially malignant disorders would inform targeted treatment, provide prognostic information and allow secondary prevention. DNA ploidy and loss of heterozygosity assays are already in clinical use, and loss of heterozygosity has been used in prospective clinical trials. This review appraises published evidence of predictive ability and explores interpretation of heterogeneous studies, with different diagnostic methods, criteria and intention. Both methods have a sound biological foundation and have predictive value independent of dysplasia grading and clinical parameters. The application of these two techniques cannot be directly compared because of differences in expression of results and application to populations of different risk. Predicting malignant transformation accurately on an individual patient basis is not yet possible with either technique. However, they are valuable applications to stratify patients for inclusion in trials, identify the lowest risk patients and exclude risk when biopsy results are indeterminate for dysplasia.

Profiling risk factors of micro-invasive carcinoma within oral potentially malignant disorders: a cross-sectional study

OBJECTIVES

To investigate the clinicopathological profile and risk factors of micro-invasive carcinoma within oral potentially malignant disorders (OPMD).

METHODS

Micro-invasive carcinomas were identified in a large prospective series of OPMD patients (n = 810) from eastern China. Logistic regression was applied to evaluate odds ratios (OR) with 95% confidence interval (CI) for indicative of malignant risk in general OPMD.

RESULTS

Leukoplakia (41.4%), lichen planus (28.0%), and lichenoid lesion (23.7%) were the most 3 clinical subtypes of OPMD. A total of 62 (7.7%) micro-invasive carcinomas within OPMD were identified, and 96.8% of micro-invasive carcinoma was found within leukoplakia and erythroplakia. Multivariate regression analysis revealed that the risk of malignant change within OPMD located on lateral/ventral tongue (OR, 15.1; 95% CI, 1.85-122.8; P = 0.011) was higher than other sites. The risk of malignant change within non-homogenous type (OR, 103.3; 95% CI, 13.39-796.7; P < 0.001) was strikingly higher than other subtypes of OPMD, respectively. Intriguingly, the risk of micro-invasive carcinoma diagnosed in current smoker (OR, 3.96; 95% CI, 1.31-12.02; P = 0.015) was higher than non-smoker.

CONCLUSION

This large-scale cross-sectional study elucidated the clinical factors and risk assessment of micro-invasive carcinoma within OPMD.

CLINICAL RELEVANCE

Non-homogenous lesions located on lateral/ventral tongue might be monitored at closer intervals, and the need for rigorous management to detect malignant changes.

A Comparative Study of Liquid-Based Cytology and DNA Image Cytometry in the Diagnosis of Serous Effusion

Background:

Liquid-based cytology is one of the most useful methods to diagnose a patient with serous effusion, especially when malignancy is suspected. As an alternative to the use of liquid-based cytology only, the serous effusion can be further processed using the technique of DNA image cytometry, which may augment diagnostic utility. The aim of this study was to compare the diagnostic yields of liquid-based cytology, DNA image cytometry, and both in combination, regardless of serous-effusion etiology.

Methods:

We conducted a descriptive study on patients with serous effusions from July 2016 to June 2018. All samples were submitted for liquid-based cytology and DNA image cytometry techniques. We compared the results of cytopathological studies to the final diagnoses.

Results:

For a total of 798 samples, final diagnoses included 412 (51.6%) malignancies, 280 (35.1.%) inflammatory diseases, and 106 (13.3%) transudative serous effusions. Liquid-based cytology had a more sensitive diagnostic yield than DNA image cytometry did (38.8% vs 30.7%; P < .05), but the combination of both had a higher yield (43.7%; P < .05) compared with that of liquid-based cytology alone. For the 412 malignant serous effusions, diagnostic yields of liquid-based cytology and DNA image cytometry were 73.8% and 59.5%, respectively. The difference in sensitivity was significant (P < .05). Combined liquid-based cytology + DNA image cytometry improved diagnostic yield to 83.3% (P < .05). However, both liquid-based cytology and DNA image cytometry had low diagnostic yields for inflammatory diseases and transudative serous effusions.

Conclusion:

In serous effusion, liquid-based cytology’s diagnostic performance is better than that of DNA image cytometry. Application of both techniques can significantly increase diagnostic yield.

DNA aneuploidy with image cytometry for detecting dysplasia and carcinoma in oral potentially malignant disorders: A prospective diagnostic study

BACKGROUND

Current evidence on diagnostic value of aneuploidy with DNA image cytometry (ICM) using brushings for oral potentially malignant disorders (OPMD) is limited by sample size and inconsistent classification criteria of aneuploidy. This study aimed to explore the optimal cut-off values of DNA content and evaluate the diagnostic accuracy of DNA-ICM for detecting dysplasia and/or carcinoma in OPMD.

MATERIALS AND METHODS

A total of 401 consecutive patients with OPMD were enrolled in this prospective diagnostic study. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination respectively.

RESULTS

When the optimal cut-off of at least one aneuploid cell with DNA index (DI) ≥2.3, the area under the curves (AUC) was 0.735 and positive predictive value was 92.7% for detecting dysplasia within OPMD. When the optimal cut-off of at least one aneuploid cell with DI ≥ 3.5, the AUC was 0.851 and negative predictive values was 96.8% for detecting carcinoma within OPMD. Importantly, multivariate analysis revealed that aneuploidy with DI ≥ 2.3 in OPMD was significantly associated with dysplasia risk (adjusted OR, 5.52; 95%CI, 2.90-10.51; P < .001), and aneuploidy with DI ≥ 3.5 in OPMD was strongly associated with malignant risk (adjusted OR, 21.05; 95%CI, 9.34-47.41; P < .001).

CONCLUSIONS

This largest-scale diagnostic study optimized the criteria of aneuploidy cytology for noninvasive detection of oral dysplasia and carcinoma within OPMD. DNA aneuploidy in OPMD was an independent marker that strongly associated with oral dysplasia/carcinoma. Our findings suggest that DNA-ICM may serve as a useful noninvasive adjunctive tool for oral cancer and OPMD screening.

DNA content abnormality in oral submucous fibrosis concomitant leukoplakia: A preliminary evaluation of the diagnostic and clinical implications

Oral submucous fibrosis (OSF) is an insidious chronic oral and oropharyngeal potentially malignant disorder. Our previously studies reported that DNA image cytometry (ICM) using brushing added in the diagnosis of high-grade dysplasia and staging of oral leukoplakia (OLK). This preliminary study aimed to investigate the abnormal rate of DNA content in 30 cases of OSF including three cases of OSF concomitant OLK and evaluate their the diagnostic and clinical implications with special emphasis on the OSF concomitant OLK. Brushing and biopsy sample form each patient was processed by DNA-ICM and histological examination, respectively. The results of DNA-ICM analysis showed that all the lesions from the 27 patients with OSF only were identified as normal DNA content. Strikingly, two of three cases of OSF concomitant OLK were identified as abnormal DNA content, and one case of whom progressed to early oral squamous cell carcinoma at the follow-up of 31 months. Collectively, this preliminary evaluation revealed that DNA content abnormality was hardly observed in OSF only; however, it may be usually observed in OSF concomitant OLK, whom should be monitored on a priority basis for early detection of carcinoma. Multicenter large studies are needed to validate the findings of the current study.

The role of DNA image cytometry in screening oral potentially malignant lesions using brushings: A systematic review

It is believed that the majority of oral cancers develop from oral potentially malignant lesions (OPML). Though they can be easily detected during screening, risk stratification is difficult. During screening clinicians often find it difficult to distinguish OPMLs from benign lesions, and predicting OPML at risk of malignant transformation is particularly challenging. DNA aneuploidy has been known to be a marker of malignancy in a number of sites including the oral cavity. We performed a systematic review to evaluate the effectiveness of DNA-ICM using brushings in differentiating OPMLs from benign/inflammatory lesions during screening and in predicting malignant transformation. MEDLINE, Pubmed, EMBASE electronic databases were systematically searched using a combination of keywords and subject headings. A total of 11 articles satisfied our inclusion criteria. These studies reported a wide range of sensitivity (16-96.4%) and specificity (90-100%) due to the differences in study design, definitions of high risk or low risk lesions and DNA-ICM protocol used. No long-term longitudinal studies were identified to assess the role of DNA-ICM using brushings in predicting malignant transformation. No studies evaluated the role of DNA-ICM in community screening settings. A number of studies combined DNA-ICM with other techniques like cytology or argyrophilic nucleolar organizer region counts leading to improved test results. In spite of DNA aneuploidy being accepted as a marker of malignancy, there is limited evidence of DNA-ICM using brushings being successful as an adjunct oral cancer screening tool. Longitudinal studies and large community screening studies need to be undertaken to draw stronger conclusion.

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.

[DNA cytometry of exfoliated cells in the diagnosis of oral potential malignant disorders]

OBJECTIVE

To evaluate the diagnostic efficiency of oral mucosa disease, especially oral squamous cell carcinoma (OSCC) and oral potential malignant disorders (OPMDs) by DNA cytometry compared with histopathological diagnosis, so as to find a convenient, simple and low-invasive method for screening and follow-up.

METHODS

203 subjects with OSCC, OPMDs and other oral mucosa disease without dysplasia according to the inclusion criteria and exclusion criteria were recruited from Peking University School and Hospital of Stomatology. The mean age was (52.44±13.55) years, 98 males and 105 females. Brush biopsy was taken before scalpel biopsy at the same site. The brush biopsy sample was screened by moticytometer system for DNA cytometry after Feulgen stain, and histopathological examination were taken for the scalpel tissue. Data from DNA cytometry were used to calculate the parameters, such as sensitivity, specificity, positive and negative predictive values, odds ratios, Youden index (YI), positive and negative likelihood ratios, compared with the golden standard, histopathological diagnosis. DNA cytometry and histopathological diagnosis were performed back to back.

RESULTS

Totally, 42 OSCC and 4 tumor in situ (TIS), 39 oral leukoplakia (OLK) with dysplasia (17 mild dysplasia, 13 medium dysplasia and 9 severe dysplasia), 29 OLK with hyperplasia, 1 verrucous OLK, 83 oral lichen planus (OLP) and 5 inflammation were included in our research. We grouped the OSCC, TIS and dysplasia as the positive group and others without dysplasia as the negative group, the sensitivity of DNA cytometry was 79.07%, the specificity was 81.20%, and the diagnostic accuracy was 80.30%,We grouped the OSCC and TIS as the tumor group, OLP, OLK with hyperplasia and inflammation as the non-tumor group, The sensitivity of DNA cytometry in diagnosing OSCC and TIS was 95.65%, and the specificity was 81.2%, The diagnostic accuracy was 85.28%. positive predictive values 66.67%, negative predictive values 97.94%, ratio odds 95, positive likelihood ratio 5.09, negative likelihood ratio 0.05, and Youden index 0.77. For the dysplasia, we grouped the different dysplasia together as the dyaplasia group, OLP, OLK with hyperplasia and inflammation as the non-tumor group, the sensitivity of DNA cytometry in diagnosing dyaplasia is 60%, the specificity is 81.2%. The diagnostic accuracy is 75.8%, positive predictive values 52.17%, negative predictive values 85.59%, ratio odds 6.48, positive likelihood ratio 3.19, negative likelihood ratio 0.49, and Youden index 0.41.

CONCLUSION

DNA cytometry is convenient and low-invasive, which can be used as an adjuvant method for screening the early OSCC and OPMDs, monitoring the prognosis of OSCC after surgery. Further large-scale and long period prospective studies are necessary to validate the better value of DNA cytometry.

Individualized five-year risk assessment for oral premalignant lesion progression to cancer

OBJECTIVE

The standard of care for premalignant lesion risk assessment is dysplasia grading by histopathology. With significant overlap between dysplasia grades and high inter- and intraobserver variations, histopathology dysplasia grading alone is not a useful prognostic tool. Our aim is to investigate whether a method for quantitatively assessing S100A7, a prognostic biomarker, using image analysis can better predict clinical outcome in cases with oral dysplasia.

STUDY DESIGN

Using the Visiopharm image analysis system, we analyzed a cohort of 150 oral biopsy samples to build and test Straticyte, a model for individualized assessment of the 5-year risk of progression of oral precancerous lesions to invasive squamous cell carcinomas.

RESULTS

Straticyte classified lesions more accurately than histopathological dysplasia grading for risk to progression to cancer over the following 5 years. The sensitivity of low-risk versus intermediate- and high-risk Straticyte groups was 95% compared to 75% for mild versus moderate and severe dysplasia. Furthermore, the negative predictive value for low-risk versus intermediate- and high-risk Straticyte groups was 78% compared to 59% for mild versus moderate and severe dysplasia.

CONCLUSION

By quantitatively assessing S100A7, Straticyte better defines the risk for developing oral squamous cell carcinoma than histopathological dysplasia grading alone.