[Oral cytology: historical development, current status, and perspectives]

Clinical and cytological study of the oral mucosa of smoking and non-smoking qat chewers in Yemen

OBJECTIVE

The study was conducted to investigate the role of qat and smoking habits on the prevalence of visible and cytological abnormalities in the oral mucosa among Yemenites.

METHODS

We recruited 30 non-smoking and 30 smoking Yemenites chewing qat unilaterally for at least 5 years. We inspected oral cavities for the presence of lesions and took brush biopsies from the buccal mucosa/gingiva of the chewing/non-chewing region.

RESULTS

All visible oral lesions were flat and homogeneous, and cytological changes were detected frequently. Among both non-smokers and smokers, white lesions and cytological changes were detected in 77% of all cases. On the chewing area, the proportion with white lesions ranged--depending on anatomical area and smoking status--between 47 and 93% and was significantly more frequent than on the non-chewing side (range 3-47%). The proportion of regions with changes was similar in non-smokers and smokers. Kappa statistics for "interobserver" agreement between visual inspection and cytological specimens of brush biopsies was at best fair (≤0.25).

CONCLUSIONS

The high prevalence of visible lesions and cytological abnormalities among qat chewers was independent of smoking status.

CLINICAL RELEVANCE

The moderate level of agreement between visual inspection and exfoliative cytology demonstrates the still challenging clinical management of chronic qat chewers, though brush biopsies including adjuvant techniques like DNA cytometry may support the clinical decision-making process in future.

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

INTRODUCTION

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.

METHOD

We took 263 oral BBs from 200 patients with potentially malignant disorders.

RESULTS

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%.

DISCUSSION AND CONCLUSION

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.

Cytopathology: a useful technique for diagnosing oral lesions?: a systematic literature review

Oropharyngeal cancer is the 11th most common cancer worldwide. The diagnostic method of choice for oral cavity lesions is biopsy and pathological examination. Cytopathology is a simple and inexpensive method, but it is not yet widespread among dental professionals. The aim of this study was to evaluate the evidence for the effectiveness of cytopathology in diagnosing oral lesions. We conducted a systematic literature review of randomized clinical trials that compared the diagnostic accuracies of oral lesion cytology and histopathology. We used the following search terms: cytology, oral lesions, and oral cancer. The meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Between 1967 and 2010, there were 80 relevant articles in the literature, 14 of which were included in this study. The I-square for sensitivity was 80.2%, and the specificity value was 96.7%. The pooled sensitivity was 0.942 [95% confidence interval (CI): 0.926-0.955], and the pooled specificity was 0.970 (95% CI: 0.963-0.975). The area under the curve was 0.9901. Our study suggests that cytology has good sensitivity and specificity for the diagnosis of oral lesions and allows the use of other associated techniques, such as DNA analysis, which may improve the accuracy of cytology.

Non-computer-assisted liquid-based cytology for diagnosis of oral squamous cell carcinoma

The development of oral squamous cell carcinoma (OSCC) occasionally follows the neoplastic progression of other premalignant lesions. Although biopsy is the definitive diagnostic method, liquid-based cytology is an adequate method for screening suspicious lesions. We compared liquid-based cytology to histology for diagnosis of OSCC in patients with oral lesions that raised clinical suspicion of malignancy. Our sample consisted of 48 patients. Cytological samples were obtained by scraping the lesion superficially using Cytobrush®. We conducted cytological and histopathological evaluation of all preparations. We estimated sensitivity and specificity levels as well as positive and negative predictive values. The degree of inter-observer agreement for both methods was assessed using the kappa index. Twenty-eight (58.3%) of the cases finally were diagnosed with OSCC and 20 (41.7%) were determined to be premalignant lesions. We observed eight false negatives and no false positives; OSCC prevalence was 56.5%. The values for diagnostic indices were: sensitivity, 69% (CI 95%, prevalence 51.87); specificity, 100%; positive predictive value, 100%; negative predictive value, 71% (CI 95% 54.82). A kappa index of 0.622 (CI 95% 0.93, 0.39) was observed.

Techniques for precancerous lesion diagnosis

The development of the oral squamous cell carcinoma (OSCC) is a multistep process that requires the accumulation of multiple genetic alterations usually preceded by detectable mucosal changes, most often leukoplakias and erythroplakias. The clinical appearance of oral precancerous lesions and their degree of epithelium dysplasia suggests the malignization potential. Several techniques have been developed to improve the clinical and cytological diagnosis of oral precancerous lesions. The present paper reviews the main techniques used to improve premalignant lesion diagnosis.

Early detection in head and neck cancer - current state and future perspectives

Survival and quality of life in head and neck cancer are directly linked to the size of the primary tumor at first detection. In order to achieve substantial gain at these issues, both, primary prevention and secondary prevention, which is early detection of malignant lesions at a small size, have to be improved. So far, there is not only a lack in the necessary infrastructure not only in Germany, but rather worldwide, but additionally the techniques developed so far for early detection have a significance and specificity too low as to warrant safe implementation for screening programs. However, the advancements recently achieved in endoscopy and in quantitative analysis of hypocellular specimens open new perspectives for secondary prevention. Chromoendoscopy and narrow band imaging (NBI) pinpoint suspicious lesions more easily, confocal endomicroscopy and optical coherence tomography obtain optical sections through those lesions, and hyperspectral imaging classifies lesions according to characteristic spectral signatures. These techniques therefore obtain optical biopsies. Once a "bloody" biopsy has been taken, the plethora of parameters that can be quantified objectively has been increased and could be the basis for an objective and quantitative classification of epithelial lesions (multiparametric cytometry, quantitative histology). Finally, cytomics and proteomics approaches, and lab-on-the-chip technology might help to identify patients at high-risk. Sensitivity and specificity of these approaches have to be validated, yet, and some techniques have to be adapted for the specific conditions for early detection of head and neck cancer. On this background it has to be stated that it is still a long way to go until a population based screening for head and neck cancer is available. The recent results of screening for cancer of the prostate and breast highlight the difficulties implemented in such a task.

Exfoliative cytology for diagnosing oral cancer

Exfoliative cytology is a minimally invasive technique for obtaining oral cell specimens from patients for diagnostic purposes. Classical applications of oral cytology studies, such as oral candidiasis, have been extended to include oral precancerous and cancerous lesions. A number of analytical methods are available for studying cytology specimens. The development of molecular analysis techniques, the oral cancer etiopathogenic process, and improvements in liquid-based exfoliative cytology are leading to renewed interest in exfoliative cytology. Results sometimes are disputed, so the aim of our review was to clarify the applicability of exfoliative cytology to the diagnosis of oral precancerous and cancerous lesions.

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.

[Performance of conventional oral brush biopsies]

BACKGROUND

This study evaluated the performance of oral brush biopsies using standard morphological analysis and haematoxylin and eosin (HE) staining for detecting oral squamous cell carcinomas and their respective precursor lesions

PATIENTS AND METHODS

Brush biopsies were obtained in 169 consecutive patients who underwent routine biopsies and histological examination for clinically suspicious oral lesions. Air-dried smears were processed by acetone fixation and HE staining. Cytological assessment used well-established criteria of atypia to classify the specimen as either "tumor negative" (no signs of atypia, no malignant cells) or "tumor positive" (malignant cells, any sign of atypia or doubtful cells).

RESULTS

Despite a sufficient number of cells, a definite cytological diagnosis could not be established in six cases. According to the criteria specified above, these specimens were classified as "tumor positive." The cytological analysis identified 49 out of 62 oral malignancies (sensitivity 79%). Seven out of 107 benign lesions were classified as false positive (specificity 93%). The positive and negative predictive values were each 88%.

CONCLUSION

Oral brush biopsies will identify only about 80% of oral malignancies when the smears are processed by routine HE stains and are analysed via standard morphological criteria. Thus, this technique should not be used for diagnostic proof or to exclude malignant cells in a lesion suspicious for cancer. However, oral brush biopsy provides a versatile back-up strategy to uncover the true nature of the disease if a lesion is clinically considered benign by mistake.

[Identification of a recurrent oral squamous cell carcinoma by brush cytology]

BACKGROUND

Large oral lesions comprise the risk that an incisional biopsy does not reveal the most aggressive site in spite of carefully selecting the place of biopsy.

CASE REPORT

The first incisional biopsy of a large, clinically suspect, oral lesion could not identify the subepidermal spread of a recurrent oral squamous cell carcinoma. Atypical cells obtained by a simultaneous brush biopsy prompted a renewed, incisional biopsy which finally established the diagnosis of a recurrent, oral squamous cell carcinoma.

CONCLUSIONS

The presented case emphasizes the value of brush biopsy in the follow-up of oral squamous cell carcinoma, especially in examination of oral lesions covering a large area.