Feulgen microspectrophotometry of oral cancer and leukoplakia

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.

Quantitative Exfoliative Cytology of Abnormal Oral Mucosal Smears

In this study quantitative techniques have been applied to smears collected from the buccal mucosa and floor of the mouth. The results display an encouraging success rate for identifying premalignant and malignant lesions. ‘Intrapatient’ normal smears provide a satisfactory control for comparison with pathological smears. Early results indicate that quantitative cytology could be of great value for monitoring and follow-up of suspicious lesions and provide an excellent additional diagnostic test for detecting early oral malignancy.

Nuclear features in different grades of epithelial dysplasia in leukoplakia: A computer assisted microscopic study

Context:

Abnormalities in nuclear morphology are very frequently seen in dysplasia, such as nuclear area, diameter, shape, number of nucleoli and membrane outline. The purpose of this study was to observe and compare the nuclear features in different grades of epithelial dysplasia in leukoplakia and to evaluate the use of Feulgen stain for observing the nuclear features in oral epithelial dysplasia in leukoplakia. Seventy paraffin embedded tissue section (20 mild, 20 moderate, 20 severe dysplasia cases and 10 control specimens) were analyzed for nuclear morphology using Feulgen stain under trinocular research microscope. Statistically significant results were obtained with P > 0.001, when intergroup comparison was done except in case of nuclear area and diameter between mild and moderate dysplasia. Nuclear features reflect cell's biological potential and its morphometry was found to be a useful tool for differentiating different grades of dysplasia.

Correlation between histological grading and ploidy status in potentially malignant disorders of the oral mucosa: A flow cytometric analysis

Background:

Histopathological grading of oral dysplastic lesions is the method of choice for evaluating malignant and potentially malignant disorders. Owing to inter- and intra-observer variability, determination of the DNA ploidy status of lesions may serve as an adjunct in the prediction of malignant transformation.

Aim:

To correlate histopathological grading and ploidy status in potentially malignant and malignant disorders of the oral mucosa.

Settings and Design:

A pilot study was done with 30 patients (10 patients with oral potentially malignant disorders predominantly leukoplakia, 10 patients with oral malignant lesions and 10 patients with normal mucosa).

Materials and Methods:

Incisional biopsy was done after isolating the biopsy site with 1% Toluidine blue staining. Two sections of the tissue were removed and sent for histopathological and Flow-cytometric analysis respectively. Histopathological diagnosis was obtained and compared with Flow-cytometric results which were graded as diploid and aneuploid. Further, the S – phase fraction, DNA index were also calculated to evaluate the severity of malignant transformation or malignancy.

Statistical Analysis:

The results were analyzed using Pearson Chi-Square Test.

Results:

There exists a significant correlation between histopathology and ploidy status in both potentially malignant and malignant group. (P = 0.002).

Conclusion:

The data from this study has shown that DNA Ploidy analysis can be used as a valuable tool in assessing the carcinomatous progression of potentially malignant and malignant lesions.

Nuclear features in oral squamous cell carcinoma: A computer-assisted microscopic study

Background and Objectives:

Oral squamous cell carcinoma (OSCC) is one of the most common tobacco-related cancers affecting the Indian population. Various malignancy-grading systems based on different histopathological features have been proposed for OSCC. Due to inherent subjectivity, inter-observer variation and reproducibility of a grading system remains a problem. Grading systems based on nuclear morphometry have been proposed for laryngeal, renal and pharyngeal carcinomas. In this study, an attempt was made to grade oral OSCC based on computer-assisted microscopic evaluation of nuclear features. Our intention was also to evaluate the use of Feulgen stain for studying nuclear features.

Materials and Methods:

Sections made from buccal mucosa biopsies of normal mucosa as well as different grades OSCC were stained by Feulgen reaction. The nuclear features were evaluated by computer-assisted microscopic image analysis for nuclear area (NA), nuclear perimeter (NP) and nuclear form factor (NF) and correlated with histologic grading of OSCC. Nuclear shape, membrane outline, chromatin clumps, nucleoli, and abnormal mitoses were also evaluated.

Results:

NA and NP were observed to be significantly increased in OSCC (P < 0.001) when compared with the control group. These values increased in correlation with increasing grades of OSCC. However, NF was found to more in the control group (P < 0.001).

Conclusion:

It may be concluded from the results that computer-assisted nuclear morphometry is a reliable tool for grading OSCC. A new grading system based on nuclear features for OSCC has been proposed.

Feulgen hydrolysis profiles and acid-labile DNA in oral squamous cell carcinoma

The full Feulgen hydrolysis profiles of healthy and malignant oral epithelial cells were compared by measuring the staining density of nuclei using microdensitometry after varying hydrolysis times. Malignant nuclei contained significantly increased levels of acid-labile DNA. The relative amounts of the rapidly hydrolysable fraction were compared after 5 min hydrolysis for exfoliating epithelial cells from healthy oral mucosa, healing chronic ulcers and squamous cell carcinomas. Although the latter exhibited a wide range of values, analysis of variance showed significant differences (P < 0.05) between healthy control and ulcer groups compared to oral carcinoma. The relative proportion of highly acid-labile DNA in malignant nuclei showed a significant positive correlation with mitotic score (P < 0.01) but no significant correlation with nuclear area. It was concluded that since the susceptibility of DNA to acid hydrolysis probably reflects functional differences in nuclear activity between cells, estimation of the highly acid-labile fraction may have diagnostic and/or prognostic value.

Tissue markers of potentially malignant human oral epithelial lesions

Tissue markers of potential malignancy have been sought for many years. Cell surface markers, particularly blood group and histocompatibility antigens, have shown great promise and several squamous carcinoma antigens have been identified--but not fully studied in potentially malignant lesions. Growth factors and receptors also need further study. Cytoplasmic markers of potential malignancy have been examined and, of these, keratins, filaggrin, and some carcinoma antigens show most promise. Nuclear analyses have promise but are time-consuming and expensive. Image cytometric analyses appear to be sensitive and predictive: oncogene and tumour suppressor analyses remain to be fully evaluated. New investigative techniques at the cellular and molecular level show increasing promise at defining potentially malignant oral epithelial lesions but more prospective studies are required.

Diagnostic significance of nuclear DNA content and nuclear area in oral hyperplasia, dysplasia, and carcinoma

The nuclear DNA content and the nuclear area in hyperplasia, dysplasia, and carcinoma of the oral cavity were quantitatively analyzed by microspectrophotometry. In carcinoma, marked variability of the nuclear DNA content and the nuclear area was found. The mean nuclear DNA content, the variance of the nuclear DNA content, the frequency of cells above tetraploid (4 C), the mean nuclear area, and the variance of nuclear area in hyperplasia and dysplasia were significantly different from these values with carcinoma. In some cases of leukoplakia and verrucous hyperplasia with subsequent malignant formation, the values were beyond the lower limit of carcinoma. The results suggest that the nuclear DNA and the nuclear area are important objective indices for predicting malignant potential of precancerous lesions.

DNA measurements in chronic hepatitis, cirrhosis and hepatocellular carcinoma

It has been documented that chronic hepatitis may progress to cirrhosis and then develop hepatocellular carcinoma (HCC). To test whether abnormal cellular DNA increases along this line of development, liver tissues from 48 patients with chronic hepatitis, 17 with cirrhosis, and 8 with HCC were investigated for cellular DNA content with a scanning microdensitometer. Seven of 8 HCCs and 2 cirrhotic livers adjacent to HCC had abnormally increased cellular DNA content. Only 4 livers from patients with chronic liver diseases other than HCC had abnormal cellular DNA content. The cellular DNA content in livers not accompanying HCC was not related to the patient's age, histological diagnosis, and hepatitis inflammatory activity. The results confirmed the increase of cellular DNA content in HCC, but did not provide evidence of a progressively increasing DNA content from chronic hepatitis to liver cirrhosis. However, cirrhotic livers with abnormal hepatocytic DNA content deserve careful follow-up for the early detection of HCC.

Which oral white lesions will become malignant? An image cytometric study

We investigated the value of image cytometry in predicting the prognosis of oral epithelial lesions, whether or not they show dysplasia. Thirty-five oral epithelial lesions were studied retrospectively. Of these, 23 had later transformed to carcinoma and 12 had not. By means of the Leitz TAS image analyzer, 200 nuclei of epithelial cells and 20 nuclei of lymphocytes from each section were individually assessed for eight features related to shape and amount of stain and for six features related to chromatin pattern. The mean, standard deviation, and interquartile range of each feature were calculated, first for each section and then for each group. With the use of linear stepwise discriminant analysis we constructed a predictive model, which consisted of three variables related to chromatin pattern. The variables were mean margination, standard deviation of clumping, and standard deviation of condensation. In the jackknife classification, this model predicted the malignant potential of the lesions that later transformed to cancer with 86% predictive value and 83% sensitivity.

Quantitative cytophotometric analysis as an aid to the detection of recurrent oral cancer

Quantitative cytophotometric analysis may be a useful adjunct to the detection of recurrence of malignancy, prior to it becoming visible, clinically. A case is reported by which DNA cytophotometry indicated recurrence on two occasions prior to its clinical diagnosis.

Prediction of malignant transformation in oral epithelial lesions by image cytometry

The value of image analysis in predicting the malignant potential of oral epithelial lesions showing either hyperplasia or dysplasia was investigated; 5-micron formalin-fixed sections of 16 oral epithelial lesions, of which eight had later transformed to carcinoma and eight had not transformed during a follow-up of 10-15 years were studied. The sections were stained with the azure A-Feulgen reaction for nuclear DNA. In each section 200 nuclei of epithelial cells and 20 nuclei of lymphocytes were assessed; all measurements were made blindly. For each nucleus six features related to shape and amount of stain and six features related to chromatin pattern were assessed. For each feature the mean, SD, and interquartile range were determined and used for linear stepwise discriminant analysis. A model of three variables with the most discriminating power was developed. When the jackknifed classification test was applied using this model, the malignant potential of the lesions that later transformed could be predicted with 87.5% accuracy.

Nuclear DNA analysis of oral hyperplasia and dysplasia using image cytometry

We investigated the value of image analysis in discriminating among oral white lesions with hyperplasia without dysplasia and oral white or white-and-red lesions with moderate or severe dysplasia. Normal oral epithelial tissue was used as a control. Image analysis was applied to 5-micron formalin-fixed sections stained with the azure A-Feulgen reaction for nuclear DNA. For 150-200 cells from each section, 5 nuclear variables were assessed: area, form factor, total stain, average stain and ellipticity. For each variable, 2 measurements were obtained, the mean and the interquartile range, and were used for stepwise discriminant analysis. Using this test, a model of 3 measurements with the most discriminating power was developed. When the jackknife classification test was applied to this model, we could discriminate with 81% accuracy between the 4 groups of tissue studied.

DNA-ploidy studies in a keratocyst undergoing subsequent malignant transformation

Using techniques that allow flow cytometry to be performed on tissue stored in paraffin wax, we have examined the DNA content of cells from an odontogenic keratocyst which underwent malignant transformation. On histological examination, the primary lesion was an odontogenic keratocyst showing dysplastic changes within the squamous epithelium. Flow cytometry revealed a prominent, abnormal DNA stemline, which was also present in the subsequent squamous cell carcinoma.

Quantitative exfoliative cytology of normal oral squames: an age, site and sex-related survey

This study describes the development of quantitative cytological techniques and their application to oral smears. Nuclear and cell size has been measured and matched with age, sex and site in an attempt to produce a baseline for comparison with identical measurements carried out on pathological smears. The results displayed a significant variation in nuclear and cytoplasmic area between different sites. Nuclear size varied significantly with advancing age; however, this was not the case for cytoplasmic area. There was no significant variation in either criterion between males and females.

Quantitative exfoliative cytology of normal and abnormal oral mucosal squames: preliminary communication

Quantitative techniques have been applied to the exfoliative cytology of normal and abnormal human oral mucosal squames. This study is ongoing but early results indicate that a normal baseline for clinically normal oral squames, related to age and site, may be difficult to achieve. However, results obtained for the pathological smears suggest that these techniques may improve the diagnostic sensitivity of cytology in the management of oral cancer.

Karyotypic abnormalities of squamous cell carcinoma of the oral cavity

The karyotypic abnormalities in 18 squamous cell carcinomas of the oral cavity were studied in unbanded chromosomes on direct preparations of the tumor material. The chromosome counts revealed a great variability in the number of chromosomes per cell of each tumor, the range being from 31 to 148 in all cases studied. The modal population of cells was diploid in five cases, triploid in eight cases, tetraploid and pentaploid in one case each. Reduction of the number of chromosomes was more consistently observed in groups A and B, frequently involving chromosome No 1 and increases in groups C, D, E, F and G. Markers were frequently present, the most common being an almost metacentric chromosome of the size of the chromosomes of Group C.

Epithelial cells kinetics. A review of methods of study and their application to oral mucosa in health and disease. Part B. Comparison of cell kinetics in normal and abnormal epithelia

In Part A, the techniques most commonly used to study epithelial cell kinetics and their suitability for use in man are reviewed. In Part B, the application of such methods to comparative studies of normal and abnormal oral epithelial of both man and experimental animals is examined. Claims regarding the possible prognostic value of LI's or MI's of biopsies of potentially or overtly malignant human oral lesions are also considered. Normal and abnormal kinetic data for other lining epithelia, e.g., skin, uterine cervix and gastrointestinal mucosa are assessed where they provide a better illustration of some of the problems arising in such comparative investigations. Finally, the present and likely future areas in which cell kinetic studies may provide a guide to expected tumour prognosis and optimum treatment are summarized.

Nuclear area and Feulgen DNA content of normal buccal mucosal smears

Malignant cells usually have an abnormal DNA content demonstrable by cytophotometry of Feulgen stained tissue. The diagnostic reliability of the technique is reduced because some malignant cells have a normal Feulgen DNA content. If Feulgen DNA content can be combined with measurements of additional cytological characteristics known to vary in malignancy, reliable diagnostic criteria may be forthcoming. In this study, Feulgen DNA content and nuclear area were estimated in 50 squames from the buccal mucosa in each of 14 young adults. Nuclear Feulgen DNA content was determined using an M85 microdensitometer and nuclear area was measured using a Reichert MOP image analyser. In each specimen, Feulgen DNA content was consistent with a nonreplicating cell population. Although nuclear area varied in each specimen, the variation in mean nuclear area among the sample of 14 was not statistically significant. It is concluded that nuclear area provides an accurate baseline against which future measurements on abnormal tissue can be compared.