Standardized AgNOR analysis of the invasive tumour front in oral squamous cell carcinomas

A Comparative Study of Morphometric Analysis of Nucleolar Organizer Regions in Oral Leukoplakia and Oral Squamous Cell Carcinoma and Significance of AgNOR as a Diagnostic Tool

Background Silver stainable nucleolar organizer regions (AgNORs) have proven to exhibit utmost importance due to their higher occurrence in the nucleus especially in malignant cells than in normal. Thus, they assist in the examination of nucleolar structures and variations in nucleolar activity. Aim Quantitative and qualitative analysis in relation to the number and area of AgNOR in tissue sections of the normal oral mucosa (NOM), oral leukoplakia (OL), and oral squamous cell carcinoma (OSCC) was the main aim of the study. Materials & method A total of 50 cases comprising 20 OL with dysplasia, 20 OSCC cases, and 10 samples of normal oral mucosa were taken. Silver nitrate (Sol A) & gelatin (Sol B) solutions were freshly prepared for staining the lesional slides. Results The mean value of nuclear profile area (A Nuc) was comparatively higher in oral leukoplakia i.e. 41.97 and in oral squamous cell carcinoma i.e. 62.36 in comparison to the control group where it was 36.19. The mean value of a single AgNOR profile area per nucleus (A NOR) was found to be comparatively lower in both study groups i.e. oral leukoplakia (2.76) and oral squamous cell carcinoma (1.61) in comparison to the control group (3.45) . The mean value of total AgNOR profile area per nucleus (TA NOR) and the number of profiles of AgNORs per nucleus (n NOR) were found higher in both study groups (oral leukoplakia and oral squamous cell carcinoma) as compared to normal oral mucosa of the control group. However, the findings of all four parameters of morphometric analysis were found to be significantly associated with disorder of oral mucosa i.e. cases of oral leukoplakia and oral squamous cell carcinoma (P value <0.01). Conclusion It can thus be suggested that the mean AgNOR count displayed a higher value in OSCC. Hence, the number of AgNORs in nuclei increases as epithelial cells undergo malignant transformation which is designated that mean AgNOR count may contribute to establishing the prognosis of a lesion.

Analysis of images for detection of oral epithelial dysplasia: A review

This paper provides a review of various image analysis approaches that have been previously used for recognition of dysplasia in images of the epithelium of the oral cavity. This domain has become especially admissible with the uncovering of the importance of image analysis which can probably be an aid to subjective diagnosis by histopathologists. Oral malignancy is a rampant form of cancer found among people of the Indian subcontinent due to various deleterious habits like consumption of tobacco, areca nut, betel leaf etc. Oral Submucous Fibrosis, a precancer, whose pathological category falls between normal epithelium and epithelial dysplasia, is caused because of these habits and can ultimately lead to oral cancer. Hence early detection of this condition is necessary. Image analysis methods for this purpose have an enormous potential which can also reduce the heavy workload of pathologists and to refine the criterion of interpretation. This paper starts with a critique of statistics of oral carcinoma in India and distribution of cancer in intra-oral sites and moves on to its causes and diagnostic approaches including causative agents, problems in curative approach and importance of image analysis in cancer detection. The various image analysis methods to appraise the cytological and architectural changes accompanied by Oral Epithelial Dysplasia in the images of the oral epithelial region have been described in relation to 2005 WHO Classification System and it was found that in future, analysis of images based on the mentioned methods has the potential in better interpretation and diagnosis of oral carcinoma.

Molecular changes in invasive front of oral cancer

Treatment planning for oral squamous cell carcinoma (OSCC) is based on the clinical TNM (Tumor, Node and Metastasis) classification. This system operates on the assumption that small tumours without clinical spread have a better prognosis than larger tumours with metastases. However, it is a well-known fact that some tumours with the same clinical staging show different growth patterns and clinical behaviour. This makes the prognosis for patients with OSCC difficult to predict on the basis of clinical staging alone. Although many histopathological characteristics of OSCC have been identified as prognostic factors, none is believed to be completely infallible. Therefore, a great need exists for more reliable prognostic markers, which will assist in treatment decisions. It is now well documented that several molecular events of significance for tumour spread, such as gain and loss of adhesion molecules, secretion of proteolytic enzymes, increased cell proliferation and initiation of angiogenesis occur at the tumour–host interface or invasive front, where the deepest and presumably most aggressive cells reside. This review describes the various molecular events and interactions, which take place in the invasive front of the OSCC, and elucidates their role as prognostic markers.

Association between Argyrophilic Proteins of Nucleolar Organizer Regions, Clinicomorphological Parameters, and Survival in Non-Small-Cell Lung Cancer

We studied argyrophilic proteins associated with nucleolar organizer regions (AgNOR) in non-small-cell cancer. We determined the area index (AI) and coefficient of variation (CV) of AgNOR. AI is associated with the key clinicomorphological parameters within the TNM system: T and N values, greatest tumor dimension up to 3 cm and more, disease stage, histogenesis, and tumor differentiation. CV is associated with T value, greatest tumor dimension up to 3 cm and more, histogenesis, and tumor differentiation. Survival of patients is longer in low AI or CV values versus high AI or CV values, longer in low AI and CV values (−AI/−CV type), shorter in high AI and CV values (+AI/+CV type), and intermediate in opposite AI and CV values (−AI/+CV and +AI/−CV types). Independent predictors in non-small-cell lung cancer include N value, greatest tumor dimension, histogenesis, and CV. Assessment of quantitative values and heterogeneity of AgNOR is important for differential diagnosis and prognosis of non-small-cell lung cancer.

Relationship between the argyrophilic proteins of the nucleolar organizer region and stage of squamous-cell carcinoma of the lung

Argyrophilic proteins associated with chromosome nucleolar organizer regions (Ag-NOR proteins) were studied in lung squamous-cell carcinoma cells. After routine staining with silver nitrate, the area index and coefficient of variations of Ag-NOR protein were estimated by computer-aided image analysis. The Ag-NOR protein area indexes of tumor cells differed in clinical morphological variants of squamous-cell cancer (differing by T and N parameters, size of the primary node <3 cm or larger, by disease stage, and differentiation degree). Ag-NOR protein variation coefficient can be used for discriminating the tumors by size (<3 cm and larger), presence/absence of metastases, and evaluation of squamous-cell cancer differentiation degree. Ag-NOR protein area index and variation coefficient can be used as additional objective differential diagnostic criteria of clinical and morphological forms of squamous-cell carcinoma of the lung.

Early detection of oral cancer: PAP and AgNOR staining in brush biopsies

Aim:

The aim of this study was to determine the diagnostic accuracy of routine Papanicolaou stain (PAP) and Silver stained Nucleolar Organizer Regions (AgNOR) staining in brush biopsies taken from suspected oral lesions for early detection of oral cancer.

Materials and Methods:

Brush biopsies were collected from macroscopically suspicious lesions of the oral cavity of 34 patients and 10 normal-aged and sex-matched controls. The numbers of AgNORs were counted in 100 squamous epithelial cell nuclei per slide after silver staining of the smears (Ploton’s one-step method).

Results:

Sensitivity and specificity of PAP analysis in the oral smears for detection of oral cancer and normal cells was 91.176% and 100%. The positive and negative prediction values were 100% and 76.92%, respectively. Sensitivity and specificity of AgNOR analysis in the oral smears for detection of oral cancer and normal cells was 100%. The positive and negative prediction values were 100% each.

Conclusion:

Based on the above facts, we conclude that brush biopsy in conjunction with AgNOR staining is an easily practicable, non-invasive, safe and accurate screening method for the detection of macroscopically suspicious oral cancerous lesions. Because of its simple technique and high reliability for cellular proliferation, AgNOR staining in brush smears can be used as an adjunct to other routine cytological diagnoses for the early detection of oral cancer. However, further investigations with more number of study samples will be needed to establish this correlation beyond doubt.

Histologic grading and nucleolar organizer regions in oral squamous cell carcinomas

Objective

The purposes of this study were to histologically assess different types of oral squamous cell carcinoma and the silver-binding nucleolar organizer region (AgNOR) morphology in neoplastic cells, as well as to quantify the number of AgNORs in each type of carcinoma in order to relate AgNOR count and histologic grading.

Material and Methods

Twenty-eight cases of oral squamous cell carcinoma were divided into 4 groups, namely well-differentiated, moderately differentiated, poorly differentiated, and undifferentiated. For NOR study, 3-µm-thick sections were stained with 50% aqueous silver nitrate solution. The predominant microscopic pattern of NORs was determined. Quantitative analyses of NORs were obtained of all cells present on each histological field using a 0.025 mm² eyepiece graticule. Different histological fields were analyzed until the total number of NORs was 120 cells for each tumor. Kruskall-Wallis test was applied to compare the groups of sample data at a significance level of p=0.05.

Results

The mean number of AgNORs per nucleus was 3.20 for the well-differentiated group, 5.33 for the moderately differentiated one, 8.27 for the poorly differentiated one, and 10.08 for the undifferentiated one. AgNOR count was significantly different (p<0.05) among all of the studied groups.

Conclusion

AgNOR staining technique seems to be a useful diagnostic tool since differences in AgNOR numeric values can be identified in the different types of oral squamous cell carcinoma. This technique is easy to handle and inexpensive, thus justifying its large use in histopathology.

Co-overexpression of p21 and Ki-67 in head and neck squamous cell carcinoma relative to a significantly poor prognosis

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) are treated by surgery or radiotherapy. Tumor cell death-related markers, such as p21 and Ki-67, may predict response to therapy and improve treatment choice. We evaluated and compared the effect of their coexpression between patients treated by surgery or radiotherapy.

METHODS

Immunohistochemistry for p21 and Ki-67 expression in 144 pharyngeal and laryngeal HNSCC samples was analyzed and correlated with follow-up parameters.

RESULTS

p21 expression correlated significantly with positive cN classification (p < .001), locoregional relapse (p = .031), and poor overall survival (p = .016), and Ki-67 positivity with poor survival only (p = .025). Coexpressing tumor phenotypes showed the worst survival (p = .009), observed primarily in patients treated by radiotherapy (p = .077).

CONCLUSIONS

Coexpression of p21/Ki-67 is a strong negative prognostic factor in HNSCC and could be of particular relevance in tumors treated by primary radiotherapy.

Actual proliferating index in oral squamous cell carcinoma and leukoplakia

AIM

  To examine the possible association between epithelial proliferation and disease progression in the oral mucosa using the actual proliferation index.

METHODS

  The actual proliferation index was measured by the Ki-67 labeling index and argyrophilic nucleolar organizer region count per nucleus. Immunohistochemistry was carried out for Ki-67 by using the molecular immunology borstel-1 clone in 20 leukoplakias, 20 oral squamous cell carcinomas, and 10 normal oral mucosae.

RESULTS

  The argyrophilic nucleolar organizer region count per nucleus, Ki-67 labeling index, and actual proliferation index were significantly higher in oral squamous cell carcinoma, followed by leukoplakia and normal oral mucosa. Leukoplakia with dysplasia showed a significantly higher Ki-67 labeling index and actual proliferation index, compared to leukoplakia without dysphasia. There was a significant correlation of Bryne's histological malignancy grading with the argyrophilic nucleolar organizer region count and the Ki-67 labeling index. There was a significant positive correlation between the argyrophilic nucleolar organizer region count and the Ki-67 labeling index among all groups.

CONCLUSIONS

  Leukoplakia or suspected epithelial dysplasia should be stained for argyrophilic nucleolar organizer regions and Ki-67. The actual proliferation index is not only useful as a prognostic factor, but could also be a promising treatment determining modality for patients with premalignant and malignant lesions.

Computer-assisted analysis of cell proliferation markers in oral lesions

Abnormalities in any component of the cell cycle regulatory machine may result in oral cancer, and markers of cell proliferation have been used to determine the prognosis of tumor progression. The aim of this study was to determine whether silver-stained nucleolar organizer region (AgNOR) and Ki-67 measurements could improve the assessment of growth rates in oral lesions. Eighty-three oral biopsies were studied, 20 of which were classified as fibrous inflammatory hyperplasia (FIH), 40 as leukoplakia (LKP) and 23 as oral squamous cell carcinoma (OSCC). Within the LKP group, 22 out of 29 biopsies were diagnosed as non-dysplastic leukoplakia (LK) and 18 as dysplastic leukoplakia (DLK), presenting discrete, moderate and severe dysplasia. Ki-67 immunolabeling of the lesions increased steadily in the following order: FIH, DLK, LK and OSCC, indicating that Ki-67 is a good marker for predicting the proliferative fraction among benign, premalignant and malignant oral lesions. The median values of AgNOR parameters indicate that the morphometric index gives better results regarding the proliferative rate than the numerical one. A series of linear regressions between AgNOR parameters and Ki-67 showed positive associations. We conclude that a combination of Ki-67 and morphometric AgNOR analyses could be used as an aid in the determination of the proliferative status of oral epithelial cells in oral cancer.

Molecular markers for diagnosis and prognosis

A plethora of aberrations are associated with progress and outcome for head and neck cancer patients and some have been shown to provide prognostic information independent of the TNM staging system. These findings justify future studies that will harness recent advances in technologies to refine the range of molecular markers available. Important lessons have been learnt during the last two decades, particularly the need to perform multivariate analysis and to combine information derived from several molecular markers. At present the overall evidence is insufficient to alter clinical practice or to consider restricting clinical trials of new adjuvant to subsets of patients, identified on the basis of the use of molecular markers. However, a number of key prospective clinical studies are in progress and we can be optimistic that in the near future clinical research incorporating specific markers may provide new criteria for defining risk of relapse or of developing a new primary tumour, and guide the choice of optimal adjuvant treatment after surgery. The only way to truly validate a marker is to incorporate it into large clinical trials, and it is anticipated that the new treatment options that are on the horizon, that are likely to be an improvement on radiotherapy alone, will provide opportunities to help translate this laboratory research into clinical practice.

Prognostic relevance of cell proliferation in head and neck tumors

Cell proliferative activity has been extensively investigated in head and neck tumors. Ki67/MIB-1 immunostaining, tritiated thymidine or bromodeoxyuridine labeling indices, DNA S-phase fraction, proliferating cell nuclear antigen expression, potential doubling time and analysis of the nucleolar organizer region associated proteins (AgNORs) have shown significant correlation with prognosis in 4806 cases of tumors of the oral cavity, salivary glands, pharynx and larynx. However, this was not observed in 2968 other reported cases. Discrepancies may depend on various factors: the heterogeneity of the series, which include tumors from various anatomic sites and patients treated with different therapy, and the lack of standardization of methods for assessing cell proliferation. Furthermore, none of the methods currently applied can by themselves define the actual proliferative activity, as it depends both on the proportion of cells committed to the cycle (growth fraction) and the speed of the cell cycle. Indeed, the actual proliferative activity of a tumor could well be measured by the equation [PA = Ki67 or MIB-1 scores x AgNORs], as we did in pharyngeal carcinoma. Provided that large and homogeneous series are evaluated by standardized methods, cell proliferative activity can still be regarded as an inexpensive and reliable prognostic factor in head and neck tumors.

The pathology of oral cancer

Oral cancer is a serious public health problem, with over 200,000 new cases reported annually worldwide, two-thirds of which occur in developing countries. The overall mortality rate for intra-oral cancer remains high at approximately 50%, even with modern medical services, probably due to the advanced stage of the disease at presentation. This review outlines recent advances in our understanding of the roles and interactions of major risk factors for oral cancer worldwide, notably tobacco, alcohol and betel quid and the genetic polymorphisms determining their metabolism that may predispose patients to oral carcinoma. Oral epithelial lesions with malignant potential are described. We discuss the histopathology of oral cancer, its grading and the staging of the disease at clinical, microscopic, immunohistological and molecular levels. A recommended minimum dataset for pathology reports is described. The available strategies and current prospects for controlling oral cancer in the community are summarised.

Diagnostic significance of FDG-PET and argyrophilic nucleolar organizer regions (AgNORs) in oral squamous cell carcinoma

Neoadjuvant chemoradiotherapy has played an important role in preserving organs and functions in patients with oral squamous cell carcinoma (SCC). To determine whether further operation after chemoradiotherapy is necessary, accurate evaluation of residual tumour cells after treatment is essential. We investigated the usefulness of regional fluorodeoxyglucose (FDG) uptake in combination with histochemical expression of AgNORs obtained from pretreatment biopsy specimens to assess residual tumours after intraarterial chemoradiotherapy. Standardized uptake value (SUV: pretreatment, pre-SUV; post-treatment, post-SUV) was calculated to determine the changes of FDG uptake in the tumour before and after chemoradiotherapy. Four out of 20 patients with oral SCCs showed residual tumour cells after treatment. Tumours with higher post-SUVs (> or =4.0) and higher AgNORs scores (> or =5.0) had significantly higher incidences of residual viable tumour cells after chemoradiotherapy (P=0.001). The results suggest that the combination of FDG-PET with AgNORs score is an excellent index for determining the optimal management of each patient following neoadjuvant chemoradiotherapy.

Invasive front in oral squamous cell carcinoma: image and flow cytometric analysis with clinicopathologic correlation

OBJECTIVE

Pathologists have drawn attention to the invasive tumor front (ITF) in the determination of the biologic aggressiveness of oral cancer. We have attempted to discover the prognostic significance of cancer cells with abnormal DNA content at the ITF of oral squamous cell carcinoma.

STUDY DESIGN

A comparative DNA analysis by means of image cytometry and flow cytometry was conducted to confirm the usefulness of image cytometry in detecting cancer cells having abnormal DNA content at the ITF. The prognostic value of cancer cells with abnormal DNA content ws examined by a multivariate analysis for 195 patients with oral squamous cell carcinoma.

RESULTS

In the comparative DNA analysis, it was suggested that image cytometry is useful for detecting cancer cells with abnormal DNA content (4c exceeding rate [4cER]), which is associated with poor prognosis of patients with oral squamous cell carcinoma. In the multivariate analysis, 3 independent factors were found to significantly influence cause-specific survival. These are, in decreasing order of influence, (1) abnormal DNA content (4cER), (2) clinical stage, and (3) growth type.

CONCLUSION

The presence of cancer cells with abnormal DNA content of the ITF in conjunction with clinical findings (clinical stage and growth type) can give additional useful information when selecting treatment strategies for oral cancer patients.

Prognostic value of graph theory-based tissue architecture analysis in carcinomas of the tongue

Several studies on oral squamous cell carcinomas (OSCC) suggest that the clinical value of traditional histologic grading is limited both by poor reproducibility and by low prognostic impact. However, the prognostic potential of a strictly quantitative and highly reproducible assessment of the tissue architecture in OSCC has not been evaluated. Using image analysis, in 193 cases of T1-2 (Stage I-II) OSCC we retrospectively investigated the prognostic impact of two graph theory-derived structural features: the average Delaunay Edge Length (DEL_av) and the average homogeneity of the Ulam Tree (ELH_av). Both structural features were derived from subgraphs of the Voronoi Diagram. The geometric centers of the cell nuclei were computed, generating a two-dimensional swarm of point-like seeds from which graphs could be constructed. The impact on survival of the computed values of ELH_av and DEL_av was estimated by the method of Kaplan and Meier, with relapse-free survival and overall survival as end-points. The prognostic values of DEL_av and ELH_av as computed for the invasive front, the superficial part of the carcinoma, the total carcinoma, and the normal-appearing oral mucosa were compared. For DEL_av, significant prognostic information was found in the invasive front (p < 0.001). No significant prognostic information was found in superficial part of the carcinoma (p = 0.34), in the carcinoma as a whole (p = 0.35), or in the normal-appearing mucosa (p = 0.27). For ELH_av, significant prognostic information was found in the invasive front (p = 0.01) and, surprisingly, in putatively normal mucosa (p = 0.03). No significant prognostic information was found in superficial parts of the carcinoma (p = 0.34) or in the total carcinoma (p = 0.11). In conclusion, strictly quantitative assessment of tissue architecture in the invasive front of OSCC yields highly prognostic information.

In situ standardised AgNOR analysis: a simplified method for routine use to determine prognosis and chemotherapy efficiency in colorectal adenocarcinoma

Standardised AgNOR analysis as recommended by the Committee on AgNOR Quantitation of the European Society of Pathology is now regarded as the gold standard, particularly when retrospective studies on archival, formalin-fixed, and paraffin-embedded material are performed. This article deals with the implementation of the standardised AgNOR method in colorectal carcinoma and its consequent impact on clinical decision making. First, the clinical relevance of AgNOR analysis as a major and independent prognostic factor in exclusively surgically treated adenocarcinomas of the colon and rectum is elucidated. Additionally, due to the fact that in last 10 years 5-Fluorouracil based chemotherapy and radiotherapy have become standard treatment in a variety of tumour stages, the outstanding predictive power of AgNOR analysis with regard to chemotherapy efficiency is emphasised.

Standardized in situ AgNOR analysis in breast pathology: diagnostic and cell kinetic implications

The aim of the present study was to assess the diagnostic value of the recently standardized morphometric analysis of silver-stained nucleolar organizer region-associated proteins (AgNORs) [30] in a variety of 155 routinely processed benign and malignant breast lesions. 5 normal breast samples, 21 adenoses, 20 ductal hyperplasias, 10 atypical ductal hyperplasias, 20 in situ and 43 invasive ductal carcinomas, 10 in situ and 26 invasive lobular carcinomas were investigated. A statistically highly significant difference was found between normal/ordinary hyperplastic and neoplastic breast lesions with all 4 consensus AgNOR parameters (mean area, mean number, CV of area, CV of number) evaluated. AgNOR quantity was significantly related to histological grade of both in situ and invasive carcinomas. However, variable overlap was found between AgNOR values in different diagnostic groups. We conclude that standardized AgNOR analysis is a prerequisite for objective and reproductible AgNOR assessment in archival tissues. Despite its limited diagnostic utility for individual breast lesions, standardized AgNOR analysis bears a significant potential for characterizing cell kinetic and metabolical activity of breast lesions. This may give insight into the biological background of breast carcinogenesis, differentiation and tumor progression and may also underlie the independent prognostic value of AgNORs in breast cancer.

Immunophenotypic analysis of normal mucosa and squamous cell carcinoma of the oral cavity

Detection of tumor-associated alterations in peritumoral normal mucosa may give insight into the molecular pathogenesis of oral cancer. In the present study, 100 archival oral squamous cell carcinomaswith adjacent nontumorous mucosa were immunohistochemically investigated with antibodies against p53, Mdm2, Bcl-2, WAF1, MIB1, epidermal growth factor receptor (EGF-R), and various CD44 isoforms. Additionally a standardized argyrophilic nucleolar organizer region (AgNOR)-associated proteins analysis was performed. No correlation was found between p53, Mdm2, Bcl-2, and WAF1 immunophenotypes of the respective tumors and adjacent mucosa. The proliferation-associated markers MIB1 and AgNORs showed a statistically significant sequential increase from normal to dysplastic mucosa to invasive carcinoma. Investigation of various CD44 adhesion molecules revealed a highly variable expression pattern in overt carcinomas with a significantly decreased expression of CD44 v4 and v9 variants and unaltered strong expression of v5 and v6 isoforms compared with normal oral epithelium. We conclude that proliferation markers (MIB1 and AgNORs), as well as selected CD44 isoforms, represent useful markers for the assessment of precancerous lesions. They may be utilized for screening patients at high risk for the development of oral cancer.

Evaluation of argyrophilic nucleolar organizer regions in tongue squamous cell carcinomas

Using a silver staining technique, argyrophilic nucleolar organizer regions (AgNORs) were studied on the biopsy specimens taken from 67 tongue squamous cell carcinomas (SCCs), and the relations of the results of AgNORs to the clinicopathological findings, to the labelling indices of proliferating cell nuclear antigen (PCNA LI), and to the outcomes of the disease were investigated. The mean numbers of AgNORs per cell were 1.67 +/- 0.19 (n = 27) in the control squamous epithelia and 3.58 +/- 1.15 (n = 67) in the tongue SCCs, respectively, and a significant difference was found between the two groups (P < 0.0001). Concerning the clinicopathological findings, the mean numbers of AgNORs in the progressive cases (T3, T4), in the factor N-positive groups (N1, N2), and in the advanced stages (stages III, IV) were statistically higher than those in T1, T2, N0, and earlier stage (stages I, II) tumours, respectively. Similarly, a higher value of the AgNOR count was present in the histological grade III or diffuse invasive tumour. There was also a directly significant correlation between the AgNOR counts and the labelling indices of PCNA (r = 0.53, P < 0.0001). Concerning the outcome of the disease, the mean numbers of AgNORs were higher in the group with local recurrence or with lymph-node metastasis. A lower rate of 5 years' survival was found in the high value group (63.5%) of AgNORs compared with that of the low value group (86.0%), with a significant difference between the two groups (P < 0.05). The results suggest that AgNORs may reflect the degree of malignancy and cellular proliferation in tongue SCCs.

Is the invasive front of an oral carcinoma the most important area for prognostication?

The prognosis for patients with oral squamous cell carcinomas is difficult to predict. There is therefore a great need for more reliable prognostic markers which will be of help in the treatment decisions. In this review I present a hypothesis which suggests that molecular and morphological characteristics at the invasive front area of various carcinomas may reflect tumour prognosis better than other parts of the tumour. It is now known that several molecular events of importance for tumour spread like gains and losses of adhesion molecules, secretion of proteolytic enzymes, increased cell proliferation and initiation of angiogenesis occur at the tumour-host interface (invasive front). Consequently, our group has recently developed a simple morphological malignancy grading system that restricts the evaluation to the deep invasive front area of the tumour. Several studies have shown that this system is a significantly better predictor of prognosis than traditionally used morphological systems. All studies performed so far show that invasive front grading is a valuable supplement to clinical staging, suggesting that it should be introduced into the clinic.