Invasive pattern grading score designed as an independent prognostic indicator in oral squamous cell carcinoma

Establishment and validation of a tumor-infiltrating γδT cell related prognostic gene signature in head and neck squamous cell carcinoma

γδT cells are unconventional T cells only accounting for 1-5 % of circulating T lymphocytes. Their potent anti-tumor capability has been evidenced by accumulating studies. However, the prognostic value of γδT cells remains not well documented in head and neck squamous cell carcinoma (HNSCC). In this study, we utilized the TCGA HNSCC database to evaluate the infiltration of γδT cells and the association between γδT cells and clinicopathological factors by related gene signature, which were then validated by a total of 100 collected tumor samples from HNSCC patient cohort. Heterogeneity and functional characteristics of distinct infiltrating γδT cell profiles in HNSCC were then investigated based on the scRNA-seq data from the GEO database. We found higher γδT cell gene signature score was significantly associated with longer survival. Cox regression models showed that γδT cell gene signature could serve as an independent prognostic indicator for HNSCC patients. A high level of γδT cell-related gene signature was positively correlated with the infiltration of tumor-infiltrating lymphocytes and immune score. Through scRNA-seq analysis, we identified that γδ+ Trm cells and γδ+ CTL cells possessed anti-tumor and immunoregulatory properties. Notably, we found a significant association between the presence of these cells and improved survival outcomes. In our cell-cell communication analyses, we identified that γδT cells have the potential to eliminate tumor cells through the secretion of interferon-gamma and granzyme. Collectively, the infiltration of γδT cells may serve as a promising prognostic tool, prompting the consideration of treatment options for patients with HNSCC.

Pre-operative incisional biopsy of oral squamous cell carcinoma: high podoplanin expression is related to perineural invasion and may be a useful predictor of disease progression

OBJECTIVE

Immunohistochemical analysis of podoplanin expression as a pre-operative molecular marker for perineural invasion (PNI) may represent an attractive strategy for surgical management of oral squamous cell cancer (OSCC). We evaluated the relationship between podoplanin expression and PNI in pre-operative incisional biopsies of OSCC.

STUDY DESIGN

After performing pathological staging and histologic and immunohistochemical evaluation of 83 surgical specimens, we performed multivariable logistic regression analysis to examine the relationship between PNI and independent variables. To evaluate the utility of podoplanin immunopositivity for discrimination of PNI status pre-operatively, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value. We performed receiver operating characteristic curve analysis to evaluate the diagnostic accuracy of podoplanin immunopositivity for predicting PNI alone and in combination with age, T stage, N stage, and index site.

RESULTS

We observed podoplanin expression in 42 (50.6%) of all the 83 pre-operative incisional biopsies and 29 of the pre-operative biopsies of the 31 (93.5%) postoperative specimens with PNI. The rate of podoplanin expression was significantly higher in patients with pT3 to pT4 stage and pN+ stage disease. Podoplanin positivity in the pre-operative biopsy showed high sensitivity in predicting PNI in the surgical specimen.

CONCLUSION

Podoplanin expression appears to be an independent pre-operative variable significantly related to PNI and a possibly valuable prognostic marker for therapeutical planning and surgical treatment of OSCC.

WPOI-5: Accurately Identified at Intraoperative Consultation and Predictive of Occult Cervical Metastases

BACKGROUND

Frozen section analysis of oral cancer specimens is ideal for assessing margin distances and depth of invasion (DOI); the latter impacts intraoperative decisions regarding elective neck dissection (END). Here, we show that intraoperative determination of worst pattern of invasion (WPOI), specifically WPOI-5, has a high level of accuracy. This relates to our demonstration herein that WPOI-5 predicts occult cervical metastases (OCM) for pT1 oral squamous carcinoma (OSC).

METHODS

The presence of OCM was correlated with WPOI in 228 patients with primary T1/T2/cN0 OSC undergoing resection and END. Concordance between intraoperative and final pathology WPOI determination was assessed on 51 cases of OSC.

RESULTS

WPOI-5 predicts OCM in pT1 patients, compared with WPOI-4/WPOI-3 (p < 0.0001). Most pT1 WPOI-5 tumors had DOI of 4-5 mm (24/59 or 40.7%). Only two pT1 WPOI-5 tumors had DOI < 4 mm (3.0 and 3.5 mm). If END were performed in this pT1 cohort for all WPOI-5 OSC patients regardless of DOI, OR all OSC patients with DOI ≥ 4 mm regardless of WPOI, then no OCM would be missed (p = 0.017, 100% sensitivity, 29% specificity, 77% positive predictive value, 23% negative predictive value). With respect to intraoperative WPOI-5 determination, the accuracy, sensitivity, and specificity was 92.16, 73.33, and 100.0%, respectively.

CONCLUSIONS

DOI ≥ 4 mm is the dominant predictor of OCM. For the rare WPOI-5 OSC with DOI < 4 mm, it is reasonable to suggest that surgeons perform END. WPOI-5 may be accurately determined intraoperatively. As microscopic instruction is needed to accurately assess WPOI-5, a teaching link is included in this manuscript.

Significance of Pattern of Invasion in Tongue Squamous Cell Carcinoma—A Retrospective Study from a Regional Cancer Center of North-East India

Introduction Many multiparametric models and scoring systems had been proposed in oral tongue squamous cell carcinoma (OTSCC) to predict the survival and recurrence, out of which pattern of invasion (POI) is gaining focus recently.

Objective We conducted a retrospective study with the aim to see the prognostic significance of the POI and other parameters such as depth of invasion, perineural invasion (PNI), and lymph node status in OTSCC.

Materials and Methods The slides of already diagnosed OTSCC cases were prepared from January 2015 to December 2017 records and studied by two pathologists for different patterns using Brandwein-Gensler scoring system. The different clinicopathologic parameters were compared with different POI. Statistical analysis was performed to present cumulative survival outcomes and for comparison.

Results Most of our patients were > 40 years of age with male preponderance. Tumor differentiation pattern was assessed using Broders' system of grading that showed 85% of tumors were well, 12.5% tumors were moderately differentiated, and 2.5% tumors were poorly differentiated. The worst POI was predominantly pattern III (50%) followed by pattern II (32.5%) and pattern IV (13.8%). Most patients were in stage II (33.8%) followed by stage III (32.5%), stage IV (26.3%), and stage I (7.5%). There was an inverse relationship between POI with tumor stage and recurrence. A strong statistically significant association was found between POI with perineural infiltration and lymph node metastasis.

Conclusion We concluded from our study that worst POI is significantly associated with number of lymph nodes metastasis and perineural infiltration and hence can be used as an independent prognostic factor.

A 13-Gene DNA Methylation Analysis Using Oral Brushing Specimens as an Indicator of Oral Cancer Risk: A Descriptive Case Report

Analysis of genetic or epigenetic markers from saliva or brushing specimens has been proposed as a diagnostic aid to identify patients at risk of developing oral cancer. However, no reliable non-invasive molecular method for this purpose is commercially available. In the present report, we describe the potential application of a procedure based on a 13-gene DNA methylation analysis using oral brushing samples from a patient affected by oral leukoplakia who developed two metachronous oral carcinomas during the follow-up period. A positive or a negative score was calculated for each brushing sample based on a predefined cut-off value. In this patient, a positive score was detected in the oral leukoplakia diagnosed more than 2 years before the development of oral squamous cell carcinoma and subsequently in clinically healthy mucosa 8 months before the appearance of a secondary tumor. This suggests a potential role of our procedure as an indicator of oral cancer risk.

Clinicopathologic Characteristics of Young Patients with Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) occasionally occurs in young patients and is likely to be distinct from OSCC in older patients. In this retrospective study, we described the clinicopathologic features and outcome of 150 OSCCs that were diagnosed in patients 40-year-old or younger. Most patients (63%) were non-smokers. The most common site of the primary tumor was oral tongue (n = 131, 87%), followed by gingiva (n = 9), buccal mucosa (n = 8) and lip (n = 2). The median patients' age at presentation was 34 (range: 16-40). Seven patients (5%) had Fanconi anemia with the gingiva being the most common location (4/7, 57%). All OSCCs were of keratinizing type. All cases tested for high-risk HPV (n = 34) were negative. On univariate analysis, high tumor budding was associated with decreased overall survival (OS) and distant metastasis free survival (DMFS), pattern of invasion correlated with OS and tumors with high stromal tumor infiltrating lymphocytes (sTIL) were associated with improved locoregional recurrence free survival (LRFS). Compared with patients 31 to 40-year-old, OSCC in the younger group was associated with significant less alcohol consumption (p = 0.011) and decreased DSS (p = 0.003) and DMFS (p = 0.023). On multivariate analysis, younger age (30 years or younger) was an independent prognostic factor for worse OS and DSS, whereas histologic grade was an independent prognostic factor for DSS. In summary, most OSCC in young patients occurred in non-smokers and did not occur in association with Fanconi anemia. Independent prognostic factors included age at presentation (30 years or younger) for OS and DSS, and histologic grade for DSS.

Epithelial Distribution of E-Cadherin, p63, and Mitotic Figures in ApoTome Images to Determine the Oncogenic Potentiality of Oral Submucous Fibrosis

The exact process of the malignant conversion of oral submucous fibrosis (OSF) to oral cancer is not fully understood. This study aimed to detect and analyze E-cadherin expression, p63 expression, and number of mitotic figures, all correlated to cancer development, in ApoTome images of oral tissues to determine the oncogenic potentiality of OSF. ApoTome images of the study groups (6 normal, 16 OSF with dysplasia, and 10 OSF without dysplasia) were recorded. Cytoplasmic and membranous E-cadherin expression, breakages of the cell membrane, and p63 expression were detected in MATLAB 2016b. The number of mitotic figures detected by MATLAB was correlated with the number of chromosomes detected by ImageJ. A Mann–Whitney U test was done to determine a significant difference between the study groups for cytoplasmic and membranous E-cadherin distribution points. Statistical significant differences were found for cytoplasmic E-cadherin distribution between normal and OSF (with dysplasia) (p = 0.0278). There was an increase in mitotic figures, p63 expression, and cytoplasmic E-cadherin expression and a decrease in membranous E-cadherin expression from normal to diseased condition. Hence, automated detection and quantification of E-cadherin, p63, and mitotic figures in ApoTome images of oral biopsies can help in determining the oncogenic potentiality of OSF.

Pre-Operative Evaluation of DNA Methylation Profile in Oral Squamous Cell Carcinoma Can Predict Tumor Aggressive Potential

BACKGROUND

Prognosis of oral squamous cell carcinoma (OSCC) is difficult to exactly assess on pre-operative biopsies. Since OSCC DNA methylation profile has proved to be a useful pre-operative diagnostic tool, the aim of the present study was to evaluate the prognostic impact of DNA methylation profile to discriminate OSCC with high and low aggressive potential.

METHODS

36 OSCC cases underwent neoplastic cells collection by gentle brushing of the lesion, before performing a pre-operative biopsy. The CpG islands methylation status of 13 gene (ZAP70, ITGA4, KIF1A, PARP15, EPHX3, NTM, LRRTM1, FLI1, MiR193, LINC00599, MiR296, TERT, GP1BB) was studied by bisulfite Next Generation Sequencing (NGS). A Cox proportional hazards model via likelihood-based component-wise boosting was used to evaluate the prognostic power of the CpG sites.

RESULTS

The boosting estimation identified five CpGs with prognostic significance: EPHX3-24, EPHX3-26, ITGA4-3, ITGA4-4, and MiR193-3. The combination of significant CpGs provided promising results for adverse events prediction (Brier score = 0.080, C-index = 0.802 and AUC = 0.850). ITGA4 had a strong prognostic power in patients with early OSCC.

CONCLUSIONS

These data confirm that the study of methylation profile provides new insights into the molecular mechanisms of OSCC and can allow a better OSCC prognostic stratification even before surgery.

Tumor Budding and Worse Pattern of Invasion Can Predict Nodal Metastasis in Oral Cancers and Associated With Poor Survival in Early-Stage Tumors

The management and prognosis of oral squamous cell carcinoma (OSCC) depend on tumor stage and lymph node (LN) metastasis status. Early-stage (T1/T2 N0M0) OSCC comprises a heterogeneous group. We evaluated the role of histological parameters including worst pattern of invasion (WPOI) and tumor budding to determine the risk of LN metastasis in cases of OSCC and to determine the risk of recurrence and death in early-stage OSCC in north Indian patients. All cases of buccal mucosa and tongue SCC which underwent excision over 4 and half years were reviewed for histological parameters including histologic grade, WPOI, tumor budding, lymphovascular emboli (LVE), perineural invasion (PNI), depth of invasion (DOI), host lymphocyte response, and stromal response and compared to LN metastasis. Clinical follow-up of early-stage tumor was obtained and compared. A total of 126 cases of OSCC were included, of which 48 showed LN metastasis. Histological grade, WPOI, tumor budding (≥3/×40 field), LVE, and PNI were significantly associated with risk of LN metastasis. On multivariate analysis, WPOI and tumor budding were 2 most significant factors. Among the early-stage tumors with available follow up (n = 48), DOI, WPOI, tumor budding, and LVE were associated with a shorter overall survival, although it was not statistically significant. To conclude, WPOI and tumor budding are important risk factors for predicting LN metastasis in all stages of OSCC and associated with a poorer outcome in early-stage tumors. These are easy and reliable prognostic factors and should be included in the histopathological reporting guidelines.

Expression and role of regulator of G-protein signaling 5 in squamous cell carcinoma of the tongue

Regulator of G-protein signaling (RGS) 5 acts as a GTPase-activating protein to negatively regulate G-protein signaling. RGS5 is reportedly related to the invasion and metastasis of cancers, such as nonsmall lung cancer and hepatocellular carcinoma. We examined RGS5 expression and its relationship with invasion in squamous cell carcinoma (SCC) of the tongue. For immunohistochemical analysis of RGS5, we used SCC tissues of the tongue obtained from 43 patients. We examined the relationship between RGS5 expression in the deepest point of invasion and clinicopathological features. Because the invasion and metastasis of cancers are related to epithelial-mesenchymal transition (EMT), we carried out staining for N-cadherin, vimentin, and E-cadherin to examine the relationship between EMT and RGS5. RGS5 expression in the deepest point of invasion in SCC of the tongue was observed in 32 cases (75%). Immunohistochemical analysis revealed a significant correlation between RGS5 expression in the aggressive invasion pattern, invasion depth, and lymphovascular invasion. Kaplan-Meier analysis revealed that high RGS5 expression was associated with postoperative early lymph node metastasis. Further, a significant positive correlation was observed between RGS5 and N-cadherin (P = 0.0003) and vimentin (P < 0.0001). In contrast, E-cadherin and RGS5 or vimentin were significantly negatively correlated (P < 0.0001-0.005). The findings indicate that RGS5 expression is related to tumor invasion and EMT in SCC of the tongue and that RGS5 may predict postoperative early lymph node metastasis. Therefore, RGS5 may be a useful prognostic biomarker of the surgically resected SCC and a potential target of molecular therapy for treating SCC of the tongue.

Depth of invasion alone as an indication for postoperative radiotherapy in small oral squamous cell carcinomas: An International Collaborative Study

BACKGROUND

We aimed to investigate whether depth of invasion (DOI) should be an independent indication for postoperative radiotherapy (PORT) in small oral squamous cell carcinomas (SCC).

METHODS

Retrospective analysis of DOI (<5, 5 to <10, ≥10 mm) and disease-specific survival (DSS) in a multi-institutional international cohort of 1409 patients with oral SCC ≤4 cm in size treated between 1990-2011.

RESULTS

In patients without other adverse factors (nodal metastases; close [<5 mm] or involved margins), there was no association between DOI and DSS, with an excellent prognosis irrespective of depth. In the absence of PORT, the 5-year disease-specific mortality was 10% with DOI ≥10 mm, 8% with DOI 5-10 mm, and 6% with DOI <5 mm (P = .169), yielding an absolute risk difference of only 4%.

CONCLUSION

The deterioration in prognosis with increasing DOI largely reflects an association with other adverse features. In the absence of these, depth alone should not be an indication for PORT outside a clinical trial.

A novel prognostic model for tongue squamous cell carcinoma based on the characteristics of tumour and its microenvironment: iBD score

AIMS

Tumour budding and invasive depth can predict survival of patients with tongue squamous cell carcinoma (TSCC), while the prognostic value of tumour microenvironment (TME) remains unknown. Here, both characteristics of the tumour and its microenvironment were examined and a novel prognostic model has been proposed.

METHODS AND RESULTS

A total of 246 patients with TSCC were included. Using H&E-stained sections, pathological parameters of tumour and the TME were assessed. Inflammatory response (i), tumour budding (B) and invasive depth (D) were combined as iBD score. The association between these variables and the patient survival was determined. Both tumour budding and inflammatory status were independent variables for predicting overall survival (OS) and disease-free survival (DFS) of TSCC patients. Invasive depth was correlated with differentiation, T classification, lymph node metastasis, clinical stage and recurrence (P < 0.05). The novel iBD model was strongly correlated with T classification, lymph node metastasis, clinical stage and recurrence, and showed clear distinction of scores 0, 1 and 2. High iBD score had a strong association with reduced OS and DFS (P < 0.01).

CONCLUSIONS

The iBD scoring model is strongly associated with lymph node metastasis and recurrence in TSCC and could be a promising survival predictor for TSCC patients.

Novel prognostic histopathological grading system in oral squamous cell carcinoma based on tumour budding and cell nest size shows high interobserver and intraobserver concordance

AIMS

Squamous cell carcinoma of the oral cavity (OSCC) is a common tumour entity with a variable, partially highly aggressive clinical course. Recently, we proposed a novel (three-tiered) clinically useful grading scheme strongly associated with patient outcome in OSCC, consisting of a sum score of the histomorphological patterns tumour budding and cell nest size which outperforms WHO based grading algorithms currently in use. The aim of our study was to probe for interobserver and intraobserver reliability of this novel grading system.

METHODS

108 OSCC were retrospectively scored according to the proposed grading scheme by three independent pathologists-two experienced head and neck pathologists and one pathologist in training-blinded to each other's scoring results.

RESULTS

The Cohen's Kappa (κ) values for concordance rates between experienced pathologists were κ=0.97 for the overall grade, κ=0.97 for budding activity and κ=0.91 for cell nest size, indicating a strong interobserver reliability of our proposed grading system. Initial interobserver agreement was markedly lower with the pathologist in training (κ=0.55 for overall grade) but improved significantly after a training session (κ=0.87 for overall grade). Intraobserver concordance was high (κ=0.95 for overall grade), indicating a high reproducibility of the algorithm.

CONCLUSIONS

In conclusion, our study indicates that OSCC grading based on our proposed novel scheme yields an excellent inter-reader and intrareader agreement, further supporting the suitability of this grading system for routine pathological practice.

Increased chemoresistance via Snail-Raf kinase inhibitor protein signaling in colorectal cancer in response to a nicotine derivative

A tobacco-specific component, 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK), is a major risk factor for many cancers. Recent reports have demonstrated that NNK exposure may be associated with tumor progression and chemoresistance in certain cancers. However, the underlying NNK-induced mechanism contributing to the aggressiveness of colorectal cancer (CRC) has not been thoroughly studied. In this study, we used HT29 cells treated with NNK to simulate the long-term exposure of cigarette smoke. A comparative analysis was performed to evaluate cell proliferation, migration, and invasion as well as epithelial-mesenchymal transition (EMT) markers and drug-resistance genes expression, cancer stem cell (CSC) properties, and anti-apoptotic activity. Signaling pathways related to chemoresistance were also investigated. As a result, NNK exposure dose-dependently stimulates cell proliferation, enhance abilities of migration and invasion, induce EMT phenomenon, and attenuate apoptosis. Furthermore, NNK exposure also promotes the capabilities of sphere formation, upregulation of Snail, and overexpression of CD133, Nanog, OCT4, and the drug-resistant genes. Knockdown of Snail results in upregulation of Raf kinase inhibitor protein (RKIP), increased apoptosis, reversal of EMT phenomenon, and reducation of expression of CSC markers, all of which contribute to a decrease of chemoresistance. Our study demonstrates a number of related mechanisms that mediate the effect of NNK exposure on increasing CRC therapeutic resistance via the Snail signaling pathway. Targeting Snail may provide a feasible strategy for the treatment of CRC.

An oral cavity squamous cell carcinoma quantitative histomorphometric-based image classifier of nuclear morphology can risk stratify patients for disease-specific survival

Oral cavity squamous cell carcinoma is the most common type of head and neck carcinoma. Its incidence is increasing worldwide, and it is associated with major morbidity and mortality. It is often unclear which patients have aggressive, treatment refractory tumors vs those whose tumors will be more responsive to treatment. Better identification of patients with high- vs low-risk cancers could help provide more tailored treatment approaches and could improve survival rates while decreasing treatment-related morbidity. This study investigates computer-extracted image features of nuclear shape and texture on digitized images of H&E-stained tissue sections for risk stratification of oral cavity squamous cell carcinoma patients compared with standard clinical and pathologic parameters. With a tissue microarray cohort of 115 retrospectively identified oral cavity squamous cell carcinoma patients, 50 were randomly chosen as the modeling set, and the remaining 65 constituted the test set. Following nuclear segmentation and feature extraction, the Wilcoxon rank sum test was used to identify the five most prognostic quantitative histomorphometric features from the modeling set. These top ranked features were then combined via a machine learning classifier to construct the oral cavity histomorphometric-based image classifier (OHbIC). The classifier was then validated for its ability to risk stratify patients for disease-specific outcomes on the test set. On the test set, the classifier yielded an area under the receiver operating characteristic curve of 0.72 in distinguishing disease-specific outcomes. In univariate survival analysis, high-risk patients predicted by the classifier had significantly poorer disease-specific survival (P=0.0335). In multivariate analysis controlling for T/N-stage, resection margins, and smoking status, positive classifier results were independently predictive of poorer disease-specific survival: hazard ratio (95% confidence interval)=11.023 (2.62-46.38) and P=0.001. Our results suggest that quantitative histomorphometric features of local nuclear architecture derived from digitized H&E slides of oral cavity squamous cell carcinomas are independently predictive of patient survival.

A semi-quantitative World Health Organization grading scheme evaluating worst tumor differentiation predicts disease-free survival in oral squamous carcinoma patients

We investigated World Health Organization (WHO) grading and pattern of invasion based histological schemes as independent predictors of disease-free survival, in oral squamous carcinoma patients. Tumor resection slides of eighty-seven oral squamous carcinoma patients [pTNM: I&II/III&IV-32/55] were evaluated. Besides examining various patterns of invasion, invasive front grade, predominant and worst (highest) WHO grade were recorded. For worst WHO grading, poor-undifferentiated component was estimated semi-quantitatively at advancing tumor edge (invasive growth front) in histology sections. Tumor recurrence was observed in 31 (35.6%) cases. The 2-year disease-free survival was 47% [Median: 656; follow-up: 14-1450] days. Using receiver operating characteristic curves, we defined poor-undifferentiated component exceeding 5% of tumor as the cutoff to assign an oral squamous carcinoma as grade-3, when following worst WHO grading. Kaplan-Meier curves for disease-free survival revealed prognostic association with nodal involvement, tumor size, worst WHO grading; most common pattern of invasion and invasive pattern grading score (sum of two most predominant patterns of invasion). In further multivariate analysis, tumor size (>2.5cm) and worst WHO grading (grade-3 tumors) independently predicted reduced disease-free survival [HR, 2.85; P=0.028 and HR, 3.37; P=0.031 respectively]. The inter-observer agreement was moderate for observers who semi-quantitatively estimated percentage of poor-undifferentiated morphology in oral squamous carcinomas. Our results support the value of semi-quantitative method to assign tumors as grade-3 with worst WHO grading for predicting reduced disease-free survival. Despite limitations, of the various histological tumor stratification schemes, WHO grading holds adjunctive value for its prognostic role, ease and universal familiarity.

Analysis of the invasive edge in primary and secondary oral squamous cell carcinoma: An independent prognostic marker: A retrospective study

BACKGROUND AND OBJECTIVES

Oral squamous cell carcinoma (OSCC) is one of the most common head and neck carcinomas and corresponds to 95% of all oral cancers with an increasing morbidity and mortality. Its prognosis is affected by several clinicopathologic factors, one of which is pattern of invasion (POI). The histological features of OSCC may differ widely, but there is general agreement that the most useful prognostic information can be deduced from the invasive front of the tumor. In this retrospective study, our aim was to compare the POI, the status of connective tissue and the status of inflammation at the tumor-host interface in primary and recurrent (secondary) OSCC and test the validity of POI, to serve as a potential marker to assess the prognosis of the patient.

MATERIALS AND METHODS

Differentiation of tumors, POI, status of connective tissue and inflammation was assessed in 168 cases of primary and recurrent cases of OSCC.

STATISTICAL ANALYSIS

Fisher's exact test was used to determine the statistical significance and P < 0.05 was considered to be statistically significant.

RESULTS

Our study showed that majority of the primary and secondary tumors were well differentiated, 117 [95.9%] and 34 [73.9%], respectively. Predominant POI in the primary and secondary tumor group was Pattern II and least was Pattern V. Worst pattern in primary tumor and highest distribution was seen for Pattern III (53.3%), and least for Pattern V (0.00%). In secondary tumors, the predominant worst pattern was Pattern IV (50.0%) and least distribution was seen for Pattern I (0.00%). Connective tissue status for both primary and secondary tumors showed the predominance of loose type (85.2% and 79.2%) and least was variable type (0.8% and 0.6%), respectively. Status of inflammation in the primary tumor group showed a predominance of moderate grade of inflammation (50.0%) and very mild grade of inflammation (6.6%) was the least type. In the secondary tumor group, moderate grade (43.5%) of inflammation was predominant and very mild grade (5.4%) was the least. All the parameters showed a statistically significant difference on the application of Fisher's exact test between the two groups.

CONCLUSION

Our study showed that POI could serve as an individual prognostic marker irrespective of the histologic differentiation of tumor. Tumor desmoplasia could be considered as an important reflection of the tumor-host interaction, especially in aggressive cancers. Host immune defense, especially tumor infiltrating lymphocytes must be noted as critical factors related to survival rate in OSCC patients. Assessment of mentioned parameters may lead to sound prognostic assessment and appropriate treatment planning thus reducing the possibility of recurrence or relapse. Hence, the parameters evaluated in our study could serve as independent or interdependent prognostic markers.

Molecular Portrait of Oral Tongue Squamous Cell Carcinoma Shown by Integrative Meta-Analysis of Expression Profiles with Validations

Oral Tongue Squamous cell carcinoma (OTSCC), the most frequently affected oral cancer sub-site, is associated with a poor therapeutic outcome and survival despite aggressive multi- modality management. Till date, there are no established biomarkers to indicate prognosis and outcome in patients presenting with tongue cancer. There is an urgent need for reliable molecular prognostic factors to enable identification of patients with high risk of recurrence and treatment failure in OTSCC management. In the current study, we present the meta-analysis of OTSCC microarray based gene expression profiles, deriving a comprehensive molecular portrait of tongue cancer biology, showing the relevant genes and pathways which can be pursued further to derive novel, tailored therapeutics as well as for prognostication. We have studied 5 gene expression profiling data sets available on exclusively oral tongue subsite comprising of sample size; n = 190, consisting of 111 tumors and 79 normals. The meta- analysis results showed 2405 genes differentially regulated comparing OTSCC tumor and normal. The top up regulated genes were found to be involved in Extracellular matrix degradation (ECM) and Epithelial to mesenchymal transition (EMT) pathways. The top down regulated genes were found to be involved in detoxication pathways. We validated the results in clinical samples (n = 206), comprising of histologically normals (n = 10), prospective (n = 29) and retrospective (n = 167) OTSCC by evaluating MMP9 and E-cadherin gene expression by qPCR and immunohistochemistry. Consistent with meta-analysis results, MMP9 mRNA expression was significantly up regulated in OTSCC primary tumors compared to normals. MMP9 protein over expression was found to be a significant predictor of poor prognosis, disease recurrence and poor Disease Free Survival (DFS) in OTSCC patients. Analysis by univariate and multivariate Cox proportional hazard model showed patients with loss of E-cadherin expression in OTSCC tumors having a poorer DFS (HR = 1.566; P value = 0.045) and poorer Overall Survival (OS) (HR = 1.224; P value = 0.003) respectively. Combined over-expression of MMP9 and loss of E-cadherin membrane positivity in the invasive tumor front (ITF) of OTSCC had a significant association with poorer DFS (Log Rank = 16.040; P value = 0.001). These results suggest that along with known clinical indicators of prognosis like occult node positivity, assessment of MMP9 and E-cadherin expression at ITF can be useful to identify patients at high risk and requiring a more intensive treatment strategy for OTSCC. Meta-analysis study of gene expression profiles indicates that OTSCC is a disease of ECM degradation leading to activated EMT processes implying the aggressive nature of the disease. The triggers for these processes should be studied further. Newer clinical application with agents that can inhibit the mediators of ECM degradation may be a key to achieving clinical control of invasion and metastasis of OTSCC.

High Numbers of Stromal Cancer-Associated Fibroblasts Are Associated With a Shorter Survival Time in Cats With Oral Squamous Cell Carcinoma

Cancer-associated fibroblasts (CAFs) are fibroblastic cells that express α-smooth muscle actin and have been identified in the stroma of numerous epithelial tumors. The presence of CAFs within the tumor stroma has been associated with a poorer prognosis in some human cancers, including oral squamous cell carcinomas (SCCs). Cats frequently develop oral SCCs, and although these are generally highly aggressive neoplasms, there is currently a lack of prognostic markers for these tumors. The authors investigated the prognostic value of the presence of CAFs within the stroma of oral SCC biopsy specimens from 47 cats. In addition, several epidemiologic, clinical, and histologic variables were also assessed for prognostic significance. A CAF-positive stroma was identified in 35 of 47 SCCs (74.5%), and the median survival time (ST) of cats with CAF-positive SCCs (35 days) was significantly shorter than that of cats with CAF-negative SCCs (48.5 days) (P = .031). ST was also associated with the location of the primary tumor (P = .0018): the median ST for oropharyngeal SCCs (179 days) was significantly longer than for maxillary (43.5 days; P = .047), mandibular (42 days; P = .022), and sublingual SCCs (22.5 days; P = .0005). The median ST of sublingual SCCs was also shorter compared with maxillary SCCs (P = .0017). Furthermore, a significant association was identified between site and the presence of stromal CAFs (P = .025). On the basis of this retrospective study, evaluating the tumor stroma for CAFs in feline oral SCC biopsy specimens may be of potential prognostic value.

Expression of MMP-1/PAR-1 and patterns of invasion in oral squamous cell carcinoma as potential prognostic markers

Background

Matrix metalloproteinase (MMP)-1 degrades type I collagen of the extracellular matrix and also activates protease activated receptor (PAR)-1 to induce angiogenesis. The aims of this study were to evaluate microvessel density (MVD) and the expression of PAR-1 and MMP-1 in oral squamous cell carcinoma (SCC) specimens with different patterns of invasion (POI) and to evaluate their association with clinical outcomes.

Methods

Seventy-four surgically obtained oral SCC samples were classified by POI according to hematoxylin-eosin staining. MVD and the localization and intensity of PAR-1 and MMP-1 expression were detected by immunohistochemistry.

Results

Of the 74 oral SCC samples, 18, 5, 34, and 17 showed type I, II, III, and IV POI, respectively. MVD and expression levels of MMP-1 and PAR-1 differed between POI types I–II and POI types III–IV. Patients with low tumor expression of MMP-1 and PAR-1 and low MVD had a longer survival time than those with high tumor expression of MMP-1 and PAR-1. Moreover, the survival time of patients with POI types III–IV was shorter than that of patients with POI types I–II.

Conclusion

POI combined with expression levels of MMP-1 and PAR-1 may be a valuable tool for assessing the clinical prognosis of patients with oral SCC.

Evaluation of histomorphological and immunohistochemical parameters as biomarkers of cervical lymph node metastasis in squamous cell carcinoma of oral cavity: A retrospective study

Introduction:

Oral squamous cell carcinoma (OSCC) is seen worldwide but is more common in India. Lymph node (LN) metastasis has been shown to be the strongest prognostic factor in OSCC. Many histopathological and immunohistochemical markers have been studied to predict the LN metastasis.

Aims:

To identify clinicopathological factors and immunohistochemical (IHC) biomarkers which predict cervical metastasis in OSCC patients.

Study and Design:

A total of 105 cases of OSCC were taken up for our study. Histopathological parameters such as tumor thickness, depth, degree of differentiation, pattern of invasion (POI), lymphovascular and neural invasion were assessed. IHC was done on all cases using antibodies against Ki-67, cyclin D, E-cadherin, p53, CD31 and each antibody was assessed according to the standard protocol.

Statistical Analysis:

To calculate the relation between clinical, histopathological parameter, IHC marker and the occurrence of LN metastasis, chi-square test was used. Variables were tested using multivariate logistic regression method to assess the predictive significance.

Results:

Out of 105 cases studied, 29 cases showed LN metastasis. Maximum numbers of cases affected were females with involvement of buccal mucosa. We found significant association of cervical LN metastasis with high grade of differentiation, lack of E-cadherin expression, high Ki-67 and cyclin D1 expression. In our study; tumor depth, thickness, extent of peritumoral lympho-plasmacytic infiltration, presence of eosinophils, tumor nest type, p53 and microvessel density (MVD) showed no significant correlation.

Conclusion:

Significant association of cervical LN metastasis with high grade of differentiation, lack of E-cadherin expression, high Ki-67 and cyclin D1 expression was seen.

Tumour budding in head and neck squamous cell carcinoma - a systematic review

Tumour budding is a specific type of invasive growth in carcinomas characterized by invading single tumour cells or small clusters of tumour cells (<5 cells) at the invasive front (IF). It has been documented in numerous publications during the past few decades, but its value as a prognostic marker in head and neck squamous cell carcinoma (HNSCC) has been analysed only recently. In this review we aimed to address the question of whether or not tumour budding has an impact upon the progression and prognosis of HNSCC. We systematically reviewed the databases of PubMed, Scopus and Web of Science for articles that studied tumour budding in squamous cell carcinoma of the head and neck region. The search was limited to articles published in the English literature before March 2014. A total of 122 hits were retrieved; however, only five reports met the inclusion criteria. The findings of these reports suggested a strong association between tumour budding and tumour progression, in addition to strong correlation with patient prognosis. Standardization of the scoring method and the risk stratification cut-off point is necessary before the inclusion of tumour budding in pathological reports during daily practice.

Reciprocal relationship of Tn/NF-κB and sTn as an indicator of the prognosis of oral squamous cell carcinoma

AIMS

In order to determine whether the expression of tumour-associated carbohydrate antigens (Tn/sTn) and a representative inflammation marker, nuclear factor-κB (NF-κB), is associated with the invasiveness of oral squamous cell carcinoma (OSCC), this study has attempted to investigate the correlation of the aforementioned markers with the well-established invasive pattern grading score (IPGS) and clinicopathological parameters.

METHODS AND RESULTS

Specimens from 143 OSCC patients with classified clinicopathological parameters and IPGS were stained immunohistochemically using anti-Tn, sTn and NF-κB antibodies. Our results showed that the expression of both Tn and NF-κB was correlated positively with staging (P = 0.036; P = 0.015), recurrence (P < 0.001; P < 0.001) and distant metastasis (P = 0.005; P = 0.009), as well as with IPGS, while the expression of sTn was correlated inversely. In addition, poor survival was associated with overexpression of Tn and NF-κB but not with expression of sTn.

CONCLUSIONS

Our results indicate that a reciprocal relationship between Tn and sTn expression may serve as a reliable indicator for OSCC prognostic evaluation. In addition, expression of Tn rather than sTn may play an important role in deeply invasive OSCC via regulation of NF-κB signalling.

Depth of invasion, tumor budding, and worst pattern of invasion: prognostic indicators in early-stage oral tongue cancer

Background

Oral (mobile) tongue squamous cell carcinoma (SCC) is characterized by a highly variable prognosis in early-stage disease (T1/T2 N0M0). The ability to classify early oral tongue SCCs into low-risk and high-risk categories would represent a major advancement in their management.

Methods

Depth of invasion, tumor budding, histologic risk-assessment score (HRS), and cancer-associated fibroblast (CAF) density were studied in 233 cases of T1/T2 N0M0 oral tongue SCC managed in 5 university hospitals in Finland.

Results

Tumor budding (≥5 clusters at the invasive front of the tumor) and depth of invasion (≥4 mm) were associated with poor prognosis in patients with early oral tongue SCC (hazard ratio [HR], 2.04; 95% confidence interval [CI], 1.17–3.55; HR, 2.55; 95% CI, 1.25–5.20, respectively) after multivariate analysis. The HRS and CAF density did not predict survival. However, high-risk worst pattern of invasion (WPOI), a component of HRS, was also an independent prognostic factor (HR, 4.47; 95% CI, 1.59–12.51).

Conclusion

Analyzing the depth of invasion, tumor budding, and/or WPOI in prognostication and treatment planning of T1/T2 N0M0 oral tongue SCC is recommended.

The paracrine effect of cancer-associated fibroblast-induced interleukin-33 regulates the invasiveness of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the leading causes of cancer-related death worldwide. The prognosis of HNSCC is usually poor because of its propensity for extensive invasion, local recurrence and frequent regional lymph node metastasis, even at initial diagnosis. Carcinoma-associated fibroblasts (CAFs), a major type of tumour-surrounding stromal cell, generate mediators through which they interact with tumours and contribute to cancer progression. The orchestration between CAFs and cancer cells is complex. Despite recent studies demonstrating the paracrine effect of stromal cells in the tumour microenvironment on initiation and progression of cancer cells, the major mediator related to CAFs and its underlying mechanism remain unknown. In the present study, we used organotypic culture to investigate CAFs that promote aggressive behaviour of HNSCC cells. Using microarray analysis, we detected abundant expression of interleukin-33 (IL-33) in CAFs and identified IL-33 as a critical mediator in CAF-induced invasiveness. Counteracting IL-33 activity diminished the aggressive phenotype of cancer cells induced by CAFs. Administration of IL-33 promoted cancer cell migration and invasion through induction of epithelial-to-mesenchymal transdifferentiation and increased IL-33 gene expression in cancer cells. In 40 patients with HNSCC, IL-33 expression in CAFs correlated with IL-33 expression in cancer cells. Most cases with a low invasion pattern grading score (IPGS) showed low or no expression of IL-33, whereas most HNSCC cases with high IPGS displayed over-expression of IL-33 in CAFs and cancer cells. High IL-33 expression associated with poor prognosis in terms of nodal metastasis-free survival. These results indicate that CAFs promote cancer invasiveness via paracrine and autocrine effects on microenvironmental IL-33 signalling, and suggest that IL-33 is a potential prognostic biomarker that could be considered in therapeutic strategies for the treatment of patients with HNSCC.

Loss of CD151/Tspan24 from the complex with integrin α3β1 in invasive front of the tumour is a negative predictor of disease-free survival in oral squamous cell carcinoma

OBJECTIVES

The study aimed to assess the role of CD151-integrin α3β1 (INGA3) complex as a potential prognostic indicator in OSCC and to examine whether mapping of its expression in the invasive front separately from that in the rest of the tumour would have an impact on the predictive value of the results. CD151/INGA3 profiles were compared with that of EGFR.

MATERIALS AND METHODS

Protein distributions were analysed either in the whole tumour (W) or separately, (i) the main tumour mass (TU) and (ii) the invasive front (IF) in 83 OSCC samples using immunohistochemistry.

RESULTS AND CONCLUSION

There was no statistical association between any of the proteins scored in W and clinicopathologic features or patient survival. When examined separately, significant associations were shown for (i) CD151 and EGFR in TU (p=0.036) and (ii) tumour grade and EGFR in both TU (p=0.045) and IF (p=0.030). INGA3 was present predominantly in the tumour-host interface, significantly stronger in IF than TU (p=0.021). An association with 5-year disease-free survival was close to significant for INGA3 (TU and IF) (p=0.050) but not the CD151/INGA3 complex. Expression of CD151/INGA3 at the IF might reflect tumour behaviour pertinent to patient outcome.

Salivary level of interleukin-8 in oral precancer and oral squamous cell carcinoma

BACKGROUND

Interleukin 8 (IL-8) is a pro-angiogenic, pro-inflammatory mediator that belongs to the family of chemokines. Due to its pro-angiogenic characteristic, it may play a vital role in tumour angiogenesis and progression.

OBJECTIVES

This study was designed to estimate the levels of salivary IL-8 in oral precancer and oral squamous cell carcinoma (OSCC) patients and compare them with healthy controls. The aim was to evaluate its efficacy as a potential biomarker for these diseases.

MATERIALS AND METHODS

Each group comprised 25 individuals. The salivary IL-8 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

The levels of salivary IL-8 were found to be significantly elevated in patients with OSCC as compared to the precancer group (p < 0.0001) and healthy controls (p < 0.0001). However, the difference in salivary IL-8 concentrations among the precancer group and controls was statistically non-significant (p = 0.738).

CONCLUSIONS

Our results suggested that salivary IL-8 can be utilised as a potential biomarker for OSCC. Salivary IL-8 was found to be non-conclusive for oral premalignancy in this preliminary study. Hence, its possible role in transition from premalignancy to malignancy needs further research with larger sample sizes.

CLINICAL RELEVANCE

Saliva as a diagnostic biofluid offers a number of advantages over blood-based testing. The role of IL-8 in oral cancer if validated further by future research can provide an easy diagnostic test as well as a prognostic indicator for patients undergoing treatment. Therefore, if it's role in tumourigenesis can be sufficiently assessed, it could open up new avenues to find out novel treatment modalities for oral cancer.

Correlation between metabolic tumor volume and pathologic tumor volume in squamous cell carcinoma of the oral cavity

PURPOSE

To explore the relationship between pathologic tumor volume and volume estimated from different tumor segmentation techniques on (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in oral cavity cancer.

MATERIALS AND METHODS

Twenty-three patients with squamous cell carcinoma of the oral tongue had PET-CT scans before definitive surgery. Pathologic tumor volume was estimated from surgical specimens. Metabolic tumor volume (MTV) was defined from PET-CT scans as the volume of tumor above a given SUV threshold. Multiple SUV thresholds were explored including absolute SUV thresholds, relative SUV thresholds, and gradient-based techniques.

RESULTS

Multiple MTV's were associated with pathologic tumor volume; however the correlation was poor (R(2) range 0.29-0.58). The ideal SUV threshold, defined as the SUV that generates an MTV equal to pathologic tumor volume, was independently associated with maximum SUV (p=0.0005) and tumor grade (p=0.024). MTV defined as a function of maximum SUV and tumor grade improved the prediction of pathologic tumor volume (R(2)=0.63).

CONCLUSIONS

Common SUV thresholds fail to predict pathologic tumor volume in head and neck cancer. The optimal technique that allows for integration of PET-CT with radiation treatment planning remains to be defined. Future investigation should incorporate biomarkers such as tumor grade into definitions of MTV.