No abstract

With the identification of a number of novel markers having diagnostic, prognostic, and therapeutic significance, the application of tissue microarray (TMA) has become a valuable tool for validating candidate markers in cancer research. The TMA is a high-throughput technique, which allows large-scale analyses of hundreds of archival clinical tissue samples using the 'array' approach. This paper highlights briefly its robust technology, technical aspects of its construction, and the validity of the TMA results for oral pathology diagnostics by reviewing data from recent literature particularly with reference to head and neck cancer.

Osteoid osteoma is a benign skeletal neoplasm most frequently observed in young individuals. The tumor most commonly occurs in the femur, the tibia, and the phalanges; however, jaw lesions are very rare. Herein, we report a rare case of osteoid osteoma that presented in the mandible of a 20-year-old boy. This report also reviews the cases of osteoid osteomas of the jaws that have been reported in the English literature so far.

Oral squamous cell carcinoma (OSCC) is the most common head and neck squamous cell carcinoma (HNSCC) with metastasis and tumor recurrence resulting in 90 % of cancer associated mortality. COX-2, an inflammatory biomarker, has been shown to play a significant role in tumorigenesis of OSCC. To study the expression of COX-2 in OSCC by immunohistochemistry and investigate its association with the clinicopathological parameters including patient survival. A cross sectional study was carried out in 75 histologically confirmed cases of OSCC. COX-2 expression was evaluated by indirect streptavidin biotin method. The expression was semi-quantitatively assessed using established criteria. The expression profile of COX-2 was correlated with the clinicopathological details like tumor size, regional lymphnode metastasis, distant metastasis, clinical stage, local recurrence of tumor, histological grade, and survival of patient. Chi square and Kaplan Meier statistical tests were applied for assessing this association. COX-2 expression was absent in normal oral mucosa. Over expression of COX-2 was seen in 58 out of 75 specimens of OSCC. Overexpression of COX-2 was significantly associated with the lymphnode involvement, histological grade, local recurrence of tumor and patient survival. COX-2 expression represents an important biomarker of prognostic significance that may be used to identify a subset of patients at high risk and to predict patient survival.

Bcl-2 was the most frequently expressed biomarker. The expression of Bcl-2 was inversely related to the degree of differentiation (P = 0.005). The follow-up data showed that 63.6% of the cases that were positive for both Bcl-2 and E-cadherin were disease-free following treatment. Tissue microarray technology is a promising way to analyse multiple biomarkers simultaneously. The molecular data obtained from TMA will enhance diagnosis, provide better prognostication and will improve cancer treatment for individual patients.

Background:Recent studies have indicated that although malignant cells at the invasive tumor front, bare morphological resemblance to the cells at central portion of the tumor, their molecular character differs significantly. E-cadherin is a cell-cell adhesion molecule that connects epithelial cells. This study attempts to correlate the E-cadherin expression at the invasive tumor front with tumor differentiation along with its clinico-pathological parameters.Materials and Methods:Immunohistochemical staining with E-cadherin was carried out on archival cases of primary oral squamous cell carcinomas (n = 30). The E-cadherin expression at the invasive tumor front was analyzed and was linked to clinico-pathological parameters including patient prognosis.Results:The downregulation of E-cadherin expression at the invasive tumor edge when compared with patient's prognosis yielded a significant correlation (P = 0.041) but its correlation with the degree of differentiation determined was not significant (P = 0.27). Also, its association with tumor size and lymph node status was negative.Conclusions:Loss of E-cadherin expression at the invasive tumor front is an important event in the progression of oral squamous cell carcinomas. Tumors with a loss of expression of E-cadherin are those which had a poor prognosis

Oral squamous cell carcinomas comprise a heterogeneous tumor cell population with varied molecular characteristics, which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. This is a retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population. The expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas was evaluated. A potential biomarker that can predict the tumor response to treatment was identified. Formalin-fixed paraffin-embedded tumor blocks of (n = 178) of histopathologically diagnosed cases of locally advanced oral squamous cell carcinomas were selected. Tissue microarray blocks were constructed with 2 cores of 2 mm diameter from each tumor block. Four-micron-thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53, Bcl-2, cyclin D1 and p16. In this cohort, EGFR was the most frequently expressed 150/178 (84%) biomarker of the cases. Kaplan-Meier analysis showed a significant association (p = 0.038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (unadjusted IRR-95% CI 2.08 (1.03, 4.5), adjusted IRR-2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients.

ObjectivesTo determine the prevalence of odontogenic cysts and tumors along with age range, sex distribution, site of presentation and also to identify the most common type of odontogenic cyst and tumor among the population of coastal Karnataka over a 10-year period.MethodsData was collected from patient records and histologically diagnosed cases of odontogenic cysts and tumors. The age, gender of patients, as well as the site of lesion was recorded.ResultsA total of 167 cases were retrieved. Among them, 125 cases were diagnosed as odontogenic cysts and 42 cases were odontogenic tumors. Radicular cyst was the most frequently diagnosed cyst and unicystic ameloblastoma was the most frequently diagnosed tumor. A strong predilection for males was observed for both the odontogenic cysts and odontogenic tumors. Odontogenic cysts were more commonly seen in individuals in the age range 21–41 years, while odontogenic tumors were frequently seen in individuals in the age range 1–20 years.ConclusionThis study provides an epidemiological profile of odontogenic cysts and odontogenic tumors among a rural population of coastal Karnataka. There is a notable variation in demographic profile of odontogenic cysts and odontogenic tumors in this population when compared with other populations.