Search

BACKGROUND Although human papillomavirus (HPV) is considered as a causative factor in oral squamous cell carcinoma (OSCCs), its pathogenetic role is not well established. Moreover, a limited number of studies have compared the techniques of detecting the HPV infection in OSCC. This study aimed at the detection of HPV 16 E6 and E7 DNA in OSCC by quantitative polymerase chain reaction (qPCR) technique. METHODOLOGY This retrospective study included 297 tissue sections obtained from histopathologically confirmed OSCC patients. The classification of tumors as poorly differentiated, moderately differentiated and well differentiated was performed by H&E staining following the WHO criteria for OSCC. The presence of HPV infection was detected by p16INK4A expression, conventional PCR technique, HPV 16 E6, and E7 by qPCR and flow cytometry. All statistical analysis was performed using MedCalc software v.16.4.3. P < 0.05 is considered as statistically significant. RESULTS Of 297 samples, 128 samples were found to be HPV-positive by p16. Of total 128 HPV-positive samples, PCR, E6, and E7 qPCR were positive in 19, 97, and 98 samples, respectively. qPCR techniques were found highly significant in the detection of moderately differentiated (P < 0.0001) and widely differentiated (P < 0.0001) cases. The positivity of E6 qPCR increased as the p16 expression increased. A significant variation in E6 DNA copies was observed in different grades of p16 expression (P < 0.0001). However, overall E7 (5.4 × 105 copies/μL) DNA copies were higher than E6 (7.7 × 103 copies/μL). CONCLUSION qPCR detection of HPV infection is a fast, reliable, and accurate technique gives valuable information about the infection status in terms of viral load.

Context Estimation of time since death is the preliminary step in any postmortem examination. Although there are various physiological methods to conclude the postmortem, interval histological changes can be applied to obtain precision. However, the utility of oral tissues for such an event is still evolving. Aims The present study was conducted to assess the efficacy of postmortem histological changes that occur in tongue to conclude the postmortem interval (PMI). Materials and methods After obtaining institutional human ethical committee, tongue tissue was collected for during routine autopsy procedure. The study comprised twelve autopsied tongue tissues. The tissue specimens were subjected to routine laboratory tissue processing procedure and the histological changes were evaluated. Conclusion This is the first study of this kind in the scientific literature to explore the tongue tissue to estimate the PMI. There were definite changes in the epithelium and the connective tissue of the tongue, and these features were highly remarkable at various postmortem time intervals.

Objectives Oral cancer etiology is multifactorial and the main risk factors are tobacco chewing and smoking along with alcohol consumption and viruses. In the current study from a South Indian population, we sought to determine the role of HPV 16 in the pathogenesis, its concordance with p16 over expression in OSCC. Preliminary examination on FFPE embedded OSCC (n = 297) sample was observed by H & E staining, and cases showing cytological changes were selected. Findings HPV 16 DNA prevalence were assessed by Conventional PCR method which showed 128 out of 297 samples positive for HPV16 DNA. Further, the frequency distribution of HPV 16 E6/E7 in 128 tissues was evaluated by qPCR which showed 97 samples were positive for HPV16 E6 qPCR and 98 samples positive for HPV16 E7 qPCR. For the same 128 samples immunohistochemistry was conducted for p16 evaluation.Out of 128 tissue samples, 19 tissue samples were found to be positive for p16 overexpression (+++). Evaluation of mRNA expression of E6 and E7 in the 19 samples was estimated by flow-cytometry, which revealed only 7 samples positive for the mRNA expression. There was no correlation between p16 expressed (+++) samples and quantification of HPV16 mRNA expressions. From these investigations the role of HPV in the etiology, pathogenesis of OSCC was not established. Conclusion This led to the performance of meta-analysis in which studies pertaining to HPV-related OSCC evaluated by application of conventional and qPCR, flow cytometry and IHC for the detection of DNA, mRNA and p16 overexpression, respectively were included. The results obtained were indicative that HPV prevalence in the oral cavity is low and unlikely to play a major significant or decisive role in the etiology, pathogenesis of OSCC. Our results were in accordance with the meta analysis results.

Purpose HPV is believed to promote the oncogenic process, and the correlation between viral oncoproteins and dysfunction of p16(INK4A) tumor suppressor protein in oral lesions is controversial. Results from recent studies suggest that some of these cancers, primarily those of the oropharynx (and, more specifically, those of the base of the tongue and the tonsils), are associated with infection with high-risk HPV types. The aim was to compare and correlate the P16 protein expression between the oral and oropharyngeal SCCs. Material and Methods Forty-six formalin-fixed and paraffin-embedded biopsy specimens were obtained from the Oral Pathology department, V.S.dental college and hospital, Bangalore and from General Pathology, KIMS, Bangalore. All the samples were archival specimens. Tissues were sectioned and histopathological diagnoses were reconfirmed by two experienced professionals. Of the 46 lesions, 20 were oral SCCs, and twenty were from the oropharyngeal carcinomas. Six controls were used, 3 positive control, i.e., cases from cervical carcinoma and three negative controls, i.e cases from normal oral mucosa, and were subjected to IHC. The IHC expression of p16 was quantified in a double-blind protocol and classified according to nuclear and cytoplasmic positivity. The scoring was considered as positive when more than 5% cells (cut-off) stained positively, and was graded as described by Klaes et al. A correlation between p16 expression and histopathological features was done. Results Fourteen (70%) of 20 oralpharyngeal lesions were p16-positive and 8 (40%) of oral lesions were p16 positive. The IHC expression results were analyzed by the probability tests, with (P less than 0.05) being considered statistically significant. Conclusions These results showed overexpression of p16 protein in oral and oropharyngeal lesions, more so in the latter and this has to be correlated with HPV association to suggest that p16 may serve as a biomarker in oral and oropharyngeal cancer.