Abstract 82P
Background
The high-risk human papillomaviruses (HPVs) and the Epstein-Barr virus (EBV) are potent oncoviruses. Yet, their role in colorectal cancer (CRC) is still dubious. This study emerges as the first report on HPV and EBV prevalence/co-prevalence in Qatar and the Gulf Cooperation Council (GCC) region, delineating the link between oncoviral synergy and advance stage CRC. This study aimed to explore co-presence of high-risk HPVs and EBV and their implied cooperation in modulating the expression of epithelial-mesenchymal transition (EMT) biomarkers (fascin/vimentin/epithelial protein lost in neoplasm), that are strongly linked to tumor-progression and metastasis.
Methods
This study analysed 100 tumor samples from CRC patients. Polymerase chain reaction-based genotyping of the oncoviruses was performed. Construction of the tissue microarray was achieved for 80 samples. Immunohistochemical evaluation was carried out to determine the expression levels of the EMT biomarkers. Staining intensity was analysed via a semi-quantitative scoring method. A total score was computed based on the sum of the individual scores for each EMT biomarker. A score ≥ 10 was coded as a high tumor score. Pearson's Chi-square test and logistic regression were calculated to estimate an association between HPV and EBV co-infection and a high tumor score.
Results
High-risk HPVs and EBV are present in 66.2% and 21.2% cases, respectively. Additionally, 16.3% were co-infected with both oncoviruses. The co-infection of high-risk HPVs strongly correlates with advanced stage cancer, and EBV is a strong confounder of this association. In the present investigation, 69.2% of the co-infected samples showed a high score for the expression of EMT biomarkers. Thus, co-infected patients are at 7.2 times greater odds of presenting with a high tumor score (p = 0.002); thereby implying a worse prognosis.
Conclusions
Evidently, the co-infection of oncoviruses is a strong prognostic indicator of advanced stage CRC. Also, oncoviral co-infection can favour EMT, and consequently tumor-progression/metastasis. Further research is essential to confirm the synergistic roles of oncoviruses in the pathogenesis of cancer.
Legal entity responsible for the study
Qatar University.
Funding
Qatar University.
Disclosure
All authors have declared no conflicts of interest.