Paraffin-embedded Formalin-fixed Specimens Research Articles

High Prevalence of Human Papillomavirus Type 18 in Oral Potentially Malignant Disorders in Thailand.

Objectives:The main objectives of this study were to investigate the detection rate of high-risk human papillomavirus types 16 and 18 (high-risk HPV16/18) in oral potentially malignant disorders (OPMDs) including oral leukoplakia (OL) and oral lichen planus (OLP) in a Thai population and their associations with demographic, risk habits, and clinicopathologic features. Methods:Paraffin-embedded formalin-fixed specimens from 101 OL and 59 OLP patients with patients’ demographic, risk habits, and clinicopathologic data were collected. Conventional qualitative polymerase chain reaction was used to detect high-risk HPV16/18 DNA. Associations between high-risk HPV type 16/18 and demographic, clinicopathologic, risk factors (tobacco and alcohol uses) of OPMDs were analysed by Chi-square or Fisher’s exact test. The results with p value less than 0.05 were considered statistically significant. Results:HPV16/18 DNA was found in both OL and OLP groups with the detection rate of 19.8% and 18.6%, respectively. Approximately 90% of high-risk HPV were HPV18 subtype. Additionally, in OL group, high-risk HPV was found more frequently in patients with moderate/severe dysplasia than that in mild dysplasia. Interestingly, in OLP group, high-risk HPV was only detected in atrophic/ulcerative subtypes. None of risk factors was associated with high-risk HPV. Conclusions:Approximately 19% of OPMDs were HPV16/18-positive. HPV18 DNA was predominantly detected in both OL and OLP patients (90%). Additionally, the detection rate of high-risk HPV was higher in more severe dysplastic cases of OL and more clinically severe cases of OLP.

Tenascin-C Expression and Its Prognostic Significance in Colorectal Cancer

Objective: The extracellular matrix glycoprotein tenascin-C has been proposed as a tumor marker with prognostic significance in many cancer forms, but in colorectal cancer, reported results have been controversial. The aim of this study was to evaluate the prognostic value of immunohistochemical tenascin-C expression in a series of 231 patients with colorectal cancer. Methods: Paraffin-embedded formalin-fixed specimens were stained with a tenascin-C-specific monoclonal antibody, and the stromal staining intensity and pattern were analyzed. Results: Tenascin-C immunoreactivity was observed in all 231 specimens, with a pattern of staining that was diffuse and interstitial. The staining was occasional in 39 (17%), moderate in 106 (46%) and strong in 86 specimens (37%). There was no statistically significant association between tenascin-C immunoreactivity and any of the other clinicopathological variables. The cumulative 5-year survival rates of patients with occasional and weak staining were similar (56.8 and 54.9%, respectively), while the patients with strong tenascin-C staining had a lower survival rate (46.1%). This difference in survival was not significant (p = 0.23). The staining pattern and distribution can be viewed from digitized representative microscope slides (virtual slides) at http://www.webmicroscope.net/supplements/tenascin. Conclusions: Our results indicate that immunohistochemical expression of tenascin-C is not of prognostic significance in colorectal cancer.

Epithelial Syndecan-1 Expression Is Associated with Stage and Grade in Colorectal Cancer

Objectives: Loss of epithelial heparan sulfate proteoglycan syndecan-1 has been associated with a more aggressive behavior in various cancer forms, but the prognostic significance of syndecan-1 expression in colorectal cancer is unclear. The aim of this study was to evaluate the prognostic value of immunohistochemical syndecan-1 expression in a series of 237 patients with colorectal cancer. Methods: Paraffin-embedded formalin-fixed specimens were stained with a syndecan-1-specific monoclonal antibody, and both the epithelial and stromal expression were analyzed. Results: Epithelial expression of syndecan-1 was seen in 222 tumors (94%), and it was associated with low stage of disease (p = 0.002) and low histological differentiation grade (p = 0.048). The cumulative 5-year survival of patients with weak and strong syndecan-1 expression was 49 and 54 %, respectively (p = 0.234). Syndecan-1 stromal immunoreactivity was observed in 138 tumors (58%), but lacked prognostic significance. Staining pattern and distribution can be viewed from digitized representative microscope slides (virtual slides) at http://www.webmicroscope.net/supplements/syndecan. Conclusions: The results are in line with previous reports in that low epithelial syndecan-1 expression was associated with a higher histological grade and a more advanced clinical stage of the patients. This study shows that syndecan-1 is expressed also in stromal tissue of colorectal cancer, but it does not support the proposed role of stromal syndecan-1 expression as a marker of poor clinical outcome.