Abstract
Background
The grading of oral epithelial dysplasia is not possible in the atrophic epithelium of oral submucous fibrosis (OSMF). Recently, we found that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, increased nuclear size, and hyperchromasia represent transformation-relevant dysplastic features in the atrophic epithelium of OSMF. The presence of these features can be considered a high-risk feature for patients. However, these findings have not been tested and authenticated using markers relevant to oral carcinogenesis.
Method
Paraffin-embedded tissues from 30 normal oral mucosa (NOM) and 50 OSMF were retrieved from 2008 to 2016 and subjected to immunohistochemical expression using Ki67, CD105 and alpha-SMA antibodies.
Results
Ki67 LI showed significant increases from NOM (12.47 +/- 2.34) to LRED (23.47 +/- 3.75) to HRED (34.31 +/- 7.31) (<0.0001). Similarly, MVD was increased significantly from NOM (3.53 +/- 5.17) to LRED (27.57 +/- 12.25) to HRED (46.18 +/- 12.55) (p<0.0001). The expression of alpha-SMA was significantly increased from LRED (0.21 +/- 0.41) to HRED (1.13 +/- 0.56) (<0.0001). The Ki67 LI and alpha-SMA; MVD and alpha-SMA; and Ki67Ki67 LI and MVD in NOM, LRED and HRED showed a statistically significant positive correlation (P<0.0001). The increase in Ki67 LI was directly proportional to MVD and alpha-SMA expression from NOM to LRED to HRED (P<0.0001). The connective tissue stroma of NOM lacks alpha-SMA expression. Mild myofibroblast expression was noted in 4 cases of LRED (14.28%) and in 18 cases of HRED (81.81%). Moderate expression was noted only in 4 cases of HRED (22.22%).
Conclusion
Ki67 LI, CD105, and alpha-SMA expression showed significant differences between normal, LRED and HRED. These findings further support that features such as increased basal cell layer hyperplasia, abnormal superficial mitosis, increased nuclear-cytoplasmic ratio, and hyperchromasia could be transformation-relevant dysplastic features.