Diagnostic Value of Cytokeratin 17 during Oral Carcinogenesis: An Immunohistochemical Study

Background. Little is known about the role of cytokeratin 17 (CK17) during oral carcinogenesis. CK17 expression in oral leukoplakia (OL), the most encountered oral potentially malignant disorders and oral squamous cell carcinoma (OSCC), remains very limited. To determine the role of CK17 during oral carcinogenesis and its potential diagnostic marker in oral premalignant and malignant lesions, this study evaluated CK17 expression in OL without dysplasia, OL with dysplasia, and OSCC. CK17 expression in these tissues was compared with those of normal oral mucosa (NOM). Additionally, the relationship between CK17 expression and clinicopathologic factors of OSCC was investigated. Methods. CK17 expression was evaluated in 186 samples consisting of 12 NOM, 33 OL without dysplasia, 58 OL with dysplasia, and 83 OSCC using immunohistochemistry. The proportion of positively immunostained cells was evaluated and scored. Results. CK17 was expressed in 8.3%, 54.5%, 74.1%, and 90.4% of NOM, OL without dysplasia, OL with dysplasia, and OSCC, respectively. NOM had a significantly lower CK17 score than OL with dysplasia ( p = 0.0003 ) and OSCC ( p < 0.0001 ). A significant association between CK17 expression and histopathologic differentiation of OSCC was found. Tumors with well differentiation had high CK17 expression compared with those of moderate and poor differentiation. Conclusion. CK17 was overexpressed in OL with dysplasia and OSCC, suggesting that CK17 plays a pivotal role in the development of premalignant lesions and OSCC. Of clinical significance, CK17 may be a good diagnostic marker for oral premalignant lesions and OSCC. Additionally, CK17 could be used as an objective tool to classify histopathologic grade in OSCC. The findings that CK17 expression is high in OSCC but low in NOM imply that CK17 may serve as a potential therapeutic target for OSCC.

Diagnostic utility of Cytokeratin 13 and Cytokeratin 17 in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Objective: To determine the immunohistochemical expression of CK 13 and CK 17 in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma. Methods: A total of 170 cases were retrieved from record files of Histopathology Department, to conduct a cross sectional study at Armed Forces Institute of Pathology, Rawalpindi, over a period of one year from June 2018 to June 2019 along with their formalin-fixed, paraffin embedded blocks comprising 85 cases of each oral squamous cell carcinoma and oral epithelial dysplasia. Blocks were trimmed and cut into very thin sections of 5 microns using microtome and mounted on slides. Tissue mounted slides were stained with routine haematoxylin and eosin followed by immunohistochemical staining of cytokeratin 13 and cytokeratin 17. New histological diagnosis of each case was made. Mean and standard deviation were calculated for quantitative variables. Frequency and percentages were calculated for qualitative variables. Chi-square test was employed to assess the significance of difference. The P-value <0.05 was considered significant. Results: In this study, 101 (59.4%) male and 69 (40.6%) female patients with the mean age of 60.63 ± 13.814 (mean ± SD) were collected and buccal mucosa was the most common site of presentation. In a total of 170 cases, 34 (20%) cases showed positive expression of cytokeratin 13 whereas 136 (80%) cases showed negative expression of cytokeratin 13. In comparison, out of 170 cases, 133 (78.2%) cases showed positive expression of cytokeratin 17 whereas 37 (21.8%) cases showed negative expression of cytokeratin 17. The P-value was found to be < 0.001 and 0.001 for expression of cytokeratin 13 and cytokeratin 17 respectively. Conclusion: Opposite expression of cytokeratin 13 and cytokeratin 17 was seen in this study, in the form of loss of cytokeratin 13 and over expression of cytokeratin 17 with increase in the degree of dysplasia and invasive carcinoma. Correct assessment, diagnosis and management with the help of these markers can lead to early diagnosis and favorable treatment outcome.

Distribution of Cytokeratin 17 in the Parenchymal Elements of Rat’s Submandibular Glands Subjected to Fractionated Radiotherapy

Objectives The aim of this research was to study the intensity of cytokeratin 17 (CK17) in the parenchymal elements of rat’s submandibular salivary glands subjected to fractionated radiotherapy regimen that used for treatment of head and neck malignancy. Materials and Methods Twenty male albino rats were divided into two equal groups (normal and irradiated). The irradiated group received a radiation dose of 5 Grays daily for 5 days using therapeutic X-ray beam. Six months later, submandibular gland was dissected out and prepared for both histological and immunohistochemical studies. Results Submandibular gland of irradiated group showed two different types of histological alterations. The first alteration showed severe gland atrophy replaced by either fibrous or fatty tissues. In some sections, the gland exhibited proliferating activity in the form of profuse amounts of mitotic figures. Immunohistochemical examination of control glands displayed a mild cytoplasmic expression of CK17 of duct cells as well as serous acini. The staining pattern was either diffused or concentrated at the basal part of the cell with negative expression at its apical part. Statistical Analysis Expression of CK17 in submandibular gland of irradiated group displayed a highly significant differences (P < 0.001) in both intercalated and striated ducts. Many serous acini displayed a highly significant differences (P < 0.001) whereas, mucous acini were negatively stained. Conclusions The intensity and diffusion of CK17 expression in our results foretell the pathological effect of radiotherapy on the intermediate filaments of salivary gland parenchyma that interfered with production and/or secretion of saliva leading to xerostomia.