Cytokeratin 13, Cytokeratin 17, Ki-67 and p53 Expression in Upper Layers of Epithelial Dysplasia Surrounding Tongue Squamous Cell Carcinoma.

Early detection of oral squamous cell carcinoma (OSCC) improves its prognosis and aids in selecting the appropriate treatment, which may also have a positive effect on quality of life. Early detection, therefore, is an important issue in the treatment of this disease. The purpose of this study was to investigate expression of cytokeratin 13 (CK13), CK17, Ki-67 and p53 as potential markers of tongue SCC. Five areas in 12 specimens were examined: the upper and lower layers of normal epithelium; those of dysplastic epithelial tissue surrounding the cancerous lesion; and the lesion itself. Strong expression of each of the following mRNAs and proteins was observed; CK13 in upper layers of normal epithelium; Ki-67 and p53 in lower layers of normal epithelium; CK13 and CK17 in upper layer of epithelial dysplasia; and CK17, Ki-67, and p53 in lower layer of epithelial dysplasia and cancerous lesions. These results indicate that the characteristic pattern of expression of CK13 and CK17 differs between normal and dysplastic oral epithelium. Oral epithelial dysplasia adjacent to OSCC has high malignant potential, and is similar to early-stage OSCC. This suggests that evaluation of these markers could be a useful secondary procedure for improving detection of early-stage OSCC.

A 5-year activity report from the Oral Cancer Center, Tokyo Dental College.

The Tokyo Dental College Oral Cancer Center was established on April 1st, 2006 at our Ichikawa General Hospital for the purpose of providing multimodal treatment for oral cancer. This report summarizes the Center's activities over the last 5 years. The total number of oral cancer patients treated was 360 (April 2006 to March 2011), with 205 primary cases. We investigated the following treatment-related items: 1) site, 2) age, 3) sex, 4) pathological examination, 5) staging, 6) systemic disorder, 7) double cancer, 8) treatment, and 9) prognosis. Out of 205 patients, 60% were men and 40% were women. Men in their 60s and women in their 80s were seen the most. The most common site was the tongue, at 42%, followed by the mandibular gingiva, maxillary gingiva, oral floor, and buccal mucosa. Squamous cell carcinomas were seen most frequently, at 94% (15% were stage I, 33% stage II, 15% stage III, and 34% stage IV). The most common treatment method was surgical treatment, at 83%. The 5-year survival rate at all stages was 85.4%. At the Oral Cancer Center, oral surgeons take the initiative in establishing treatment in cooperation with other departments and branches. Since the establishment of the Ambulatory Center for Maxillary Prosthetics in October 2011, 26 patients have undergone treatment. Related departments and branches work in teams, enabling comprehensive treatment, from the preoperative state to postoperative functional recovery. We wish to use these strengths to improve oral cancer treatment in Japan and will continue to work toward providing the best possible care for our patients.

Expression of myelin and lymphocyte protein (MAL) in oral carcinogenesis.

In the pathological diagnosis of oral squamous cell carcinoma, we often confront the difficulty of determining whether it is invasive carcinoma or epithelial dysplasia. Recently, myelin and lymphocyte protein (MAL; T-cell differentiation-related gene) has been reported to be a candidate gene suppressed in esophageal carcinoma. When we performed cDNA microarray analysis, we found that gene expression of MAL was significantly downregulated in oral squamous cell carcinoma (OSCC). We evaluated the expression of the MAL gene by laser microdissection and real-time PCR methods and protein localization by immunohistochemistry. The gene expression of MAL was significantly decreased in OSCC compared with normal epithelium (P < 0.05). Furthermore, protein expression of MAL disappeared gradually in proportion to malignancy. The results suggest that MAL plays an important role during oral carcinogenesis and that the gene may have potential as a biomarker target for OSCC.