Clinical characteristics of precancerous lesions and early squamous cell carcinoma in the oral cavity

• Published in: Journal of Japanese Society of Oral Oncology Vol. 11; no. 4; pp. 357 - 363
• Main Authors: Negishi, Akihide, Iwaki, Hiroshi, Suzuki, Tetsuo, Miyakura, Takeshi, Uzawa, Shigekazu, Amagasa, Teruo, Ogura, Ichiro, Yamashiro, Masashi, Fujii, Eiji
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Oral Oncology 1999
• Subjects: early squamous cell carcinoma; leukoplakia; malignant transformation; precancerous lesion
• ISSN: 0915-5988; 1884-4995; 1884-4995
• DOI: 10.5843/jsot.11.357

The purpose of this study was to clarify the clinical and histopathological characteristics of oral leukoplakia and its malignant transformation and to delineate the clinical characteristics of early squamous cell carcinoma in order to diagnose oral squamous cell carcinoma in the early stage for a desirable outcome. Four hundred forty-four patients with 601 oral leukoplakias were reviewed. 275 were males and 169 females. The ages ranged from 19 to 83 years. 25% of the 601 lesions were located on the mandible, 24.8% on the tongue, and 20.8% on the buccal mucosa. The lesions were classified into four clinical types, 76.2% into type I (leukoplakia without elevation nor red component), 14% into type II (leukoplakia with red component) . 4.8% into type III (slightly exophitic leukoplakia), and 5% into type N (markedly exophitic leukoplakia) . Malignant transformation rate (MTR) of type II was the highest (21.4%) type and that of the tongue was the highest (16.4%) of all the affected sites. MTR of female, older patients, and the lesions with epithelial dysplasia was higher than that of male, the younger under 50, and the lesions without epithelial dysplasia respectively. MTR after surgery was lower than that after any other treatment or no treatment. Eighty-six patients with 88 early squamous cell carcinomas were examined and sixty-eight of 88 lesions were located on the tongue. As for the clinical type, 34.1% were classified into the mixed type and 21.6% into the leukoplakic and the granular types respectively. A ten-year cumulative survival rate of 86 patients was about 90%.