The evaluation of sequential type or de novo type in 100 cases of oral squamous cell carcinoma

Abstract

Objectives Oral potentially malignant disorders (OPMDs) have been suggested as oral precancers, including both oral precancerous regions and oral precancerous conditions. Oral squamous cell carcinoma (OSCC) is divided into 2 types according to the appearances of the cancerous regions. One type is carcinomas with precancerous white lesions—the sequential type. The other type is accompanied SCC without precancerous white lesions—the de novo type. The aim of this study was to evaluate the clinicopathologic characteristics in the sequential type and the de novo type of OSCC. Study Design We analyzed 100 cases of OSCC of the tongue diagnosed at Jichi Medical University. We divided these OSCC cases into 2 types, using intraoral photographs taken by an oral surgeon. Statistical analysis was done by using the χ2 test (P Results Of the 100 cases, there were 51 cases of the sequential type (51%) and 49 cases of the de novo type (49%). The percentage of the T1+T2 group (92.2%) in the sequential type was considerably higher than that of T3+T4 group (7.8%). In the de novo type, the T1+T2 group showed 77.6% and the T3+T4 group showed 22.4%. The percentage of lymph node metastasis in the negative group (84.3%) in the sequential type was higher than that of the positive group (15.7%). In the de novo type, the lymph node metastasis–negative group showed 65.3% and the positive group showed 34.7%. These were significant differences. With regard to postoperative lymph node metastasis and the Yamamoto-Kohama classification of modes of invasion, there were no significant differences in the sequential type and the de novo type. With regard to pathologic findings, the margins of the cancerous lesions in the sequential type tended to be connected to dysplasia or oral intraepithelial neoplasia. It also showed the unclear margin. However, it showed clear margins in the de novo type. Conclusions In this study, we found that patients with sequential type tended to seek treatment in T1+T2 (early stages) and to have no lymph node metastasis, compared with the cases of the de novo type. Our results suggested that there was a relationship between the sequential type and OPMDs.