Present status and controversial issues in the treatment of carcinoma of the lower gun in a questionnaire survey

Abstract

As a first step toward making a guideline for the treatment of carcinoma of the lower gum, a questionnaire survey was conducted in order to identify the present status of the treatment in Japan. The results and controversial issues of 86 respondents are reported.
A total of 2986 cases of carcinoma of the lower gum were treated in the 86 institutions in the past 10 years (1993-2002) . T4 cases amounted to one-third of them (1016 cases) . As a T4 criterion, the level of mandibular canal criteria was accepted in 57 institutions (65.5% ) . On the other hand, only 34 institutions (39% ) accepted deep invasion into soft tissue as a T4 criterion together with mandibular invasion. Therefore, standardization of T4 criteria seems to be the first priority in making the guideline.
Tumor size, bone invasion and depth, and bone invasion pattern were regarded in almost all the institutions as one of the factors of indication of mandibulectomy (marginal and segmental resection) which is the most important issue in the treatment of carcinoma of the lower gum. However, the practical criteria of the indication for mandibulectomy vary considerably among the institutions. Thus, standardization of the criteria of the indication for mandibulectomy is a necessary but difficult task for making the guideline.