New proposal for T classification of gingival carcinomas arising in the maxilla.

When the current T classification of the UICC (1987 and 1997) is used to stage carcinomas arising the upper alveolus and gingival and hard palate, most cases are classified as T4 because of their anatomic characteristics, similar to carcinomas arising in the lower alveolus and gingiva. This study compared the following two methods for classifying the T stage of maxillary carcinomas: (1) the original T classification criteria proposed by the UICC (1987 and 1997), and (2) a new T classification criteria, called the sinus and nasal floor (SNF) criteria. We found that the SNF criteria were more closely related to tumor control and survival than were the UICC criteria in patients with carcinomas arising in the upper alveolus and gingival and hard palate. Increased use of the SNF criteria is expected to improve staging of gingival tumors arising in the maxilla and increase the accuracy of diagnosis, especially of T4 tumors.