[Mouth floor and mobile tongue epidermoid carcinomas thickness: prognostic value]

Most cancers of the oral cavity are epidermoid carcinomas. The prognosis is made on the patient's general health status and the tumoral stage. The UICC TNM staging classification system is one of the most important factors taken in consideration for the prognosis. But this classification in oral epidermoid carcinomas does not include the tumor thickness (except for T4 tumors). Several studies demonstrated that tumor thickness could influence the prognosis in epidermoid carcinoma and other types of cancers. The aim of our retrospective study was to assess the prognostic value of tumor thickness in oral epidermoid carcinoma.

The study included patients with mouth floor or mobile tongue epidermoid carcinoma classified T1N0, T2N0 and T3N0 between 1985 and 2005. All patients were treated with a curative intention. A pathologist analysed the tumor thickness and cervical lymph nodes. All the slides were examined to measure tumor thickness in millimetres.

Three hundred and five patient files were reviewed and 124 patients were included, with 94 men (75.8%), and a mean age of 59.3 years (17-93). The mean and median tumor thickness were respectively 7.7 and 6.5 mm (0.4-30). The median tumor thickness was chosen for the study. There was a statistically significant link between the five-year probability of global survival and the initial tumor thickness and between neck node invasion and tumor thickness (p<0.05).

This study suggests that tumor thickness should be taken in consideration in T1N0, T2N0 and T3N0 mouth floor and mobile tongue epidermoid carcinomas. In the future, the clinical evaluation of tumor thickness will help determine the therapeutic management.