Clinical study of mode of invasion in tongue squamous cell carcinoma

Abstract

ObjectiveThe most commonly used system of classification for the evaluation of histological malignancy in oral squamous cell carcinoma is the Yamamoto–Kohama (Y–K) classification, which focuses on the shape of tumor cell cords at the tumor–host interface, an item also included in the Jakobsson and Anneroth classifications. In this clinical study, we investigated the relationship between mode of invasion as based on the Jakobsson and Y–K classifications and prognosis in patients with tongue squamous cell carcinoma treated at our department. Patients and methodsOne hundred and sixty-eight of the 193 patients with tongue squamous cell carcinoma treated in at our department over an 11-year period between 2000 and 2010 were included in this study (25 were excluded as the mode of invasion could not be determined according to the Y–K classification). ResultsAccording to the Jakobsson classification, 26, 33, 53, and 56 tumors were classified as grades 1–4, respectively. According to the Y–K classification, 26, 33, 53, 31, and 25 tumors were classified as grades 1–3, 4C, and 4D, respectively. ConclusionPatients with grade 4C/4D tumors had many poor prognostic factors, including a pN-positive rate of 73.5%, mortality, recurrence, and late metastasis rate of 44.2%. The tumors in this group exhibited both endophytic and exophytic growth patterns, and the 5-year-survival rate was significantly lower than that in patients with other grade tumors. These results suggest that grade 4C/4D is a useful prognostic factor.