Histological grading in the deep invasive front of T1 and T2 glottic squamous cell carcinomas has high prognostic value.

The characteristics of the deep invasive front area of squamous cell carcinomas may reflect tumour prognosis better than other parts of the tumour. Consequently, the authors have recently developed a simple malignancy grading system based solely on the characteristics of the deep invasive front area of oral squamous cell carcinomas, which has great prognostic value. Our previous materials were somewhat heterogeneous, and the prognostic value of our system needed to be confirmed in homogeneous patient material. In the present study of 95 T1-2/N0 glottic carcinomas all treated by radiation, the high prognostic value for invasive front grading of biopsy specimens is confirmed. The grading significantly predicted local recurrence, i.e. treatment failure (P = 0.001). Histological characteristics of the deep invasive front proved to be a better indicator of prognosis than the T-category (size of tumour), and our findings may be of value in the selection of treatment. Of the individual variables in the grading system (pattern of invasion, degree of keratinization, nuclear polymorphism and host response), pattern of invasion and degree of keratinization were the strongest prognosticators in the multivariate analyses. Invasive front characteristics may also prove to be of prognostic value in other cancers.