Prognostic implications of malignancy grading of invasive fronts of oral squamous cell carcinoma

Invasive front malignancy grading system in oral squamous cell carcinoma (OSCC) introduced by Bryne et al. is reported to be of prognostic significance in a number of studies conducted in Western countries. The aim of this study was to evaluate the prognostic significance of the modified Bryne's malignancy grading system and to compare it with the World Health Organization (WHO) grading system in the Indian population.

The records of 50 patients diagnosed with primary OSCC were evaluated. Only large surgically resected specimens that had deep invasive fronts in the cut sections were selected. All hematoxylin and eosin-stained slides were analyzed by two grading systems: the WHO grading system and the Bryne's malignancy grading of the deep invasive fronts of OSCCs.

Histopathologic grading in the invasive sites had highly significant prognostic value and had significant correlation with overall survival rate. The Kaplan-Meier survival curves showed that five years following therapy, the proportion of cases surviving with Bryne's scores lower or equal to 12 was 60.6% compared to only 17.6% for those with scores greater than 12. The drop in the survival curve of the patients with Bryne's scores greater than 12 was much steeper toward the end of the two years (nearly 16 months). In WHO Grades I and II, the survival rate was 48.9% and in Grade III, it was Nil.

The histologically invasive areas may be the only prognostic indicator for the clinical behavior of OSCC and can be used to predict overall survival in patients.