Bryne's grading system predicts poor disease-specific survival of oral squamous cell carcinoma: a comparative study among different histologic grading systems

Abstract

The aim of this study was to access the prognostic value of 4 histopathologic grading systems of oral squamous cell carcinoma (OSCC): The World Health Organization (WHO), Anneroth, Bryne (1989), and Bryne (1992). Eighty-five cases of OSCC diagnosed between 1996 and 2010 at the Clinics Hospital of Porto Alegre (Porto Alegre, Brazil) were included. Slides stained with hematoxylin and eosin were obtained, and a histologic grade was assigned on the basis of the consensus of 3 expert oral pathologists, who were blinded to the clinicopathologic factors. Each system was correlated with proliferative labeling index, accessed through Ki67 immunostaining, clinicopathologic factors, patient outcome (alive or deceased), and survival time. The increase in Bryne (1992) histologic grades was accompanied by an increase in proliferative labeling index. Moreover, this system was the only one associated with patient outcome (P=.01) and survival. Bryne (1992) grading system grade III tumors were associated with poor disease-specific survival according to univariate and multivariate cox regression analyses and the log-rank test (P<.05). The other systems evaluated presented no association with patients' outcome or survival. The Bryne (1992) grading system is more effective in predicting survival in OSCC compared with the systems proposed by the WHO, Anneroth, or Bryne (1989).