Prognostic relevance of three histological grading methods in breast cancer

Histological grading is an important parameter for the risk assessment in p atients with breast cancer. However, up to now differing grading methods ar e used which have not been compared with respect to their prognostic signif icance. In the present study the prognostic significance of three different methods of histological grading (Elston, Contesso, Helpap) was determined in a sample of 292 patients. Furthermore, results obtained in needle biopsi es were compared with those obtained in surgical resection specimens in 31 cases. The mitotic counts and the Contesso method were performed on two mic roscopes with different field areas (0.238 mm(2) and 0.345 mm(2)). Univaria te and multivariate analysis revealed that all three histological grading m ethods had a high prognostic value concerning overall survival (OS) and dis ease-free survival (DFS). Using univariate and multivariate analysis the El ston method performed best to determine OS and DFS (p <0.0001 and p <0.001) . The field area of the microscope had a minor influence on the mitotic cou nt and on the results of the Contesso method. The histological grading was reliable in needle biopsies: the best agreement to grading obtained in the definitive surgical specimen was achieved with the Elston method (kappa sta tistic 0.727). As a conclusion, we could show that determination of the his tological grade is an important prognostic factor in breast cancer with the Elston method giving the best results. Also, we could demonstrate that his tological grading in needle biopsies is reliable enough to allow a preopera tive risk estimation.