The value of proliferation indexes in breast cancer

During the past several years, the Ki-67 antigen has gathered great interest in its role as a prognostic marker. Nevertheless, despite the large number of published papers, the role of Ki-67 in clinical practice remains controversial.

To evaluate the association between Ki-67 immunoreactivity and other clinicohistopathological parameters.

We retrospectively analyzed the archival pathology tissues of 356 patients, diagnosed and treated in our department, from 2002 to 2006. Statistical analysis was used to examine the association between Ki-67 expression and other clinicopathological factors.

The expression of Ki-67 was correlated with the mitotic count, tumor grade and size and p53, HER2 and EGFR expression. Furthermore Ki-67 expression was significantly related with nodal status and inversely associated with hormonal expression. Moreover, invasive carcinomas appeared to have greater proliferation values than in situ carcinomas, while invasive ductal carcinomas were correlated with higher Ki-67 expression compared to lobular cancers.

The expression of Ki-67 appears to be a valuable method of proliferation measurement that could prove helpful in clinical practice. Further research is warranted in order to standardize the methodology and to reach uniformity in regard with the optimal cut-off value.