In addition, Ki67 expression < 40% was a marker for favorable DFS rates, which is in agreement with a previous study in which patients with Ki-67 values > 45 % had reduced DFS.38 A limitation of our study was the relatively short follow-up period of 3 to 56 months (median 29 months), which did not cover the different recurrence patterns of the breast cancer molecular subtypes, and that our study was retrospective. This evidence concerns the gene MKI67 and breast carcinoma.