Fig. 6

Cyclin E2 levels increase after progression on fulvestrant and correlate with clinical outcome. a Representation of cyclin E2 expression in samples from three patients with ER+ breast cancer before initiation of fulvestrant treatment (pre) and upon progress during treatment (post) as determined by immunohistochemical stainings. Quantifications of cyclin E2 scoring for each pre- and post- sample are shown to the left and representative stainings are shown to the right. b Evaluation of progression-free survival (PFS) in tumors with cyclin E2 low versus high expression in ER+ breast cancer patients treated with fulvestrant in the advanced setting. Kaplan-Meier plots for PFS are shown to the left and representative stainings for low and high cyclin E2 expression are shown to the right. p value represents log-rank test for PFS between patients with high and low levels of cyclin E2 expression. Scale-bar represents 25 μm in (a, b). c Cox multivariate regression analysis of PFS according to cyclin E2 expression levels, age at diagnosis of metastasis, and site of recurrence