High protein expression of EZH2 is related to unfavorable outcome to tamoxifen in metastatic breast cancer.

BACKGROUND: Metastatic breast cancer (MBC) is a highly heterogeneous disease with great differences in outcome to both chemo- and endocrine therapy. Better insight into the mechanisms underlying resistance is essential to better predict outcome to therapy and to obtain a more tailored treatment approach. We have previously described that increased mRNA expression levels of Enhancer of Zeste homolog (EZH2) are associated with worse outcome to tamoxifen therapy in MBC. Here, we explored whether this is also the case for EZH2 protein expression. PATIENTS AND METHODS: A tissue microarray (TMA) was created using formalin-fixed, paraffin-embedded estrogen receptor (ER)-positive primary breast tumor tissues of 250 MBC patients treated with first-line tamoxifen. Quantity and intensity of EZH2 expression were determined by immunohistochemistry (IHC) and both were used to generate and group scores according to a previously described method for scoring EZH2. RESULTS: In total, 116 tumors (46%) were considered to be EZH2 positive. The presence of EZH2 protein expression was significantly associated with progression-free survival (PFS) in both univariate [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.17-1.97, P = 0.002] and multivariate analysis including traditional factors associated with tamoxifen outcome (HR 1.41, 95% CI 1.06-1.88, P = 0.017). Considering quantity irrespective of intensity, tumors with >50% EZH2-positive cells had the worst PFS (HR 2.15, 95% CI 1.42-3.27, P < 0.001), whereas intensity alone did not show a significant association with PFS. Application of other methods of scoring EZH2 positivity resulted in a similar significant association between the amount of EZH2 positive cells and PFS. CONCLUSION: In addition to EZH2 mRNA levels, these results suggest that protein expression of EZH2 can be used as a marker to predict outcome to tamoxifen therapy. This provides new rationale to explore EZH2 inhibition in the clinical setting and increases the possibilities for a more personalized treatment approach in MBC patients.

Genomic aberrations relate early and advanced stage ovarian cancer.

BACKGROUND: Because of the distinct clinical presentation of early and advanced stage ovarian cancer, we aim to clarify whether these disease entities are solely separated by time of diagnosis or whether they arise from distinct molecular events. METHODS: Sixteen early and sixteen advanced stage ovarian carcinomas, matched for histological subtype and differentiation grade, were included. Genomic aberrations were compared for each early and advanced stage ovarian cancer by array comparative genomic hybridization. To study how the aberrations correlate to the clinical characteristics of the tumors we clustered tumors based on the genomic aberrations. RESULTS: The genomic aberration patterns in advanced stage cancer equalled those in early stage, but were more frequent in advanced stage (p = 0.012). Unsupervised clustering based on genomic aberrations yielded two clusters that significantly discriminated early from advanced stage (p = 0.001), and that did differ significantly in survival (p = 0.002). These clusters however did give a more accurate prognosis than histological subtype or differentiation grade. CONCLUSION: This study indicates that advanced stage ovarian cancer either progresses from early stage or from a common precursor lesion but that they do not arise from distinct carcinogenic molecular events. Furthermore, we show that array comparative genomic hybridization has the potential to identify clinically distinct patients.

Dose-dense therapy is of benefit in primary treatment of ovarian cancer: contra.

Several studies in the past have tried to improve the prognosis of ovarian cancer by increasing the dose intensity of platinum. Only 2 out of 12 randomized studies showed survival benefit at the cost of significant long-term toxicity. Dose-dense induction therapy with combined weekly paclitaxel (at a dose of 90 mg/m(2)) and weekly carboplatin [at an area under the curve (AUC) of 4 mg·ml/min] followed by 3-weekly paclitaxel/carboplatin was very effective in platinum-resistant patients (response 58%, progression-free survival 10 months). In first-line, however, no survival benefit was found with the same dose-dense weekly paclitaxel/carboplatin regimen over standard-dosed 3-weekly paclitaxel/carboplatin in a randomized study. Very recently, the Japanese Gynecologic Oncology Group (JGOG) study no. 3016, randomizing patients in first-line between dose-dense weekly paclitaxel 80 mg/m(2) plus 3-weekly carboplatin AUC 6 and 3-weekly paclitaxel/carboplatin, showed a significant increase in progression-free survival (median 28 versus 17.2 months in the control arm; hazard ratio for progression, 0.71; 95% confidence interval, 0.58-0.88; P=0.0015). The 3-year overall survival was 72% versus 65% (P=0.03), respectively. The hematologic toxicity was substantial in both arms and substantially higher than observed with the weekly paclitaxel/carboplatin induction regimen. Many patients had treatment delays, dose reductions and stopped treatment prematurely. The JGOG 3016 study is the only dose-dense study with such a significant survival benefit. It is also the only dose-intensity study performed in Asian patients. Genotypes and phenotypes are thought to represent important determinants of drug efficacy in ovarian cancer. Therefore, confirmatory studies with this JGOG regimen together with translational research are needed in both Caucasian and Asian patients.