Ecancermedicalscience is the peer-reviewed open access cancer journal founded by the European Institute of Oncology in Milan. We consider articles on all aspects of research relating to cancer, including molecular biology, genetics, pathophysiology, epide

To determine whether functional proteomics improves breast cancer classification and prognostication and can predict pathological complete response (pCR) in patients receiving neoadjuvant taxane and anthracycline-taxane-based systemic therapy (NST). Reverse phase protein array (RPPA) using 146 antibodies to proteins relevant to breast cancer was applied to three independent tumor sets. Supervised clustering to identify subgroups and prognosis in surgical excision specimens from a training set (n = 712) was validated on a test set (n = 168) in two cohorts of patients with primary breast cancer. A score was constructed using ordinal logistic regression to quantify the probability of recurrence in the training set and tested in the test set. The score was then evaluated on 132 FNA biopsies of patients treated with NST to determine ability to predict pCR. Six breast cancer subgroups were identified by a 10-protein biomarker panel in the 712 tumor training set. They were associated with different recurrence-free survival (RFS) (log-rank p = 8.8 E-10). The structure and ability of the six subgroups to predict RFS was confirmed in the test set (log-rank p = 0.0013). A prognosis score constructed using the 10 proteins in the training set was associated with RFS in both training and test sets (p = 3.2E-13, for test set). There was a significant association between the prognostic score and likelihood of pCR to NST in the FNA set (p = 0.0021). We developed a 10-protein biomarker panel that classifies breast cancer into prognostic groups that may have potential utility in the management of patients who receive anthracycline-taxane-based NST.

Ovarian cancer is now recognized as a number of distinct diseases primarily defined by histological subtype. Both clear cell ovarian carcinomas (CCC) and ovarian endometrioid carcinomas (EC) may arise from endometriosis and frequently harbor mutations in the ARID1A tumor suppressor gene. We studied the influence of histological subtype on protein expression with reverse phase protein array (RPPA) and assessed proteomic changes associated with ARID1A mutation/BAF250a expression in EC and CCC.

Purpose: Using reverse phase protein array, we measured protein expression associated with response to primary chemotherapy in patients with advanced-stage, high-grade serous ovarian cancer. Experimental Design: Tumor samples were obtained from 45 patients with advanced high-grade serous cancers from the Gynecology Tumor Bank at the British Columbia Cancer Agency. Treatment consisted of platinum-based chemotherapy following debulking surgery. Protein lysates were prepared from fresh frozen tumor samples, and 80 validated proteins from signaling pathways implicated in ovarian carcinogenesis were measured by reverse phase protein array. Normalization of Ca-125 by the 3rd cycle of chemotherapy was chosen as the primary outcome measure of chemotherapy response. Logistic regression was used for multivariate analysis to identify protein predictors of Ca-125 normalization and Cox regression to test for the association between protein expression and progression-free survival. A significance level of P ≤ 0.05 was used. Results: The mean age at diagnosis was 56.8 years. epidermal growth factor receptor, YKL-40, and several transforming growth factor β (TGF-β) pathway proteins [c-jun–NH₂–kinase (JNK), JNK phosphorylated at residues 183 and 185, plasminogen activator inhibitor 1, Smad3, TAZ] showed significant associations with Ca-125 normalization on univariate testing. On multivariate analysis, epidermal growth factor receptor (P < 0.02), JNK (P < 0.01), and Smad3 (P < 0.04) were significantly associated with normalization of Ca-125. Contingency table analysis of pathway-classified proteins revealed that the selection of TGF-β pathway proteins was unlikely because of false discovery (P < 0.007; Bonferroni adjusted). Conclusion: TGF-β pathway signaling likely plays an important role as a marker or mediator of chemoresistance in advanced serous ovarian cancer. On this basis, future studies to develop and validate a useful predictor of treatment failure are warranted. Clin Cancer Res; 16(10); 2852–60. ©2010 AACR.