Little is known about signaling pathway activity in esophageal adenocarcinomas. Using a new methodology we have delineated the activity of key pathways involved in tumor growth during neoadjuvant treatment. The aim is to use this knowledge to personalize, and thereby improve, treatment strategies.
We included all patients with esophageal adenocarcinomas between 2004 and May 2013 in the AMC. Paired tumor samples were obtained before start of neoadjuvant chemoradiation therapy according to the CROSS regimen and at surgical resection of the esophagus. Using a custom-built device, digital annotations of whole slide H&E scans were transferred to a hematoxylin-stained slide, which was subsequently deparaffinized. Marked tumor areas were scraped for RNA extraction and qPCR. qPCR data were subjected to stringent QC prior to determining the signaling pathway activity scores of the AR-, ER-, FOXO/PI3K-, HH-, TGF-β- and WNT pathway, using a combined mRNA-Bayesian model-based method (Verhaegh et al, Cancer Res, 2014). Pathway activity scores were correlated to pathological response to treatment (Mandard score).
Based on a test set of esophageal tumor tissue samples, we determined that tumor areas of ≥ 2mm2 were eligible for RNA isolation and pathway activity analysis. We provide a analysis of 288 currently processed samples. FOXO activity was significantly higher in post-treatment resection specimen compared to matched pre-treatment biopsies (p < 0.001). Patients with high FOXO activity in post-treatment resection specimen showed better response to treatment (p = 0.019).
The assessment of pathway activity is feasible on small amounts of tumor. Marked dynamics in FOXO activity are observed during nCRT in esophageal adenocarcinomas. Patients with high FOXO activity post-nCRT show better response to treatment. An active PI3K pathway blocks FOXO transcriptional activity. To increase FOXO transcriptional activity, patients might benefit from the addition of PI3K-inhibitors to the nCRT regimen.
Clinical trial identification
Legal entity responsible for the study
M. Stoffels, L. Holtzer, A. Van Brussel: Employee: Royal Philips; Research funding: Royal Philips. H. van Ooijen: Employee: Royal Philips; Patents, royalties or other intellectual property: Royal Philips. E.M.G. Aussems-Custers. A. van de Stolpe: Employee, Funded: Royal Philips. M. van Berge Henegouwen: Research funding: Olympus. M.F. Bijlsma: Research funding: Celgene. H.W.M. van Laarhoven: Consultant: Philips, Celgene, Lilly, Nordic; Unrestricted research funding: Philips, Bayer, BMS, Celgene, Lilly, Merck Serono, MSD, Nordic, Roche. All other authors have declared no conflicts of interest.