Abstract 4547: Clinical relevance of circulating tumor cells in esophageal cancer

Abstract

Abstract Background: Current modalities to predict tumor recurrence and survival in esophageal cancer are insufficient. Locoregional and distant relapse is even common in lymph node-negative patients and more precise staging methods are therefore needed. Little is known about the utility of circulating tumor cells (CTC) as staging tool in esophageal cancer. Methods: In a prospective study we identified CTC in peripheral blood of esophageal cancer patients by two separate methods. We enrolled 85 consecutive esophageal cancer patients (03/2010-10/2011) who were surgically resected (R0) and patients received neither neoadjuvant nor adjuvant therapy. Peripheral blood was taken at the time of primary surgery and CTC were detected by either manual MACS enrichment (anti-cytokeratin plus anti-EpCam) with subsequent anti-cytokeratin staining or the automated CellSearch system (cleared by the FDA for CTC detection in metastatic breast, colon and prostate cancer) in parallel. CTC detection rates and correlation with clinicopathologic parameters were evaluated. The median clinical follow-up time is 11 months ranging from 1 to 19 months. Results: So far, 67 patients have been analysed of which 21 (31.3%) had CTCs using MACS, and 10 (14.9%) using CellSearch. CTCs detected with MACS significantly correlated with tumor size (p=0.040) and aggressive tumor biology as indicated by presence of regional lymph node (p=0.040) and distant metastases (p=0.019). CTCs detected with CellSearch correlated significantly with lymph node (p=0.044) and distant metastases (p=0.045), while no correlation was observed for tumor size or grading. CTC-positive patients had a worse overall survival than CTC-negative patients when tested with the CellSearch system (p=0.009). Conclusion: The presence of CTCs in patients with resectable esophageal cancer correlates with clinicopathologic risk factors.and predicts an unfavorable prognosis. Thus, our pilot study suggests that CTC detection may contribute to an improved staging in esophageal cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4547. doi:1538-7445.AM2012-4547