Evaluation of prognostic significance of circulating tumor cells detection in rectal cancer patients treated with preoperative radiotherapy: prospectively collected material data.

Dominika Nesteruk,Jacek Pawlak,Janusz A Siedlecki,Anna Fabisiewicz,Andrzej Rutkowski,Stanisław Fabisiewicz

doi:10.1155/2014/712827

Abstract

The aim of this study was to evaluate the prognostic value of circulating tumor cells (CTC) in nonmetastatic rectal cancer patients treated with short-term preoperative radiotherapy. In this single-center trial, 162 patients with rectal cancer after preoperative short-term radiotherapy (5 × 5 Gy) were recruited from January, 2008 to September, 2011. Clearance of CTC was determined in 91 patients enrolled in the molecular analysis. CTC presence was evaluated with real-time reverse transcription polymerase chain reaction assay (qPCR) based on the expression of three tumor genetic markers: carcinoembryonic antigen (CEA), cytokeratin 20 (CK20), and/or cancer stem cells marker CD133 (CEA/CK20/CD133). We found that CTC detection 7 days after surgery was of prognostic significance for the local recurrence (P value = 0.006). CTC detected preoperatively and 24 hours after resection had no prognostic value in cancer recurrence; however, there was a significant relationship between CTC prevalence 24 hours after surgery and lymph node metastasis (pN1-2). We also confirmed a significant clearance of CTC in peripheral blood (PB) 24 hours after surgery. Preoperative sampling is not significant for prognosis in rectal cancer patients treated with short-term radiotherapy. Detection of CTC in PB 7 days after surgery is an independent factor predicting local recurrence in this group of patients.

Highlights

Circulating tumor cells (CTC) can be detected in peripheral blood (PB) of cancer patients who have no evidence of overt metastases [1, 2]
The aim of this study was to clarify the prognostic significance of CTC presence in PB after resection of nonmetastatic rectal cancer in patients treated with preoperative radiotherapy
No significant differences in the CTC presence were observed between patients who received gentamicin collagen implant (GCI) implant and patients in the control group in either of the blood sampling; all patients were analyzed as one group

Summary

Introduction

Circulating tumor cells (CTC) can be detected in peripheral blood (PB) of cancer patients who have no evidence of overt metastases [1, 2]. Dissemination of tumor cells is thought to occur early on in the cancer development. The presence of CTC in PB has proven to be of prognostic significance in patients with metastatic colorectal cancer [3, 4]. Clinical significance of CTC is being investigated. The review by Peach et al [6] summarized that the presence of CTC in PB at least 24 h after tumor resection was an independent prognostic marker of recurrence, but there was no significant correlation between CTC and survival perioperatively. Significant differences in CTC detection rates in nonmetastatic cancer patients were observed [7] and the presence of CTC in nonmetastatic colon cancer was barely detectable with the CellSearch System—the only system approved for clinical routine use [8]

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Conclusion