Circulating tumor cells as a possible prognostic tool in newly diagnosed nonmetastatic colorectal cancer?

Abstract

395 Background: The presence of circulating tumor cells (CTC) is associated with poor prognosis in patients with metastatic colorectal cancer (CRC). The current study was conducted to determine if the presence of CTC prior to surgery in patients with newly diagnosed non-metastatic CRC can identify those patients at risk for disease recurrence. Methods: In a prospective single center study 180 patients with newly diagnosed non-disseminated CRC scheduled for surgery were enrolled and followed up for a median of 41 months. CTC were enumerated with the CellSearch System in 4 aliquots of 7.5 ml of peripheral blood before undergoing surgery. The control group consisted of sixty patients with benign tumors after surgery or colonoscopy. Results: ≥1 CTC/ 30ml of blood were detected in 9 (15%) persons of the control group, and in 41 (23%) CRC patients. From the 180 CRC patients, 44 developed recurrent disease (24%) and 38 patients (21%) died during follow up. Presence of CTC correlated with disease recurrence (p= 0.040) and death (p=0.006). Patients with CTC had a significantly decreased three year Disease Free Survival (DFS) and overall survival (OS) versus those without CTC (DFS 57%vs. 78%, p=0.018 and OS 70% vs. 80%, p=0.003%). Conclusions: Patients with stage I-III CRC with CTC before surgery have a significantly lower 3 years DFS and OS. These findings warrant further development of technology to increased the sensitivity and specificity of CTC detection for incorporation as prognostic marker along side Duke Stage to assess which patients need adjuvant treatment.