The prognostic significance of circulating (CTC) and disseminated tumor cells (DTC) in patients with colorectal cancer (CRC) is controversial. We performed a meta−analysis of available studies to assess whether the detection of tumor cells in the blood and bone marrow of patients diagnosed with primary CRC can be used as a prognostic factor.

We searched the Medline, Biosis, Science Citation Index and Embase databases and reference lists of relevant articles (including review articles) for studies that assessed the prognostic relevance of tumor cell detection in the peripheral blood (PB), mesenteric/portal blood (MPB) or bone marrow (BM) of patients with CRC. Meta−analyses were carried out using a random effects model, with hazard ratio (HR) and 95% confidence intervals (95% CI) as effect measures.

A total of 36 studies including 3094 patients were eligible for final analyses. Pooled analyses that combined all sampling sites (PB, MPB, and BM) associated the detection of tumor cells with poor recurrence−free survival (RFS) (HR 3.24, 95% CI 2.06−5.10, n=26, I(2)=77%) and overall survival (OS) (2.28, 1.55−3.38, n=21, I(2)=66%). Stratification by sampling site revealed that detection of tumor cells in the PB compartment was a statistically significant prognostic factor (RFS: 3.06, 1.74−5.38, n=19, I(2)=78%; OS: 2.70, 1.74−4.20, n=16, I(2)=59%), but not in the MPB (RFS: 4.12, 1.01−16.83, n=8, I(2)=75%; OS: 4.80, 0.81−28.32, n=5, I(2)=82%) or in the BM (RFS: 2.17, 0.94−5.03, n=4, I(2)=78%; OS: 1.50, 0.52−4.32, n=3, I(2)=84%).

Detection of CTC in the peripheral blood indicates poor prognosis in patients with primary CRC. Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

PMID: 20100481 [PubMed − as supplied by publisher] Source: National Library of Medicine.