ICER of removing all diminutive polyps was $465,407/LYG, and small CTC-detected polyps $59,015 per LYG.
Considering CTCs undergoing epithelial-mesenchymal transition (EMT) are smaller in size [13], and many small CTCs are clinically relevant [9, 14], inherent limitation of cell filtration technique on detection of highly heterogeneous populations of CTC and DTC should not be ignored.
However, recent studies demonstrated the existence of plenty of CTCs and DTCs with the size either similar or smaller than that of WBCs in both patients [6 8] or patient derived xenograft (PDX) tumor animal models [7, 9], suggesting that cell size-based filtration may lose significant amount of small CTCs and DTCs [10 12].
Nevertheless, concerns regarding missing small CTCs have been raised.
Microfluidic chips and filters that fractionate by size will not capture small CTCs.
CellSearch detected low CTC numbers in pancreatic cancer patients in comparison with other epithelial carcinomas such as breast, prostate, colorectal and small cell lung cancer (Cristofanilli et al, 2004; Cohen et al, 2008; de Bono et al, 2008; Hou et al, 2009) Two previous studies of pancreatic cancer CTCs using CellSearch reported low CTC numbers in agreement with our data.
However, some men have low CTCs despite widespread disease, suggesting heterogeneity in CTC phenotype or detection.
However, the small number of CTC reduces this complexity and could possibly provide a better picture for individualised treatments.
We show that large CTCs and CTC clusters can successfully cross capillaries if their stiffness is relatively small.
However, the small numbers of CTCs and the limited access to bone marrow aspirates in cancer patients pose major hurdles.
However, it appears that only a small proportion of CTCs are capable of forming overt tumor deposits [ 13].
