“…Most of the available data related to the CEA mRNA detection indicate that the presence of circulating tumor cells correlates with the presence of distant metastasis (Funaki et al, 1996;Mori et al, 1996;Jonas et al, 1996;Mori et al, 1998;Castells et al, 1998) and is expected to be associated with a poor prognosis (Hardingham et al, 1995;Mori et al, 1998). But it is still uncertain of its clinical relevance, because a relatively high proportion of non-metastatic gastrointestinal cancer patients was also positive for CEA mRNA (Mori et al, 1996;Mori et al, 1998;Castells et al, 1998).…”