Preoperative carcinoembryonic antigen level as an independent prognostic factor in colorectal cancer. Further comments.

Abstract

; the Editor: In the January issue of Jpn J Clin Oncol ,W ang et al. (1) found that preoperative carcinoembryonic antigen (CEA) levels are an independent prognostic factor in non-metastatic colorectal cancer patients after curative surgery. As the authors correctly pointed out, the prognostic significance of CEA is controversial in these patients. In order to explain the contradictory results that can be found in the biomedical literature, Wang et al. proposed various hypotheses. Among these, they indicated that the numerous studies that have been published so far may have used different analytical methods to measure CEA or, in other words, different CEA kits. Indeed, many published studies were performed over a very long period of time which coincided with important improvements in analytical methods. Immunoenzymatic methods and monoclonal antibodies have thus progressively replaced radioimmunoassays based on polyclonal antibodies, resulting in different specificities and