Identification of mRNA markers for molecular staging of lymph nodes in colorectal cancer.

BACKGROUND One evolving approach to improved prognostication of cancer patients is the identification of previously occult disease by use of quantitative reverse transcription-PCR. Surprisingly, no systematic analysis of potential mRNA markers for colorectal cancer has been reported. We therefore performed an extensive mRNA marker survey for colorectal cancers. METHODS We identified potential markers through literature and database searches. We analyzed all markers by quantitative reverse transcription-PCR on a limited set of primary tumors and benign lymph nodes. Selected markers were further evaluated on a larger tissue set with positive lymph nodes. RESULTS We evaluated 43 markers and undertook further analysis of 6 in the secondary screening. Five gene markers--CDX1, carcinoembryonic antigen (CEA), CK20, TACSTD1, and Villin1 (VIL1)--provided perfect classification of lymph node status. CONCLUSIONS Several mRNA markers are capable of providing exceptionally accurate characterization of lymph node status in colorectal cancer. An automated, multimarker, quantitative reverse transcription-PCR assay for characterization of lymph nodes from colorectal cancer patients may be useful for improved staging and therapeutic decision making in colorectal cancer.