METHOD FOR DETECTING METASTASIS OF GI CANCER

The present invention provides a novel method for diagnosing, prognosing and staging Lymph Node (LN) status in colorectal cancer (CRC) that is more sensitive and accurate than conventional detection technologies such as histopathology. The Guanylyl Cyclase C (GCC) gene is specifically expressed in apical epithelial cells of the GI tract from the duodenum to the rectum and the detection of GCC mRNA in LNs is indicative of the presence of metastases. Quantitative RT-PCR (RT-qPCR) detection of GCC mRNA to identify the presence of colorectal cancer (CRC) cells in LNs has the potential to aid in CRC staging. When used in combination with glucuronidase B (GUSB), accurate quantification of GCC can be achieved with less than a 2-fold variation between intact and highly degraded RNA specimens. The invention also relates to a newly designed GCC/GUSB assay that uses relative quantification having improved prognostic value for time to recurrence and relapse-free survival in Stage I and II colon cancer patients. The GCC/GUSB assay also improves the statistical power of prognosis stratification for relative risk of recurrence and relapse-free survival.