Guanylyl Cyclase C (GCC or GUCY2C) Marker for Colorectal Cancer
DiagnoCure owns the exclusive worldwide diagnostic rights to the Guanylyl Cyclase C (GCC or GUCY2C) marker and its applications to colorectal cancer. In September 2008, the Company launched its proprietary Previstage™ GCC, Colorectal Cancer Staging Test. GCC is a gene coding for a protein found in cells, both normal and cancerous, lining the intestine from the duodenum to the rectum. It is involved in multiple functions, including water transport, crypt morphology and suppression of tumorigenesis. It is not normally found in tissue in other parts of the body. When GCC is detected outside of the intestine, it is an indication of the presence of colorectal cancer metastases.
Dr. Scott Waldman, at Thomas Jefferson University, first identified the relation between GCC and colorectal cancer in the early 1990s. GCC mRNA has shown to be highly accurate in detecting the spread and recurrence of colorectal cancer, respectively in lymph nodes and blood, thereby representing a significant improvement over traditional detection methods. To date, over 50 peer-reviewed journal articles have discussed the relationship between GCC mRNA and colorectal cancer (visit our Scientific Publications page for a listing). In particular, results of studies on the GCC mRNA, totaling over 1,000 patients, have been published. Below is a summary of the most recent ones:
Initial studies
The U.S. National Institutes of Health (NIH) provided two grants amounting to over $10 million to Dr.Waldman for two prospective five-year multicenter studies of the GCC marker as it relates to its potential clinical uses in colorectal cancer.The first study, on GCC testing of lymph nodes to better determine risk of recurrence, was completed and published in the peer-reviewed Journal of the American Medical Association (Feb.18, 2009, Vol.301, No.7). The study was performed with over 400 enrolled CRC patients from nine different sites. The results strongly demonstrated that testing of lymph nodes for GCC can more accurately predict the risk of stage I and II colorectal cancer (CRC) patients having disease recurrence.
In a group of 257 stageI and II CRC patients, when GCC was considered with other factors, patients whose nodes were GCC positive were 4.7 times more likely to develop disease recurrence than those whose nodes were GCC negative, and 3.3 times more likely to die within three years. In fact, patients with GCC positive nodes had a risk of recurrence and survival rate comparable to that of stage III CRC patients.
The second study sponsored by the NIH is evaluating whether detection of GCC in the blood can identify earlier recurrences of colorectal cancer.
GCC as a prognostic marker of disease recurrence
In January 2010, at the Gastrointestinal Cancers Symposium of the American Society of Clinical Oncology (ASCO GI), DiagnoCure presented the results of a study on the GCC marker used in its PrevistageTMGCC test. The study analyzed the results of the GCC molecular test on lymph nodes of 123 patients that were considered having stage II cancer by standard pathology assessment. It demonstrated that patients who had at least one GCC positive lymph node were two times more likely to experience recurrence of their cancer than patients who had no GCC positive lymph nodes. The study was also published in the Journal of Clinical Pathology (2010, vol 63, 530-577).