New Molecular Tests Detect Colorectal and Prostate Cancer

Colorectal cancer lymph node micrometastasis was detected using the guanylyl cyclase C (GCC) marker, and prostate cancer using the PCA3 marker.

GCC is expressed only in intestinal mucosal cells, but not in extra-intestinal tissues. In addition, GCC is expressed in colorectal tumors, but not in other cancers outside the gastrointestinal tract. Therefore, GCC may be useful clinically for the management of patients with colorectal cancer in providing information that is more accurate to physicians and patients and influencing treatment decisions.

A DiagnoCure (Québec, Canada) product, the Previstage GCC test was studied in 1,500 lymph nodes. The study demonstrated that in patients previously staged as having no positive lymph nodes (stage II), 30 % had at least one lymph node with GCC expression at least as high as that found in lymph nodes called positive by a pathologist (stage III). This would indicate that these patients should be considered for cancer management equal to that for a stage III patient.

The PCA3-based test, also developed by DiagnoCure, was used as a biomarker for prostate-cancer disease stratification.

The two DiagnoCure products, the PCA3 marker for prostate cancer and Previstage GCC for the staging of colorectal cancer, were presented at scientific meetings as part of the growing trend to molecular diagnostics. On June 4, 2008, DiagnoCure opened the sessions at the 34th annual International Clinical Ligand Assay Society Meeting held in Coral Springs (FL, USA), with a presentation on its guanylyl cyclase C (GCC) testing study.

At the meeting of the American Urological Association (AUA) in Orlando (FL,USA), which ended on June 4, 2008, the PCA3 marker-based test was the subject of several presentations and three exhibits. Gen-Probe, Inc. (San Diego, CA, USA), DiagnoCure's commercialization partner for PCA3, and other versions of the test by several different companies were also presented at the meeting.


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