SCIENTIFIC LITERATURE

June 24, 2002

NCI Grant to Study Colorectal Cancer Metastasis

Using a $5-million National Cancer Institute grant, researchers at Jefferson Medical College and the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia are launching a clinical trial to determine whether a simple test for the protein that causes traveler's diarrhea can help surgeons and oncologists to better determine the extent of colorectal cancer in patients. In addition, the scientists hope that testing for guanylyl cyclase C (GCC) will help them to determine whether or not cancer has metastasized from the colon to the lymph nodes to improve diagnoses and give more appropriate treatment.

Scott Waldman, MD, PhD, Samuel M.V. Hamilton Family Professor of Medicine and director of the division of Clinical Pharmacology at Jefferson Medical College, is leading the research, which may result in a blood test that could tell patients whether colorectal cancer has returned. The test looks searches for GCC, which is expressed only by intestinal cells and colorectal cancer cells.

Patients typically undergo surgery to remove a tumor and the nearby lymph nodes, which are the first places to which cancer usually spreads. However, most pathologists examine only a thin slice of lymph node tissue-meaning that cancer may be missed. Further, this type of test lacks sensitivity, as it relies on a pathologist's ability to see colon cancer cells in a field of cells on a slide.

In this new method, a powerful amplification technique called reverse transcription polymerase chain reaction (RT-PCR) analysis magnifies the presence of malignant cells compared to normal cells and couples it with GCC, which may be a very specific marker for cancer. Amplification can find one malignant cell among 10-million cells. GCC appears to be very specific to colon cancer cells outside the intestine; it is expressed only in metastatic colon cancer cells that have spread to that region. By combining the marker with the amplification technique, researchers may have a very specific, sensitive way to find metastatic colon cancer cells in the lymph nodes of patients undergoing colorectal cancer staging.

The trial is recruiting about 2,000 patients at the Fox Chase Cancer Center in Philadelphia, the University of Florida in Gainesville, McGill University in Montreal, and Conemaugh Memorial Medical Center in Johnstown, PA. Scientists will examine RT-PCR-GCC analysis as a method to determine metastasis to the lymph nodes and then follow those patients for 5 years.

Patients who have a newly diagnosed colorectal cancer and be treated by a surgeon from one of the participating institutions are eligible for the trial. For more information, please call 1-800-JEFF-NOW.

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