Cancer Detected Earlier and Faster with New Imaging Technology

Dr. Contag reported that he hoped it might be one of the first to be used routinely for early detection of cancer.

"Detecting colon cancers is just the first step,” said Dr. Contag. He predicted similar techniques would eventually be able to find a wide range of cancers, monitor cancer treatment, and deliver chemotherapies directly to cancerous cells in the colon, stomach, mouth, and skin. The study was published online March 16, 2008, issue of the journal Nature Medicine.

Colon cancer is the third most common cancer in men and women, with approximately 150,000 people diagnosed each year in the United States. Although colonoscopy is not perfect, it is currently the best way of finding colon cancers when they are still at the most treatable stage.

The trick to detecting cancer without a biopsy is to find a way of seeing which cells are cancerous while they are still in the body. That is what Dr. Contag and his group succeeded in doing. The group found a short protein that adheres to colon cells in the early stages of cancer. Before screening a person, they spray that short protein attached to a fluorescent beacon into the colon. The protein then attaches to any cancerous cells and creates an easily visible fluorescent patch.

Not only did the researchers see fluorescent patches, they could make out the individual cancerous cells. That fine resolution could allow clinicians to identify the earliest possible tumors. According to Dr. Contag, it could also become a useful research tool for studying the small number of cancer stem cells that are thought to establish the eventual tumor.

In the initial trial with 15 patients, the technique detected 82% of the polyps that were considered cancerous by a pathologist. Dr. Contag reported that the next step is to work with some of the additional small proteins they have found that also attach to cancerous cells. He thinks that a combination of those proteins will make the technique highly accurate.

Once the screen is ready for widespread use, it could bring effective cancer detection to people in remote locations who otherwise do not have access to pathology labs. "A doctor could send a video in real time via the Internet to someone trained to analyze the living cell images,” Dr. Contag said. This could help people begin the appropriate therapy when the cancer is still at an early stage.

Dr. Contag believes this technique, developed in part through the cancer-imaging program at the Stanford Cancer Center, could also be adapted to detect cancers in the mouth, esophagus, and the stomach. Moreover, real-time screening could be used as a way of assessing whether a chemotherapy regimen is working.


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Stanford University School of Medicine