Detecting malignant tumors earlier.

Earlier detection of malignant tumors may be possible with a new method developed by University of Texas Southwestern Medical Center at Dallas researchers that identifies cancer cells in blood. The scientists found that patients with breast and prostate cancer had significantly more epithelial cancer cells in their blood than people who are disease free, notes Jonathan Uhr, professor of microbiology and internal medicine, the lead author of the study. "The major potential use of this test would be to detect early tumors. It's an extremely sensitive test. It can detect one cancerous epithelial cell in a milliliter of blood."

To identify the cells in the blood of cancer patients, the investigators treated blood samples with an antibody-coated iron particle to search for the cancer cells and then used a laser to turn malignant cells a different color than the rest of the sample. This allowed researchers to pick out cells with tumor characteristics. They confirmed findings by microscopic examination.

"Our major goal now is to fine-tune and automate the test before using it in high-risk patient groups to determine if we can pick up shedding of malignant cells from the primary tumor at a very early stage--possibly before detection of the primary tumor in some patients," Uhr indicates.

In all 12 breast-cancer patients in the study, there was a positive correlation between the number of tumor cells in the blood and the clinical status. When the...