In an amazing feat of scientific synchronicity, researchers in the U.S. and Canada have developed separate techniques to pinpoint elusive tumor cells from a thimbleful of drawn blood, a feat that may help predict the severity of a patient's cancer without biopsy or bone scan.
Both projects found that the greater the number of tumor cells collected in a sample, the more dangerous the disease appeared to be. The results are expected to give doctors a relatively painless tool to help identify who needs aggressive treatment, who is not benefiting from it and who might be spared the toxicity of chemotherapy.
But these early efforts are also driving long-term hopes that such a test might some day lead to a blood screening program that could catch cancer in its earliest stages.
Presently, researchers in Toronto are already testing the blood of women with a genetic risk of breast cancer who have no sign of the disease. They believe if this procedure can be applied to patients with early breast cancer, physicians can intervene early and have the potential to cure the disease or lengthen survival.
Although the technology is in its infancy, with researchers still searching for the significance of these cell counts in determining treatment and prognosis, Canadian physicians had already managed to detect tumor cells in the bloodstream of women even before their breast cancer appeared to have spread.
The U.S. effort focused on women with advanced breast cancer, in which the disease had already metastasized. U.S. scientists concluded women who had more than five tumor cells circulating in 7.5 millilitres of blood suffered a more virulent form of the disease and died sooner.
The detection of these cells, researchers said, can tell you about the progression of the disease. As a result, doctors may know more about what the prognosis will be, based on a simple blood test and new technology.
The Globe and Mail August 19, 2004