Laser technology may soon make it possible for patients to forego painful surgical biopsies. In recent tests at Dartmouth College in Hanover, New Hampshire, physicist Mary-Ann Mycek illuminated cells from colon polyps with a violet-blue laser. When cells are targeted briefly with a bright beam of light their molecules absorb energy, then emit it in a different color, an effect called fluorescence. In this case, Myeck found that cells exhibiting epithelial dysplasia, a condition that usually leads to colon cancer, fluoresced more quickly and more faintly than the healthy ones. "We don't understand the biophysics behind this," she says. "It just works."
The process identified epithelial dysplasia with a 92 percent accuracy rate, 5 percent more reliably than pathologists can identify the disease after biopsy. Best of all, results of a laser exam are available instantly, which can save a patient from a lot of worry. Mycek hopes such cancer detection equipment will be in the hands of doctors by early next year.
