BOSTON, Dec. 19 -- An experimental lab-on-a-chip can accurately
detect cancer cells circulating in the blood, researchers here
said. The chip -- slightly more than 1.5 square inches in area
-- detected circulating cancer cells in 115 of 116 blood samples
from patients with metastatic cancer for a sensitivity of 99.1%,
according to Daniel Haber, M.D., director of the Massachusetts
General Hospital Cancer Center, and colleagues. And it found no
cancer cells in the blood of healthy volunteers, for a
specificity of 100%, the researchers reported in the Dec. 20
issue of Nature. "Clearly this has tremendous potential for
early diagnosis," Dr. Haber said, but it also has the potential
to allow physicians to monitor the success or failure of
treatment more closely and to begin to solve some of the puzzles
that surround metastasis. Circulating tumor cells are found in
patients even before a cancer has begun to spread, but they are
rare -- as few as one in a billion hematologic cells even in the
metastatic case -- and