Doctors find telltale cells in leukemia patients

By Gene Emery

BOSTON (Reuters) - Tell-tale cells may be able to warn people they are at risk of the most common type of leukemia, chronic lymphocytic leukemia, U.S. researchers reported on Wednesday.

They looked at frozen blood samples from 45 people later diagnosed with CLL and found cells called antibody-producing B cells circulating. People who have a certain type of these cells are diagnosed with a condition called monoclonal B-cell lymphocytosis.

CLL, which affects about 15,000 Americans each year and kills 4,500, is usually preceded by this condition, said Dr. Ola Landgren of the National Cancer Institute in Maryland.

The discovery could lead to better ways to treat and prevent the disease, the researchers said.

But the findings, reported in the New England Journal of Medicine, do not suggest that older people be routinely screened for B-cell clones, Landgren said.

That is because up to 5 percent of people over 50 have these cells in their blood but only a tiny fraction of them -- perhaps only 1 in 100 -- are destined to develop CLL that requires treatment.

"If people start to screen, it will lead to a lot of unnecessary anxiety, it will drive up the costs, and there is no therapy available," Landgren said in a telephone interview. "You cannot stop this from happening."

When he and his colleagues tested old blood samples collected earlier from 45 people who developed CLL, they discovered evidence of the cells in 44 of them, going as far back as six years.