Blood Thinner May Reduce Cancer

Thursday, June 29th 2000, 12:00 am
By: News On 6

BOSTON (AP) — The common blood thinner warfarin may ward off cancer in people being treated for blood clots.

For reasons that are still a mystery, people who suffer clots in their legs or lungs run a substantially higher than usual risk of cancer.

A new study found that treatment with warfarin, also known as Coumadin, appears to cut this risk, though how it might do this is unknown.

Swedish doctors who conducted the study said their work ``strongly supports the impression'' that the drug has an anticancer effect, although they conceded that ``this idea will remain controversial in the absence of a demonstrated biochemical explanation.''

The study, directed by Dr. Sam Schulman of Karolinska Hospital in Stockholm, was published in Thursday's New England Journal of Medicine.

The research involved 854 patients who had suffered either deep-vein thrombosis in a leg or a pulmonary embolism, a clot that blocks an artery that supplies the lungs. Half got warfarin for six weeks, the rest for six months.

During six years of follow-up, cancer was diagnosed in 16 percent of the patients who received warfarin for six weeks and in 10 percent of those who got the drug for six months. The biggest reduction was in cancer of the kidney, bladder, prostate, ovaries and uterus.

A Veterans Administration study in the early 1980s looked at the same question but reached less sweeping conclusions. It found that warfarin seemed to improve survival in people with small-cell lung cancer but not other kinds of malignancy.

An editorial in the journal, written by Drs. Christoph C. Zielinski and Michael Hejna of University Hospital in Vienna, said warfarin's potential is worth further study. But it cautioned against offering the medicine yet as a way to prevent cancer.