Aspirin may be able to "starve" out colon cancer in much the same way as highly publicized experimental drugs cut off the blood supply to tumors in mice, researchers say.

The findings, by a team at Vanderbilt University in Nashville, Tenn., could explain some studies that indicate people who take aspirin every day may be protected, to some degree, from colon cancer.Writing Thursday in the journal Cell, Dr. Raymond DuBois and colleagues at Vanderbilt said the basic action of aspirin could be targeting the ability of colon cancer tumors to create a blood supply for themselves.

On a very basic level, aspirin interferes with the production of enzymes known as cyclooxygenases, COX for short. There are two types, COX-1 and COX-2. Other, related drugs, known as non-steroidal anti-inflammatory drugs or NSAIDS, have the same method of action.

Among other things, COX-2 is responsible for inflammation, while COX-1 is widespread in all cells. COX-2 is known to be elevated in colon cancer cells.

DuBois' team grew colon cancer cells in a dish and found the cells that produced COX-2 started the process of growing little blood vessels. This process is known as angiogenesis.

Drugs that interfere with angiogenesis have received a great deal of attention lately, because of work by Dr. Judah Folkman and colleagues at Boston Children's Hospital. Some of the drugs have been found to stop the growth of tumors in mice.