Of the 60,000 Americans who die from colon cancer each year, 5,000 to 10,000 carry a gene that predisposes them to the disease. With the recent announcement that scientists have now isolated that gene, there is a way to identify those people and help them take the kinds of precautions that could vastly prolong their lives.
Dr. Bert Vogelstein of the Johns Hopkins Oncology Center and )) Dr. Albert de la Chapelle, his collaborator in Helsinki, Finland, estimate that the gene could be carried by one of every 200 people, giving them a 95 percent chance of developing colon cancer.
That may seem like the kind of news most people would like tavoid. But there is a good chance of controlling colon cancer -- and a 90 percent chance of living at least another five years -- if it is caught early, before the tumor spreads.
The real value of this discovery is that it will help people do just that. Those who know they are virtually certain to develop the disease can take the appropriate steps to monitor their health. Those who do not carry the gene can "breathe a sigh of relief," in Dr. Vogelstein's words. However, since the people who carry this gene account for only one in seven of all cases of colon cancer, its absence does not indicate that a person is immune from this form of cancer.
The discovery will also enable scientists to do more productive research into the causes and prevention of cancer. For instance, by identifying people with a genetic predisposition toward colon cancer, researchers can more accurately test the value of studies suggesting that dietary factors or a daily aspirin might inhibit the disease.
There is another lesson here as well. Like every other medical advance, this news is good only for people who have access to health care. In a country where 35 to 37 million people have no health insurance, it is safe to assume that a good proportion of the people who carry this gene will not get the test that could discover it -- and, if even they did, would not have access to the careful monitoring that would make the knowledge a blessing rather than a curse. As scientists continue to produce discoveries of life-saving potential, the duty of policy makers to make it make these benefits accessible to everyone becomes even more urgent.