Experimental Test Finds Early Stages Of Colon Cancer
Associated Press
Thursday, January 31, 2002; Page A08
A new screening test appears able to find many colon cancer cases in their early, most curable stage by detecting extremely small traces of cancer genes in patients' stool.
The experimental test, still several years away from routine use, may offer an entirely new approach to mass screening for colon cancer, which will kill an estimated 48,000 Americans this year.
Doctors believe the test has the potential to be much more accurate than the current stool test, which checks for blood. That test can also detect the disease early, but it misses some cancers, and the ones it finds are outnumbered by false alarms.
The new test looks for a gene, known as the APC gene, that is usually faulty in the earliest stage of colon cancer. It finds the gene inside cancer cells that are sloughed off into the stool.
The test in its current form accurately found the bad gene in 57 percent of people with early cancer or precancerous growths, but it gave no mistakenly positive results in people who were cancer-free. Researchers say they can make the test 70 percent accurate and still avoid alarming false readings.
Bert Vogelstein and colleagues developed the test at the Johns Hopkins Kimmel Cancer Center in Baltimore. In tests on 74 people, the researchers found an average of four copies of the APC gene in every milligram of stool among those with cancer and two copies among those with precancerous growths, the researchers reported in today's issue of the New England Journal of Medicine.
That the researchers "found APC genes in all 74 stool samples they studied is a tour de force," journal editor Robert S. Schwartz said in an accompanying commentary. |
