
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, May 6, 1993                   TAG: 9305060177
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-1   EDITION: METRO 
SOURCE: Associated Press
DATELINE: WASHINGTON                                LENGTH: Medium

GENE DEFECT DISCOVERED

Researchers have discovered a gene defect that identifies people with a 95 percent probability of developing an inherited form of colon cancer. The finding could lead to quicker diagnosis and save thousands of lives, they say.

"We have proven beyond any shadow of a doubt that a genetic predisposition for colon cancer exists," Dr. Bert Vogelstein, a Johns Hopkins University cancer researcher, said Wednesday. "We now can tell who will get it [the inherited form] and who will not."

Colon cancer kills 55,000 Americans annually, though the cure rate is 90 percent when detected in the early stages.

The researchers found that a mutated gene, carried by about one in every 200 people in the Western world, identifies people with an inherited and extraordinarily high risk of the disease.

"Patients who [have the mutation] will have a 95 percent chance of getting cancer," Vogelstein said Wednesday at a news conference organized by the journal Science.

The gene defect is thought to be responsible for about one in every seven colon cancer cases.

People most likely to have this gene, he said, are those with two or three close blood relatives who had colon or uterine cancer. There are an estimated five to 10 million Americans in such families, he said.

Such people, said Vogelstein, "should immediately go to their physician."

"We hope . . . to get people who have a strong family history to go to their doctor tomorrow and make their doctor aware," he said. Vogelstein advised such patients to tell their doctors, "I am at risk of colon cancer."

Scientists in the Hopkins lab of Vogelstein and in the lab of Dr. Albert de la Chapelle of the University of Helsinki located the gene defect on a segment of chromosome 2 of the human gene pattern. Reports by de la Chapelle, Vogelstein and a related study by Dr. Stephen Thibodeau of the Mayo Clinic in Rochester, Minn., are to be published Friday in the journal Science.

De la Chapelle said the cancer-causing mutation is located in such a small area of chromosome 2 that researchers using sophisticated genetic laboratory studies can now identify people with the gene flaw.

"Within six months to a year, we hope to be able to apply this test to affected families," he said. Once the defect is further identified, "it is conceivable that such a test can be applied to whole populations."

Such screening, said de la Chapelle, "could potentially prevent thousands of cancer deaths a year. It will give doctors the power to predict who will get the inherited form of this colon cancer."

by CNB