BOSTON — A new blood test appears to accurately detect all forms of cancer and may someday provide the first simple means of routinely screening people for the disease, doctors say.
Working with only small samples of blood, researchers were able to distinguish cancer victims from people who were healthy or had a variety of other diseases.
"Our accuracy is well over 90%," said the test's developer, Dr. Eric T. Fossel of Boston's Beth Israel Hospital. "It's much higher than any other blood test."
Fossel said the test might someday become part of a routine physical exam. But he said studies first will be necessary on large numbers of people to learn whether the test will reveal cancer in its earliest and most treatable stages.
Major Quest of Medicine
A test that will reveal minuscule cancerous lumps before they can be felt or show up on X-rays is a major quest of medicine, but until now it has eluded scientists. Some tests will disclose substances that spill out of tumors, but none of these secretions is present in all kinds of cancer or clearly differentiates healthy people from those with the disease.
The new test uses nuclear magnetic resonance, also called magnetic resonance imaging, to reveal differences in the magnetic properties of the blood plasma of cancer victims. The test finds these differences in the fat, or lipid, portion of the blood, but the reason for the differences is still unclear.
Many experts were unfamiliar with the development, which was described for the first time in a paper published in today's issue of the New England Journal of Medicine, and generally were cautious.
"I think the jury is still out," said Dr. Frank Rauscher of the American Cancer Society. "If this is as good as it sounds, then it's very good indeed."
Dr. Philip S. Schein, a cancer specialist at the University of Pennsylvania, said that if the test ultimately is sensitive enough to permit early detection of cancer among people with no symptoms, "it will be of great value in our effort to provide for the earliest possible detection of cancer."