New Blood Test Could Detect Some Tumors

Scientists reported Wednesday the development of a new blood test that could be used for early and reliable detection of certain types of tumors, including a form of lung cancer.

“It could be a screening test for diagnosing the presence of a wide variety of tumors, some of which are difficult to diagnose any other way,” said Dr. Leonard J. Deftos, who helped develop the test at the Veterans Administration Medical Center in San Diego.

More studies are needed on a large number of patients to determine how accurate and useful the test would be, and it would be several years before the test could be widely available, Deftos said.

One Type of Lung Cancer

By detecting high levels of a certain type of protein, the test could give early warning to the presence of tumors in endocrine glands, such as the thyroid, pituitary and adrenal glands, one type of tumor in the pancreas and one type of lung cancer known as “oat cell” tumors.

The American Cancer Society estimated that there will be about 43,000 new cases of these types of cancer in 1986.

“I don’t know any other single test that is of potential diagnostic usefulness for such a wide variety of tumors,” Deftos said.

In a study published in the New England Journal of Medicine, researchers measured the level of the protein chromogranin A in the blood of 103 patients suffering from a variety of these types of tumors.

Up to 100% Accurate

Using a radioactive substance to measure the protein, the researchers found that levels of chromogranin A in cancer patients were as much as 1,000 times higher than normal. The test was reported accurate up to 100% in spotting tumors.

Early diagnosis of the tumors would enable doctors to treat patients more effectively, possibly performing surgery before the tumors become too large, Deftos said.

The test would be most useful for people who are considered to be at high risk because they smoke cigarettes or have relatives who have had the cancer, Deftos said.