Study shows simple screening test to be life saver

WASHINGTON _ A simple screening test for blood in the bowel can reduce by up to one-third the death rate from colon cancer, the second leading cause of cancer death in the United States, a study says.

The finding, to be published Wednesday in the Journal of the National Cancer Institute, is prompting a national campaign to encourage people over age 50 to take the test, because they account for most of the 56,000 U.S. colon cancer deaths each year.

Minnesota researchers monitoring the health of 46,000 volunteers since 1976 have found that those who take the fecal occult blood test each year have 33 percent fewer deaths from colon cancer than people who do not take the test. Those tested every other year, the study found, have a 21 percent reduced rate of colon cancer death.

"When you have a positive test for blood, the likelihood of finding a growth in the colon is about 35 percent," said Dr. John H. Bond, the study's co-author. "About 9 percent will have cancer, and the rest will have significant precancerous polyps in the colon."

An analysis of the long-running study in 1993 suggested that annual tests could reduce deaths from colon cancer, and now the new analysis shows that even biennial tests can have a dramatic effect, said Bond, a professor of medicine at the University of Minnesota and a staff physician at the Minneapolis Veterans Affairs.

"It is a very valuable way to identify people who are healthy and have no symptoms, who nevertheless have a developing cancer in their colon."

The results confirm findings from two earlier studies in Europe, he said.

Prompted by the research results, federal health agencies on Tuesday announced a new campaign to encourage all Americans over 50 to take the fecal occult blood test.

"The good news is that we can prevent many deaths from colorectal cancer through screening," said Surgeon General David Satcher. "If you've celebrated your 50th birthday and have never been screened for colorectal cancer, start now."

Under a program that went into effect last year, Medicare now pays for the screening, officials said.

About 129,000 Americans, most past the age of 50, are diagnosed each year with colorectal cancer, and about 56,000 die each year. It is the second most common cancer killer, just behind lung cancer.

The fecal occult blood test used in the Minnesota research has long been a common part of physical examinations.

Using a card with small inserts, patients collect specimens for the tests at home. Fecal specimens from several bowel movements are placed into the insets, and the self-sealing card is then mailed or delivered to a doctor's office where a chemical is applied to each specimen. If the chemical turns blue, it is evidence of blood.

If the test is positive, patients then undergo a full colon examination with a flexible tube, Bond said. This exam, called a colonoscopy, will find any evidence of cancer or of precancerous growths called polyps.

Removing the polyps, performed during the full colon exam, stops the growth from becoming cancer in most cases, he said.

"This type of cancer is preceded in 95 percent of the cases by slowly growing polyps," Bond said. "By taking out the polyps, one can reduce subsequent development of cancer by 90 percent."

The fecal blood tests give false positives 65 percent of the time, Bond noted. But he said "that 35 percent (where a growth is found) is sufficiently high to warrant the examination."

The fecal blood test costs about $10, said Bond. The follow-up colonoscopy examination can cost several hundred, but he said it is "very cost effective" from a public health viewpoint.

"The cost of the screening and the follow-up tests is much less than finding and treating the cancer later, not only in money, but in the pain and suffering of the patients," said Bond.