Colon cancer study backs blood stool screening test

NEW YORK (Reuters Health) - Although colon cancer screening is recommended by many organizations, less clear is which method is best to detect tumors and precancerous lesions. A new study in the New England Journal of Medicine suggests that a relatively inexpensive and non-invasive test may be just as effective as a colonoscopy.

Meanwhile, a 23-year study, also published in the journal, has confirmed that removing precancerous polyps, known as adenomas, during a colonoscopy can reduce the risk of death from colorectal cancer by half.

In an editorial in the Journal, Dr. Michael Bretthauer of Oslo University Hospital and Dr. Mette Kalager of Telemark Hospital, both in Norway, said that based on the results, "an appealing concept would be to use colonoscopy as a triage screening test, offering it once for everybody at 60 years of age" and using it to classify people into high- and low-risk categories. Low-risk people would not need further screening while those with adenomas would be evaluated regularly.

One in 20 Americans will develop colorectal cancer. About 140,000 cases are diagnosed in the United States each year, resulting in about 49,000 deaths, according to the National Cancer Institute. It is the third most common cancer worldwide.

Currently, the U.S. Preventive Services Task Force, a government-backed agency, recommends screening for people age 50 to 75 years by one of three methods: a colonoscopy every 10 years; annual stool testing; or a less-thorough look into the colon (known as flexible sigmoidoscopy) every five years in conjunction with stool testing every two to three years.

People often find the tests unpleasant, however.

For example, in the new study that compared stool testing with colonoscopy, only 34 percent went along with stool testing. The participation rate was even lower when colonoscopy was offered, even though doctors can use it to cut away those suspicious precancerous adenomas.

In theory, adenoma removal saves lives by preventing a tumor. Ann Zauber of the Memorial Sloan-Kettering Cancer Center in New York, chief author of the long-term evaluation of polyp removal, and her colleagues said their work demonstrates that.

"This study is showing both a reduction in colon cancer incidence and colon cancer deaths by removing the adenomas, and it's a long-term effect" she told Reuters Health in a telephone interview. "This is reassuring for people to come in for screening."

The conclusion is based on people who were sent for a colonoscopy between 1980 and 1990. The Zauber team compared their death rate to the estimated death rate from the Surveillance Epidemiology and End Results (SEER) program.

Over a period as long as 23 years, the rate from colorectal cancer among the 2,602 people who originally had adenomas removed was 53 percent lower than estimated from the SEER data. In all, 12 died from cancer in the removal group, while 25 had normally been expected to die of colorectal disease.

The lower rate includes the fact that 81 percent of the patients who had polyps removed continued to have periodic colonoscopies to check for growths.

Bretthauer and Kalager cautioned in their editorial that "the study mimics a situation in which 100 percent of the population complies with screening, which is not a real-life scenario."

CHEAPER, LESS INVASIVE TEST PERFORMS WELL

The COLONPREV study, being conducted in Spain, is designed to compare 10-year death rates in two groups: volunteers who received a one-time colonoscopy and volunteers who are being screened every two years using fecal immunochemical testing (FIT), a form of blood stool testing. A positive FIT test led to a colonoscopy.

After the first round of testing, the researchers report in the New England Journal of Medicine, colorectal cancer was found in 30 people in the 26,703-member colonoscopy group and 33 in the 26,599-person FIT group.

Colonoscopy uncovered twice as many advanced adenomas, about two percent of the sample vs. one percent.

But the chief author of the Spanish study, Enrique Quintero of Hospital Universitario de Canarias, told Reuters Health by phone that it was encouraging that the cheaper fecal test "detected half the advanced adenomas just in the first round."

The next round of FIT tests will uncover more growths, he predicted.

Death rates will not be examined until the 10-year followup is completed in 2021.

Quintero and his team also found that the people assigned to the FIT group were more likely to participate in screening than those who were in line for a colonoscopy.

The participation rates were 34 percent with the stool-sampling test compared to 25 percent for colonoscopy.

At this point in the study, the researchers concluded, "the numbers of subjects who needed to be screened to find one colorectal cancer were 191 in the colonoscopy group and 281 in the FIT group, and the numbers who needed to be screened to find any advanced (cancer) were 10 and 36."

That's important when the FIT test is so much cheaper than a colonoscopy, Quintero said. "This simple, non-invasive and cheap test is equally good at detecting colorectal cancer and identifying the high-risk individual that should undergo a colonoscopy."

And the complication rate, including bleeding, low blood pressure and slow heartbeat, was nearly five times higher in the colonoscopy group.

SOURCES: http://bit.ly/xJBNxg and http://bit.ly/xPLSv4 New England Journal of Medicine, February 23, 2012.

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Colon cancer study backs blood stool screening test

NEW YORK (Reuters Health) - Although colon cancer screening is recommended by many organizations, less clear is which method is best to detect tumors and precancerous lesions. A new study in the New England Journal of Medicine suggests that a relatively inexpensive and non-invasive test may be just as effective as a colonoscopy.

Meanwhile, a 23-year study, also published in the journal, has confirmed that removing precancerous polyps, known as adenomas, during a colonoscopy can reduce the risk of death from colorectal cancer by half.

In an editorial in the Journal, Dr. Michael Bretthauer of Oslo University Hospital and Dr. Mette Kalager of Telemark Hospital, both in Norway, said that based on the results, "an appealing concept would be to use colonoscopy as a triage screening test, offering it once for everybody at 60 years of age" and using it to classify people into high- and low-risk categories. Low-risk people would not need further screening while those with adenomas would be evaluated regularly.

One in 20 Americans will develop colorectal cancer. About 140,000 cases are diagnosed in the United States each year, resulting in about 49,000 deaths, according to the National Cancer Institute. It is the third most common cancer worldwide.

Currently, the U.S. Preventive Services Task Force, a government-backed agency, recommends screening for people age 50 to 75 years by one of three methods: a colonoscopy every 10 years; annual stool testing; or a less-thorough look into the colon (known as flexible sigmoidoscopy) every five years in conjunction with stool testing every two to three years.

People often find the tests unpleasant, however.

For example, in the new study that compared stool testing with colonoscopy, only 34 percent went along with stool testing. The participation rate was even lower when colonoscopy was offered, even though doctors can use it to cut away those suspicious precancerous adenomas.

In theory, adenoma removal saves lives by preventing a tumor. Ann Zauber of the Memorial Sloan-Kettering Cancer Center in New York, chief author of the long-term evaluation of polyp removal, and her colleagues said their work demonstrates that.

"This study is showing both a reduction in colon cancer incidence and colon cancer deaths by removing the adenomas, and it's a long-term effect" she told Reuters Health in a telephone interview. "This is reassuring for people to come in for screening."

The conclusion is based on people who were sent for a colonoscopy between 1980 and 1990. The Zauber team compared their death rate to the estimated death rate from the Surveillance Epidemiology and End Results (SEER) program.

Over a period as long as 23 years, the rate from colorectal cancer among the 2,602 people who originally had adenomas removed was 53 percent lower than estimated from the SEER data. In all, 12 died from cancer in the removal group, while 25 had normally been expected to die of colorectal disease.

The lower rate includes the fact that 81 percent of the patients who had polyps removed continued to have periodic colonoscopies to check for growths.

Bretthauer and Kalager cautioned in their editorial that "the study mimics a situation in which 100 percent of the population complies with screening, which is not a real-life scenario."

CHEAPER, LESS INVASIVE TEST PERFORMS WELL

The COLONPREV study, being conducted in Spain, is designed to compare 10-year death rates in two groups: volunteers who received a one-time colonoscopy and volunteers who are being screened every two years using fecal immunochemical testing (FIT), a form of blood stool testing. A positive FIT test led to a colonoscopy.

After the first round of testing, the researchers report in the New England Journal of Medicine, colorectal cancer was found in 30 people in the 26,703-member colonoscopy group and 33 in the 26,599-person FIT group.

Colonoscopy uncovered twice as many advanced adenomas, about two percent of the sample vs. one percent.

But the chief author of the Spanish study, Enrique Quintero of Hospital Universitario de Canarias, told Reuters Health by phone that it was encouraging that the cheaper fecal test "detected half the advanced adenomas just in the first round."

The next round of FIT tests will uncover more growths, he predicted.

Death rates will not be examined until the 10-year followup is completed in 2021.

Quintero and his team also found that the people assigned to the FIT group were more likely to participate in screening than those who were in line for a colonoscopy.

The participation rates were 34 percent with the stool-sampling test compared to 25 percent for colonoscopy.

At this point in the study, the researchers concluded, "the numbers of subjects who needed to be screened to find one colorectal cancer were 191 in the colonoscopy group and 281 in the FIT group, and the numbers who needed to be screened to find any advanced (cancer) were 10 and 36."

That's important when the FIT test is so much cheaper than a colonoscopy, Quintero said. "This simple, non-invasive and cheap test is equally good at detecting colorectal cancer and identifying the high-risk individual that should undergo a colonoscopy."

And the complication rate, including bleeding, low blood pressure and slow heartbeat, was nearly five times higher in the colonoscopy group.

SOURCES: http://bit.ly/xJBNxg and http://bit.ly/xPLSv4 New England Journal of Medicine, February 23, 2012.

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Ovarian cancer screening popular despite guidelines

NEW YORK (Reuters Health) - Despite expert guidelines and scientific evidence to the contrary, a third of U.S. primary care physicians believe ovarian cancer screening is effective and many would offer it to patients, according to a new survey.

Although the results don't necessarily translate into real practice, that means more than a million women might be offered the tests, which come with a hefty price tag and possible hazards, researchers say.

"Currently the evidence suggests that the harms of ovarian cancer screening exceed the benefits," said Dr. Laura-Mae Baldwin of the University of Washington in Seattle.

"That's why it is not being recommended."

Baldwin and her colleagues surveyed more than 1,000 doctors across the country, asking them questions about a hypothetical case of a woman presenting for her annual exam.

The details varied, but the risk of ovarian cancer never went beyond medium. That covers about 95 percent of American women, for whom guidelines unanimously advise against screening.

Still, 65 percent of doctors said they "sometimes" or "almost always" offered or ordered ovarian cancer screening for women at medium risk. For women at low risk, the number dropped to 29 percent.

Screening is done either as an ultrasound scan or a blood test called CA-125.

Although these tests have never been shown to save lives, a third of doctors in the survey nonetheless believed they work.

"There are some critical knowledge gaps related to ovarian cancer screening among physicians," said Baldwin, whose findings are published in the Annals of Internal Medicine. "I would suggest that women educate themselves about the risks and the benefits of the tests."

HARM BUT NO BENEFIT

According to the largest clinical trial published so far -- known as the Prostate, Lung, Colorectal and Ovarian, or PLCO, trial -- women screened annually for ovarian cancer were just as likely to die from the disease as those who didn't have regular screening.

Of some 34,000 women who got screened in that trial, 212 were diagnosed with ovarian cancer -- and less than half of those cases were picked up by screening, according to Dr. Saundra Buys, who worked on the findings.

Meanwhile, the test had a false-positive rate of 8.4 percent, causing more than 3,000 false alarms -- a third of which led to surgery.

"People get referred to tests they don't need. A lot of women end up getting surgery," said Buys, a cancer expert at the University of Utah School of Medicine in Salt Lake City.

"It's concerning that doctors believe ovarian cancer screening is beneficial, because there is plenty of data to show that it isn't," she told Reuters Health.

But she also cautioned that based on data from the PLCO trial, which was published after the new survey was done, only a few percent of women say they've actually had a CA-125 screening test or an ultrasound.

"I don't think there is a lot of ovarian cancer screening going on," Buys said. "Despite what they are saying they are not ordering the tests."

A woman's lifetime risk of getting invasive ovarian cancer is just over one percent, with half of women diagnosed at age 60 or older, according to the American Cancer Society.

Baldwin and her colleagues estimate that about 1.2 million women might be offered one of the two screening tests for the disease. A CA-125 test costs about $80, while an ultrasound runs at $600.

EVIDENCE 'CRUCIAL'

Even if the survey doesn't reflect real practice, Baldwin told Reuters Health doctors often adopt new screening tests before evidence is available on whether or not they work.

Dr. Usha Menon, who runs the Gynaecological Cancer Research Centre at University College London, pointed out that physicians who listed the U.S. Preventive Services Task Force (USPSTF) as a major source of influence were more likely to stick to the guidelines.

The USPTF is a government-funded advisory agency that assesses the evidence for medical practices. It finds no evidence that routine ovarian cancer screening saves lives, but points to a "significant potential for harms."

"By identifying critical knowledge gaps and the positive impact of the USPSTF guideline, the authors set out the first steps to promoting adherence to screening recommendations," Menon told Reuters Health by email.

"The practice of evidence based medicine is crucial both for the wellbeing of our individual patients and for the appropriate use of available resources," she added. "There is currently no evidence that ovarian cancer screening can save lives and it should not be offered outside clinical trials."

Menon coordinates the massive UK Collaborative Trial of Ovarian Cancer Screening, which involves more than 200,000 women. She said results from that trial can be expected in 2014.

SOURCE: http://bit.ly/an7XRm Annals of Internal Medicine, February 6, 2012.

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