Debunked cancer study about blood tests has wide ripple effects, Wall Street Journal reports

Research groups that have relied on data from an apparently flawed cancer study now must deal with criticism of the original findings.

Steven Salzberg, PhD

That's the conclusion of Steven Salzberg, a PhD computational biologist at Johns Hopkins University, according to a story by Nidhi Subbaraman in The Wall Street Journal last week.

Salzberg, whose critique, written with colleagues in the field, led to the study's recent retraction, is quoted as saying the faulty conclusions have "polluted the literature."

The WSJ piece says the lead researcher, Professor Rob Knight of the University of California, San Diego, had indicated the 2020 study had "reported that 32 different cancers, from prostate tumors to skin melanomas, harbored unique combinations of microbes, chiefly bacteria and viruses, that acted as fingerprints for each type of tumor. The idea had clinical significance: A blood test could allow physicians to use evidence of microbes detected in the blood as a proxy to diagnose the cancers."

Since the study's publication in 2020 in Nature magazine, more than 600 papers have cited it, Subbraman's article says, and at least a dozen groups based new work on its data. 

In addition, the initial co-researchers had "launched a startup to capitalize on their findings" — although support for it "has dried up" since the criticism became public.

Knight, "a heavyweight in the field of microbiology," the WSJ piece adds, had been "widely regarded as a pioneer of big-date microbial analysis. His resume lists multiple awards and prestigious fellowships at scientific societies, two books and a TED talk."

The original study analyzed data from more than 17,000 samples from over 10,000 people with cancer.

Among the problems discovered was that "some microbes the researchers flagged as components of cancer signatures weren't known to exist in humans." To boot, the critics, whose work was published in the journal mBio, apparently couldn't find "most of the bacteria reported in the Nature study."

Salzberg told The World Street Journal that "it wasn't a close call. This data is completely wrong."

According to the story, a wide ripple effect has followed the criticism: "The publishers and journal editors of eight studies have been reviewing the papers."

More details on studies that had to be retracted can be found in Rollercoaster: How a man can survive his partner's breast cancer, a VitalityPress book that I, Woody Weingarten, aimed at male caregivers.

'New frontier' blood tests to find cancer may create risks for patients, N.Y. Times story says

Blood tests that detect cancer can create risks for those who use them, according to a story by Gina Kolata a while back in The New York Times.

The article indicates that "the tests screen for cancers that often go undetected, but they are expensive and some experts worry they could lead to unnecessary treatments without saving patients' lives."

Some companies, Kolata's piece says, aren't waiting for Food and Drug Administration approval before they sell the tests. One of the companies, Grail, is selling an annual version, and a second company, Exact Sciences, plans to do the same, using a loophole provision "known as laboratory developed tests."

The tests, the story contends, "are a new frontier in screening. Companies developing them say they can find dozens of cancers."

Supporters of the tests insist they can "slash cancer death rates by finding tumors when they are still small and curable. But a definitive study to determine whether the tests prevent cancer deaths would have to involve more than a million healthy adults randomly assigned to have an annual blood test for cancer or not. Results would take a decade or longer."

While standard screening tests "are commonly used to detect cancer of the breast, colon, cervix and prostate," Kolata's article notes, "73 percent of people who die of cancer had cancers that are not detected by standard test."

The story quotes Dr. Tomasz Beer a cancer researcher at Oregon Health & Science University who is directing a Grail-sponsored study of the test. "We're at a point now where the blood tests are in their early days," he says, but "I think there's promise for a real impact."

Dr. H. Gilbert Welch

Dr. H. Gilbert Welch, a senior investigator in the Center for Surgery and Public Health at Brigham and Women's Hospital, raises a red flag: "Grail proposes to test every Medicare beneficiary every year, making it the screening test that could bankrupt Medicare."

Among other risks the story attributes to some doctors are that "some will have a positive test, but doctors will be unable to locate the cancer. Others will be treated aggressively with surgery or chemotherapy for cancers that, if left alone, would not have grown and spread and may even have gone away."  

Dr. Barnett Kramer, former director of the Division of Cancer Prevention at the National Cancer Institute and a member of the Lisa Schwartz Foundation for Truth in Medicine, according to Kolata's story, "fears that the tests will come into widespread use without ever showing they are beneficial" and hopes that "we are not halfway through a nightmare." 

Once the tests are being used broadly, he adds, "it is difficult to unring the bell."

More information about clinical trials can be found in "Rollercoaster: How a man can survive his partner's breast cancer," a VitalityPress book that I, Woody Weingarten, aimed at caregivers.

AP story suggests liquid biopsies may be 'a new frontier in cancer screening for healthy people'

Liquid biopsies, or blood tests that look for cancer by checking for DNA fragments shed by tumor cells, are being billed "as a new frontier in cancer screening for healthy people."

A story in this week's San Francisco Chronicle by Associated Press medical writer Carla K. Johnson notes that these tests already are being "used in patients with cancer to tailor their treatment and check if tumors come back."

But one California-based company, Grail, is promoting the $949 test, the article says, "as a way to detect tumors in the pancreas, ovaries and other sites that have no recommended screening method."

Most insurance companies do not cover the cost, and the tests are being marketed "without endorsements from medical groups or a recommendation from U.S. health authorities," Johnson's piece says.

The Associated Press also observes that Federal Drug Administration "authorization, clearance or approval of such tests is required by law, but the agency historically has not enforced most regulatory requirements for ones – like Grail’s – that are designed, manufactured and used within a single laboratory."

The story quotes FDA spokesman Jim McKinney as reporting that the agency is working with Congress on legislation "to update the regulatory framework, which would include active oversight for such tests."

Although Grill intends to get FDA approval, it currently is marketing its test "as it submits data to the agency."

Meanwhile, Johnson's piece says, "U.S. government researchers are planning a large experiment — with 200,000 participants and possibly lasting seven years — to see if the blood tests can live up to the promise of catching more cancers earlier and saving lives."

Dr. Lori Minasian

"They sound wonderful, but we don't have enough information," the story quotes Dr. Lori Minasian of the National Cancer Institute's Division of Cancer Prevention, who is involved in planning the research. "We don't have definitive data that shows that they will reduce the risk of dying from cancer."

Whereas screening tests — mammography, PAP, colonoscopy, for example — look for one cancer at a time, claims Dr. Joshua Ofman, an executive at Grail, the new blood tests look for many cancers at once, a definite advantage.

More information on testing for disease can be found in "Rollercoaster: How a man can survive his partner's breast cancer," a VitalityPress book that I, Woody Weingarten, aimed at male caregivers.

Experiment could lead to blocking metastasis

Blood test that finds 8 cancers before they spread is showing progress, scientists ascertain

A new study shows an experimental test may provide information that might stop eight cancers from metastasizing.

In an attempt "to try to find cancer before it spreads, when chances of cure are best," many groups are working on "liquid biopsy tests that look for DNA and other things that tumors shed into blood," the Associated Press says.

Findings of the study by Johns Hopkins University scientists, reported recently in the journal Science, indicate that the non-invasive tests were able to locate some 70 percent of the common types of cancer in 1,005 patients. 

"The rates varied depending on the type," the AP dispatch by Marilynn Marchione says, "lower for breast tumors but high for ovarian, liver and pancreatic ones."

The CancerSEEK test, which "detects mutations in 16 genes tied to the cancer and measures eight proteins that often are elevated when cancer is present," the story continues, also honed in on colon, lung, stomach and esophageal cancers. 

Researchers did not include prostate cancer because the PSA blood test already is widely used — though its value for screening has been questioned. 

The eight cancers currently have no screening tests for people at average risk. 

Nickolas Papadopoulos

According to Nickolas Papadopoulos, Ph.D. professor of oncology and pathology at Hopkins and one of the study's leaders, "We're very, very excited and see this as a first step."

However, he cautions, "we don't want people calling up" and asking for it.

That's because the new test "is nowhere near ready for use yet," the AP notes — "it needs to be validated in a larger study already underway in a general population, rather than cancer patients, to see if it truly works and helps save lives."

The Los Angeles Times also quoted Papadopoulos, to the effect that "the goal is to look for as many cancer types as possible in one test, and to identify cancer as early as possible. We know from the data that when you find cancer early, it is easier to kill it by surgery or chemotherapy."

Researchers say the test could cost around $500 based on current materials and methods. 

More information on research and clinical trials can be found in "Rollercoaster: How a man can survive his partner's breast cancer," a VitalityPress book I, Woody Weingarten, aimed at male caregivers.

DNA trials may end mammograms, colonoscopies

Doc expects blood tests that predict cancer recurrences to have major effect on millions

In the not-so-distant future, a single blood test may be able to locate cancer.

Dr. Salvatore Iaquinta

At least that's the prediction of Dr. Salvatore Iaquinta, "Highway to Health" columnist for the Marin Independent Journal and a surgeon at Kaiser Permanente San Rafael.

Noting in a recent piece headlined "Closing in on cancer" that "we already have blood tests to monitor for cancer recurrences," Iaquinta forecasts the end of mammograms and colonoscopies.

Biomarkers "that expose the presence of otherwise invisible recurrences," he indicates, are already known for "certain ovarian, prostate, breast, liver and pancreatic cancers."

The same applies to some thyroid cancers.

But researchers at Johns Hopkins, he notes, have now "announced their success developing a 'liquid biopsy' — a blood test to screen for cancer DNA."

And "for patients with colon cancer, the screening test found about 90 percent of all stage 2, 3 and 4 cancers."

Iaquinta adds that it was almost as important that false positives didn't result.

And although the experimental tests for breast, lung and ovarian cancers didn't fare as well, they did find "at least 45 percent of stage 1 cancers for each of these tumor types," he writes.

Researchers at Stanford, the doctor maintains, "have done the same sort of profiling with some types of lymphoma."

And the "Institute of Cancer Research in London also found a tumor DNA for breast cancer and has announced they can detect recurrent disease eight months before standard tests reveal it."

In the meantime, a different group at Stanford "used a similar test to detect the effect of chemotherapy on women being treated for breast cancer. They found that a blood test could predict how the tumor was responding to treatment within two weeks of the start of treatment, far earlier than the standard methods."

The experimental process is not yet available to the general public and is still expensive, Iaquinta explains, "because of the cost of DNA sequencing. But like everything else tech, the price will come down as scientists find easier, faster ways to run the tests."

He concludes that "the ability to detect multiple cancers from a simple blood draw will have a profound effect on millions, and ultimately billions, of lives."

More information about experimental drugs and treatments can be found in "Rollercoaster: How a man can survive his partner's breast cancer," a VitalityPress book I, Woody Weingarten, aimed at caregivers.