There's nothing 'simple' about a blood test for cancer

Hello and happy Saturday! Here’s this week’s round-up of eclectic and under-the-radar health and medical science news.

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‘Simple’ blood test for cancer concerning

By Kelly Crowe

“If you ever hear about a simple blood test run for the hills because there is no such thing.”

That’s the advice from health journalism watchdog Gary Schwitzer, publisher of HealthNewsReview.org  a website aimed at helping the public assess health claims reported in the media.

Yet the promise of a simple blood test seems irresistible.

A quick Google search reveals a series of headlines over the last few months heralding the development of simple blood tests to find ovarian cancer, skin cancer, inflammatory bowel disease, concussions, PTSD, depression and Alzheimer’s — even though none of those tests is on the market yet.

And last week there was a new flurry of newsstories announcing another simple blood test — this one reporting the ability to detect eight different types of cancer.

“The test isn’t as good as the news reports would have you believe,” said Dartmouth professor Dr. Gilbert Welch, who has written about the limitations of any blood test that claims to detect cancer.

“This is fundamentally a really hard problem to detect the right mix of biomarkers and cell free DNA that’s predictive of an important cancer.”

Blood test cancer search results

‘The miscommunication of screening tests has been the most prevalent and troubling trend that I’ve seen by leading news organizations,’ says health journalism watchdog Gary Schwitzer. (Kelly Crowe/CBC)

The blood test, called CancerSEEK, is still in the early research stages of what will be a long and challenging development process. Yet those nuances were overshadowed by the excited headlines about a “breakthrough” blood test.

“I don’t think there’s any question that the miscommunication of screening tests has been the most prevalent and troubling trend that I’ve seen by leading news organizations,” said Schwitzer.

‘Messy area’

Even if that test was on the market, there would be nothing simple about it.

“As a population-based screening tool I think it’s a total Pandora’s box,” said Welch.

It would raise a series of ethical and clinical quandaries. How many actual cancers does it miss? How many false cancers does it detect?  And what does a positive result mean if there are no detectable tumours or other anatomical abnormalities?

“I fear that the minute people hear that they have a blood test compatible with cancer and the doctors in the front line can’t find it that’s going to be a terrible thing. I fear it will be very hard to put this to rest,” said Welch.

One risk is that widespread screening for cancer will turn healthy people into cancer patients.

Welch points to the controversies over the PSA test for prostate cancer, which discovers cancers which might never be dangerous yet could lead to patients being exposed to harmful side effects from treatment, including impotence and incontinence.

“The simple blood test to detect prostate cancer raised some of the most complex issues in medicine,” Welch said, adding that some of the early enthusiasm for widespread cancer screening is starting to wane.

“I think more and more of the medical community realize it’s a much more messy area than we originally imagined,” he said. “I think we originally imagined that any effort to diagnose a disease early would only help people, it wouldn’t hurt them.”

Still, Welch said the overall research into looking for cancer markers in blood is a valid area of study.

“I think there’s some settings where this makes a great deal of sense. I think it’s one thing in people with established cancers to use this kind of test and monitor their response to treatment or see whether their cancer is coming back. In that kind of surveillance or tailoring of therapy it may be very useful to be able to do that with a blood test.”

But rather than hyping the promise of a test that is not ready for prime time, the media should emphasize all the caveats and limitations.

“How many medical centres globally are getting phone calls or having patients asking for visits right now in response to stories like this?” said Schwitzer.

Oops! Never mind — the Nobel Prize edition

By Nicole Ireland

Another case of data falsification in a published scientific study surfaced this week. It may have  gone unnoticed if it weren’t for the offending researcher’s boss — a Nobel laureate.

Never mind blocks

‘Never mind’ might be a constant headline if mainstream media covered the more than 1,000 retractions from scientific publications counted by Retraction Watch every year. ( Yury Zap/Shutterstock)

On Jan. 22, Kyoto University in Japan announced it had completed an investigation into Kohei Yamamizu, an assistant professor at the school’s Center for iPS Cell Research and Application (CiRA), and found he had “conducted fabrication and falsification” of data in a study that was published in the American journal Stem Cell Reports.

Yamamizu was the primary author of the research paper, which developed a model for ways neurological drugs could bypass the blood-brain barrier. The university concluded that none of the other co-authors had anything to do with the misconduct.

But the person whose name drew headlines in the academic scandal was not Yamamizu.  Instead, it was his director, Shinya Yamanaka, who won the Nobel Prize in Physiology or Medicine in 2012 for his stem cell research.

Yamanaka had nothing to do with the fraudulent data, and was not even an author of the research paper. But as the head of the centre for which Yamamizu works, the Nobel laureate issued a public apology in a news release issued by the university.

“As CiRA Director, I feel a strong responsibility for not having been able to prevent research misconduct at our institute and sincerely apologize to all who support us and our research activities,” Yamanaka said.  

“We take misconduct very seriously. We will reevaluate our research management to strengthen our research ethics and to regain public trust in our research.”

Stem Cell Reports will be retracting the research paper, a spokesperson for the journal confirmed to CBC News on Friday.

Adam Marcus, co-founder of Retraction Watch — a blog that monitors retractions from scientific publications — said Yamanaka set the right example by apologizing and taking responsibility for work done in his research centre.

“It really doesn’t matter how smart you are or how many accolades you’ve received in science.  Things do go wrong, and occasionally people who work for you abuse your trust, and, you know, the trust of their colleagues,” Marcus told CBC News.

“Being a Nobel laureate does not necessarily mean that you’ve surrounded yourself with people of equal ability or integrity.”

Faulty work requiring retractions is “unfortunately not news,” Marcus said, noting that Retraction Watch covers roughly 1,000 cases a year — most of which don’t get mainstream media coverage.

But the good news is, the scientific community is working harder than ever before “to be more transparent and more rigorous,” he said, including coming forward with mistakes — something he hopes fosters trust among the public.

The story behind the story: No more Mr. Anonymous for sperm donors

By Emily Chung

Ever wonder where we get our ideas for health stories? Sometimes they come from the experiences of our friends and family. CBC science writer Emily Chung explains how she sparked the idea for this week’s story about the vanishing anonymity of sperm donors:

A few months ago, I met a friend for lunch and she shared an amazing story with me.

Her husband had given her a DNA test kit for Christmas because she was curious about her ethnic ancestry.

When my friend’s mother found out, she pulled my friend aside and confessed a long-held family secret — my friend’s father was not her biological father. She had been conceived with an anonymous sperm donor.

Laura McInnes and Erin Jackson

Erin Jackson (left) and Laura McInnes (right) both grew up thinking they were conceived the usual way and were being raised by their biological parents. They were shocked when they learned their parents used anonymous sperm donors. They’re featured in Emily Chung’s story. (Erin Jackson, Laura McInnes)

My friend had been an only child her whole life, but when her DNA test results came in, they showed some exciting news —  she had several half-siblings from the same donor, mostly in the Toronto area. She has since made contact and formed relationships with them, and they’re working together to learn more about their biological father and their paternal lineage.

My colleagues Melanie Glanz and Vik Adhopia had wanted to do some stories about home DNA test kits, and when I mentioned this story at a meeting, they were fascinated by all the issues it raised. While my friend couldn’t share her story publicly for family reasons, we soon found others in similar situations so we could explore those issues more deeply. This story is the result.

What happens to kids when parents supply the alcohol?

By Justin Li

There’s a commonly held belief that if parents are the ones to introduce their children to alcohol it leads to healthier drinking habits. At least that’s the theory.

“Some people believe it teaches young people appropriate safe social drinking behaviours as opposed to maybe learning drinking from your friends out behind the garage, so to speak, where you might be more likely to binge drink excessively or heavily,” said Dr. Robert Mann, senior scientist at the Centre for Addiction and Mental Health (CAMH) in Toronto.

However, a recent Australian study published in The Lancet Public Health suggests that might not be the case.

The study followed over 1,900 Grade 7 students in Australia for a period of six years, dividing them into four groups:

  • Those who were supplied alcohol by their parents only.

  • Those who were supplied alcohol by other means only.

  • Those who were supplied alcohol by both parents and other means.

  • Those not supplied alcohol at all.

The study found that those who got their alcohol only from their parents had higher odds of binge drinking, alcohol-related harms and symptoms of alcohol use disorder than those who were not given alcohol at all.

(Australian guidelines define binge drinking as more than four drinks at a single occasion, compared to five, as defined by Canada’s CAMH.)

Those who got alcohol from their parents and also by other means had the highest odds of binge drinking and other alcohol-related harms, likely due to increased exposure to alcohol.

The study also found that those supplied with alcohol by their parents in one year are twice as likely to access alcohol by other sources in the next year, which the authors suggest means parental provision has little to no mitigating effect when it comes to alcohol responsibility in teens.

Although Mann emphasizes that the causation is not immediately known, he says “the attitudes toward alcohol are much less restrictive” when parents provide young people with alcohol, which could in turn normalize consumption.

“It could be that young people are getting the message from their parents that it’s OK to drink and that transfers outside the home as well; ‘Mum and Dad let me drink at home, so it’s OK if I go to this bush party with my friends and drink a lot.'”

So how do parents make sure their kids are drinking responsibly?

Mann says CAMH figures have shown that alcohol use among young people has been experiencing a long-term decline. That’s due in part to educational and public awareness campaigns on the effects of alcohol. And at the same time people are being introduced to alcohol later in their younger years.

“One of the things that’s come out of the literature in recent years is that … early onset of alcohol consumption is associated with increased likelihood of problems both in the short term for young people and later on in adult years.”

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