Cancer, bad luck and some lessons in science reporting

Arvind Suresh | January 16, 2015

If you follow science and or healthcare news, by now you’ve probably heard of the ‘cancer is mostly caused by bad luck’ claim that news outlets everywhere have been reporting. If not, here’s a quick run down. Headlines in leading outlets such as NY Times (“Cancer’s Random Assault”), Washington Post(“Biological bad luck blamed in two-thirds of cancer cases, researchers say” and Guardian (“Two-thirds of adult cancers largely ‘down to bad luck’ rather than genes”) caught on to a study published in the prominent journal Science by cancer researcher Bert Vogelstein and biomathematician Cristian Tomasetti at Johns Hopkins University.

The researchers analyzed the degree to which the risk of acquiring cancers could be attributed to random mutations occurring in stem cells. The theory was that since stem cells divide more often than others, they had a higher probability of accumulating cancer causing mutations. Upon analysis, the team found a high degree of correlation between rates of stem cell division in different tissues and the occurrence of cancer in those organs. From their statistical analysis, they also surmised that approximately two-thirds percent of the variation in cancer cancer risk could be explained by random mutations alone.

Both the press release from Johns Hopkins and the editorial accompanying the paper in Science boiled the study down to this – most cancers could be attributed to bad luck. Needless to say this kind of framing, especially about a disease that is as poorly understood as cancer was begging to be sensationalized by the news. And it was. In a big way.

There was immediate backlash however, with the media reports being widely criticized as being inaccurate and poorly researched at best and dangerously misleading at worst. Why misleading? Attributing the occurrence of cancer to ‘luck’ public health experts believed, dismissed important medical advice about environmental causes of cancer such as exposure to toxic chemicals and smoking which could lead people to underestimate the importance of lifestyle factors.

The study even managed to catch the ire of the International Agency for Research on Cancer, the WHO’s specialized cancer agency which issued a statement (emphasis mine)

The International Agency for Research on Cancer (IARC), WHO’s specialized cancer agency, strongly disagrees with the conclusion of a scientific report on the causes of human cancer by Dr Cristian Tomasetti and Dr Bert Vogelstein, published in the journal “Science” on 2 January 2015 and widely reported in the mass media.

The study suggests that random mutations (or “bad luck”) are the major contributors to cancer overall, often more important than either hereditary or external environmental factors.

“We already knew that, for an individual to develop a certain cancer, there is an element of chance, yet this has little to say about the level of cancer risk in a population,” explains IARC Director Dr Christopher Wild. “Concluding that ‘bad luck’ is the major cause of cancer would be misleading and may detract from efforts to identify the causes of the disease and effectively prevent it.”

According to current knowledge, nearly half of all cancer cases worldwide can be prevented.

Biostatistician Bob O’Hara and an evolutionary biologist writing under the pseudonym GrrlScientist wrote a scathing response to media coverage in the Guardian titled “Bad luck, bad journalism and cancer rates” where they explained the statistics behind the study. They ended their piece saying

Please, journalists, get a clue before you write about science

Andrew Maynard of the University of Michigan Risk Science Center while offering a detailed analysis of the paper and the press release also pointed out the pittfalls of the study the nature of the reporting. He was a little easier on the media however, noting that reporters were not solely to blame.

In the case of this paper, it’s hard to see clear evidence of bad reporting. There is a lack of balance and contextualization though that, it seems, has its roots in the original paper.

Would the media coverage have been different if the work was pitched differently? It’s hard to tell – but in this instance I’d certainly be hesitant to put all the blame on bad journalism.

Amidst all the backlash however came out an interesting and frankly, refreshing piece written by Jennifer Couzin-Frankel, the author of the Science editorial. In a piece titled “Bad luck and cancer: A science reporter’s reflections on a controversial story,” she reanalyzes her reporting and questions whether she could have done better

Given the furor, I wondered: Had I gotten it wrong? Had the authors? Answering these apparently straightforward questions proved surprisingly difficult, exposing the challenges that come with communicating science, and the desire by scientist-authors and reporters to streamline the story they’re trying to tell.

I began with my own story, working backward to the science that spawned it. I’d written that the theory of random mutations in stem cells “explained two-thirds of all cancers.” Immediately, I knew that I had written part of that sloppily, to put it generously: The study didn’t include all cancers.

She goes on to write about reaching out to the study author again for a clearer explanation, how it took her many more hours to fully understand the two-thirds figure and why the conclusions of the paper did not mean that most cancers were due to bad luck.

I’m confident that Couzin-Frankel was not the only reporter to have experienced difficulty in reporting on this study. I found the statistics difficult to grasp as well, and placed in a similar situation, I’m not sure I could have done better, despite my background in life sciences research (indeed, given my limited reporting experience, I might have fared worse). Biostatistician David Spiegelhalter from the University of Cambridge and study author Christian Tomasetti comment on the complexity of the research in her piece

That said, errors were made along the way, a fact that didn’t surprise him. “This is incredibly difficult stuff,” Spiegelhalter continued. “I do feel for you. It’s one of those things that’s so superficially simple, and yet the superficial simplicity is not correct.”

Tomasetti was sympathetic. “There are lots of scientists that need clarification” on this paper, he said, along with some statisticians. He was busy preparing a technical report with additional details, and Johns Hopkins had just put out a press release explainer.

Clearly, this is not an easy problem to solve – journalists with tight deadlines dealing with exceedingly complex information along with press releases that need to generate hype to some extent make a situation ripe for misreporting.

However, initiatives like the newly formed Genetic Expert News Service (GENeS) are trying to help with the problem (Full disclosure: I will be joining the staff of GENeS starting February 2015). A joint project of the GLP and the World Food Center Institute for Food and Agricultural Literacy (IFAL) at the University of California, Davis, GENeS aims to make sure that scientific information is reported accurately by connecting researchers and reporters.

Robin Bisson, director of GENeS speaks about the project and how it might have helped in the reporting of the bad luck cancer study:

The difficulty with the ‘bad luck cancer study’ was understanding the nuance of precisely what the research results were, which is essentially a matter of understanding the methodology. That is a key part of what GENeS will provide: we are recruiting statisticians who are able to analyze and explain how studies are designed and what conclusions can be drawn.

Explaining the broader goal of the service in SciLogs he writes,

We are building a database of researchers from across North America willing to be called on when a news story comes up in their area of expertise.

We will also provide an inquiry service to match researchers on our database to requests for expertise, which we will make available to any organization publishing or engaging with debates around genetics and biotechnology.

What is interesting here is that despite all the uproar, the story would have died down inevitably, and scientists and communicators would have added another strike to the ‘sloppy reporting’ column before moving on. But by publishing her self evaluation on Science, Couzin-Frankel brought the issue back into media focus, turning it into a teaching moment for everyone involved – researchers, journalists, press officers and readers. She points out the lessons she learned from this issue

The paper’s bottom line wasn’t simple, but the message for me was: Science is complicated, and people care deeply about the biology of diseases that affect their loved ones and themselves. Distilling the story—with space constraints, with a desire for clear writing that will hold readers’ attention and help them understand—carries risks for scientists and for journalists. They are ones I hope never to forget—even if I err now and again.

Here’s hoping for more such moments in the future.

Arvind Suresh is a science communicator and a former laboratory biologist. Follow him @suresh_arvind

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