Does talcum powder cause cancer? (Based on the news coverage, I have no idea!)

 

The Guardwww.johnsonsbaby.comian reported yesterday that the family of a woman who sadly died of ovarian cancer is to recieve $72 million dollars from Johnson and Johnson: the world’s biggest maker of healthcare products. The family claimed she died as a result of several decades use of the talc based “Baby Powder”, one of the company’s popular products. This seemed a little unusual as talc (aka H2Mg3(SiO3)4 or Mg3Si4O10(OH)2) is a naturally occurring mineral and, from an epidemiological perspective, causation is very difficult to prove.

In my 5 years as a health researcher I’ve never even considered that baby powder could be a cause for cancer. I use the powder in my basketball sneakers to absorb moisture and prevent them from stinking up my house. So, I immediately had questions. Should I now worry about an increased risk of cancer? Should I throw out my shoes? Should I warn all my friends? There must be some solid evidence supporting a link. Why else would a court award someone $72 million dollars?

What surprised me was not the claim that talc might cause cancer but that after having read the article none of my questions had been answered. There was no reference to evidence and there was no explanation of what the potential risks are.

How can we make our own judgements about the link between cancer and talc? How do we know if we need to be concerned about our health or our families’ health?

Why does this matter?

Without any discussion of the strength of evidence supporting health-related claims or of the potential increased health risks the public (I know I am!) are likely to be really anxious. Some may be wondering if this something they need to speak to their doctors about and whether they should stop using baby powder.

To find the evidence I typed “Johnson and Johnson 72 million Cancer” into google. I opened the first 10 articles about the results of the lawsuit to find out how many cited or referenced specific research studies and how many quantified the potential risks.

Here’s what I found

Only 20% (see table below) cited or referenced specific studies examining the link between talc and cancer and only 20% quantified the potential risks associated with use of talc.

This lack of evidence and risk communication highlights a serious and pervasive issue in the reporting of health-related news stories: the public is not given the health information they need to make their own judgements. Risks and evidence can be well-summarized and communicated so the public can understand and make informed decisions about their health. Journalists ought to provide this information and the public ought to demand it.

I finally came across a BBC article that answered some of my questions. The BBC spoke to Ovarian Cancer experts who discussed specific studies and evidence (although they didn’t provide a reference list) which suggested that the evidence was mixed and warned of potential bias and uncertainty in the studies: “Even if there is a risk it is likely to be fairly small…studies have shown that talc use increase risk of ovarian cancer by about a third…to put it into context, smoking and drinking increases the risk of oesophageal cancer by 30 times.”

In my next article I will find, appraise, and summarize the evidence myself to determine if talcum powder really does cause cancer and if I should throw out my favourite basketball shoes.

 

bobrovitz

This blog was written by Niklas Bobrovitz, a PhD candidate in the Nuffield Department of Primary Health Care Sciences at Oxford University, a Clarendon Scholar, and a member of the Centre for Evidence-Based Medicine.

niklas.bobrovitz@gtc.ox.ac.uk  @nikbobrovitz

 

 

Guardian Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

Reuters

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

Telegraph

 

Quantified the potential risk: yes

Discussed specific studies: no

Provided references to specific studies: no

Science alert

 

Quantified the potential risk: yes

Discussed specific studies: yes

Provided references to specific studies: yes

Bloomberg

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

US news

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

Money CNN

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

Good house keeping

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

Washington Post

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: yes

Daily Mail

 

Quantified the potential risk: no

Discussed specific studies: no

Provided references to specific studies: no

 

bobrovitz

Nik Bobrovitz

About Nik Bobrovitz

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3 comments on “Does talcum powder cause cancer? (Based on the news coverage, I have no idea!)

  1. Great point – it’s *so* irritating when sources aren’t cited (especially in online pieces where it’s so easy to bung a link in, even if you can’t be bothered with Harvard or Vancouver!). This particularly applies to articles about new research – where the original paper itself is not referenced!
    I hope this turns into a movement. Perhaps there should be a league table somewhere & annual awards for those that *do* cite sources? QC for popular media!

  2. Great idea and nice clear way to outline absence of evidence and that legal is not always science based. Critical appraisal is the key to understanding claims.

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