nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
See here for more discussion.

Monday, June 14, 2010

New Media Fodder: Cancer And High Blood Pressure Medicine

Angiotensin-receptors blockers (ARB's) linked to cancer.

You're gonna see some discussion on this one.  It's the kind of thing the media likes to hype (and gets people to pay money to read or hear about it).

So many people take medicine for high blood pressure (HBP) that the total number of people on this group of drugs is huge.  Maybe some of you have hypertension (HT), and take these or some other drug...or both.

Before I discuss the evidence, let's be clear that there's no question here that drug companies had this knowledge ahead of time (as was alleged with Vioxx).  There's probably no question that this should have been discovered before the drugs were approved.

Why?  Because it took looking back at the history of patients who took the meds for a long time, and the researchers had to pool the data for many studies to get about 60000 people with cancer, in order to discover the effect.  Unless you want to wait 50 years for every new drug to be approved, there's a limit on how much research you can do for each drug that's developed.

Bottom line, nobody at this point is saying that the process for approval was flawed.

So how much of a risk did they discover?  A little (see here).

For Onion Peelers (statistics, yuck),
Patients had a significantly increased risk of new cancer occurrence compared with patients in control groups (7·2% vs 6·0%, risk ratio [RR] 1·08, 95% CI 1·01—1·15; p=0·016).  Among specific solid organ cancers examined, only new lung-cancer occurrence was significantly higher in patients randomly assigned to receive ARBs than in those assigned to receive control (0·9% vs 0·7%, RR 1·25, 1·05—1·49; p=0·01). No statistically significant difference in cancer deaths was observed (1·8% vs 1·6%, RR 1·07, 0·97—1·18; p=0·183).

Note that new cancer occurred in patients NOT taking ARB's at a rate of 6%.  The rate for ARB's  was 7.2%.  Not a huge difference--and gives a relative risk of only 1.08.  So keep that in mind.  Also, almost all the study subjects were taking only one of the seven ARB's on the market.  We don't know which one, or if some or all, are a part of this effect.  Nor do we really know it's the drug.  Maybe it's the type of hypertension that needs this drug to control, or the type of patient who gets the type of hypertension that needs this group of drugs.  You see the point, I think.  We need more data, because ARB's are GREAT for HBP and have shown some kidney and heart disease improvement effects that you don't get with most other HT drugs.

Another interesting thing I found was that there was no difference in cancer "deaths" between the two groups. So there's a small increase in cancer, but people don't die of it?  Maybe...

How concerned should we be?  Compare this to some other risks?  Like dying in an auto accident this year (1 in 6500), a plane crash (1 in 400,000), struck by lightning (1 in 6.2 million). 

Or, take a look at John Stossel's classic video  report on Scaring Ourselves To Death.  Done back in the 90's, but superb on the psychology of our perceptions of risk.  If you follow just one recommendation from me to watch a video make it this one, a 3-part series (here, from The Freedom Channel blog).

Recommendation on high blood pressure pills:  Hold your horses on the hyperbole until more research is done.

Doc D

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