“A Pill to Prevent Breast Cancer” – Let the Listener Beware
The lead health news story for the vast majority of national news outlets today is “a pill that can prevent breast cancer.” If you heard this tantalizing lead-in, but missed the rest of the story – read on.
As I labored away on the treadmill at the gym earlier today, excited chatter from the early-morning news crew on TV suddenly caught my ear: “Coming up next: a pill that can prevent breast cancer.”
“Really,” I thought – skeptically. “Let’s see what they’re glossing over this time.”
I’m not a cynic, honestly I’m not. But too many times I’ve heard these sound bites about breast cancer, and discovered that they’re either reports about months-old research that have suddenly worked their way up to the national news desk; or “news lite,” sketchy information about new research that, when you delve into it, turns out to be an early-on trial involving lab mice, with any possible impact on human breast cancer light years away.
There’s a third way to position breast cancer research so that it appears newsworthy, and that’s what happened around the country today.
Let’s call it “risk abatement exaggeration.” Followed by “promoting the positive, demoting the negative.”
Here’s the information that started the news wires humming:
“San Antonio, Texas – The aromatase inhibitor anastrozole cut the incidence of breast cancer in half among high-risk postmenopausal women who took it for 5 years, researchers announced in the first results of the International Breast Cancer Intervention Study II (IBIS-II) trial.” (Johnson, 2013)
Let’s look at the details behind this information, in the stark light of practical reality.
Anastrozole (Arimidex, to those of us who’ve had to take it) was tested as a chemopreventive (a drug to prevent cancer) in a test involving 3,864 postmenopausal women, aged 40 to 70, who were considered at high risk for breast cancer due to family history; high breast density; or certain types of atypical breast cells (e.g., LCIS). (Johnson, 2013)
Among women who didn’t take Arimidex but were given a placebo, 4% developed breast cancer; for those taking Arimidex, the number was 2%.
So yes, Arimdex cut the incidence of breast cancer in half. This way of looking at data is called “relative risk.”
But you can also see it in terms of absolute risk: women taking Arimidex lowered their risk of breast cancer by 2%.
Any reduction of breast cancer risk is good news, of course. But see how much more exciting – more newsworthy – “cut in half” sounds than “lowered by 2%?” Still, they’re stating the exact same fact. This is the “risk abatement exaggeration,” and it’s something I hear on the national news all the time.
Caveat emptor: when digging into breast cancer research results, work your way past the hype to the real information: the numbers themselves, presented in absolute rather than relative terms.
So OK, if you’re a postmenopausal woman with a good, clinical reason to suspect your risk of breast cancer is higher than average, you might be interested in lowering your potential risk by even 2%. And that brings us to the second thing that struck me about today’s news: how Arimidex was being presented as a “no brainer” way to lower breast cancer risk.
The study revealed that women taking Arimidex experienced muscle aches and bone pain, as well as an increase in high blood pressure.
According to the study’s lead investigator, Jack Cuzick, PhD, a London researcher, “Mostly the aches and pains associated with estrogen loss were similar to [what is seen] with tamoxifen, and when you compare [them with] placebo, most are not drug-related. The major side effect that we were concerned about was for fractures, but it looks like we know how to control that by just doing a bone-density scan upfront [and bisphosphonate treatment if necessary].” (Johnson, 2013).
I’d like to add some real-life experience to Dr. Cuzick’s conclusions, based on my experience, and the experience of many of my friends, all of whom found the following:
•The muscle and bone pain associated with tamoxifen is slight to non-existent. The muscle and bone pain associated with Arimidex is significant, often enough to adversely affect day-to-day living.
•The muscle and bone pain begins when the drug is started, and ends when the drug is stopped. Not drug-related? Hmmm…
•Arimidex promotes bone loss. Many women choose to fight this bone loss by taking bisphosphonates, bone-loss prevention drugs that can produce horrendous gastrointestinal side effects, some so severe that the drug needs to be discontinued.
As it happens, Dr. Cuzick is on the speaker’s bureau for AstaZeneca, the drug giant that manufactures Arimidex. The study was also partially funded by AstraZeneca.
This relationship between researchers and Big Pharma isn’t unusual; it’s simply worth recognizing, and using as a lens through which to view researchers’ conclusions – and the resulting newscasters’ proclamations.
Bottom line: when the news around any new breast cancer research sounds too good to be true – it probably is. Not because the data isn’t true; but because it often gets a huge spin on its way from the lab to the news desk.
As an empowered patient, it’s your job to see through the hype. Your health depends on it.
Johnson, K. (2013, December 12). Anastrozole halves breast cancers in prevention study. Retrieved from http://www.medscape.com/viewarticle/817775