The other Chicago Tribune “village quack” spews on birth control and breast cancer

Blogging on Peer-Reviewed ResearchThe other village quack of the Chicago Tribune has decided to enter the breast cancer fray again.

No, I’m not talking about the main village quack of the Chicago Tribune. That would be Julie Deardorff. Rather, I’m talking about the Chicago Tribune‘s newly minted breast cancer crank, Dennis Byrne. We’ve met him before, parroting credulously an incredibly bad study claiming that it had found a slam-dunk association between abortion and breast cancer. How bad was the study? Well, it was so bad that it was published in that bastion of politically-motivated pseudoscience, the Journal of American Physicians and Surgeons. I had a fine old time dismantling the study that Byrne found so convincing, as did Mark Chu-Carroll, Mark Hoofnagle, and the Arch Pundit. Clearly, that Byrne found that study so convincing tells me right off the bat that he has no clue when it comes to evaluating scientific studies, and he proceeds to prove me right in a spectacular fashion, as he cherry-picks a study that purports to show that oral contraceptive pills increase the risk of premenopausal breast cancer. But first, a little playing the martyr always comes in handy:

Not wanting to become known as the town quack, I am reluctant to write another politically incorrect column about breast cancer.

Four weeks ago, when I reported a study that found a statistical link between abortion and breast cancer, the hate e-mail poured in, denouncing me for being an ignorant, stupid, anti-science, anti-choice and anti-woman lunatic.

Based on his previous article, I agree that Byrne was ignorant, stupid, and anti-science. I have no idea if he is anti-choice (although his falling for such a crappy study that claims to show that abortion causes breast cancer is highly suggestive that he is is likely to be) or anti-woman. I also doubt that he’s a lunatic, but he is definitely in over his head when it comes to evaluating any sort of scientific study. Of course, that doesn’t stop him for more than a second. Perhaps chastened a bit but still defiant, Byrne marches right back into the fray:

Yes, I know, this debate has been going on for years, if not decades, and judging by the last studies given wide exposure a few years ago by the media, the issue seems settled: Oral contraception does not significantly increase the risk of breast cancer.

There’s just one problem. According to an analysis in one of the most credible peer-reviewed journals in the country, the Mayo Clinic Proceedings, the risk is real. The study employed an often-used medical research technique called “meta-analysis” that allows researchers to combine data from other studies on the risk to get a larger picture. The result: Premenopausal women who used oral contraceptives prior to having their first child have a 44 percent higher chance of getting cancer than women who didn’t use the pill. If they used the pill for more than four years prior to their first full-term pregnancy, the risk increased 52 percent. Chris Kahlenborn, an internist at the Altoona (Pa.) Hospital and the study’s lead author, suggests one additional woman in 200 could get breast cancer. Extrapolated throughout the population, that could mean thousands more cases every year. I’d say that’s an important story.

Of course, I can’t resist pointing out that the Mayo Clinic Proceedings is hardly “one of the most credible peer-reviewed journals in the country.” It’s an OK journal, but certainly nowhere near top-tier. In fact, it’s probably at best in the middle third and at worst in the lower third of journals. Certainly its impact factor is nothing to be that impressed about. We’ll take a look at the study itself in a moment, but first let’s hear Byrne whine about the conspiracy of silence the mainstream media supposedly has about this story:

The reaction? Nearly total silence. Since it was published more than a year ago, I couldn’t find a single reference to it in the archives of the New York Times, Washington Post, Los Angeles Times or this paper. The Associated Press appears not to have covered it. I couldn’t find a single mainstream media article about it in a Google search. But stories about other breast cancer risks were plentiful, including one about how sleeping with a night light on can increase your chances of getting breast cancer. The National Institute of Cancer doesn’t mention the study on its Web site, but it did detail a 5-year-old study claiming to find no higher risk to pill use. The American Cancer Society also doesn’t mention the study and concedes only that “it is still not clear what part” the pill plays in breast cancer. Such guidance, if not deceptive, is certainly incomplete.

Oh, no! Those dastardly journalists! In their leftist, ideologically driven desire to abort fetuses and encourage promiscuous sex, the better to enslave women in their horrific anti-life and anti-Jesus ideology, once again they’re ignoring evidence of how deadly the pill supposedly is to women, as they did a couple of months ago with the dreaded abortion-breast cancer link! Or so Byrne would have you believe. It couldn’t, perhaps, be that this study didn’t cause much of a stir because it’s rather unimpressive, could it? Of course not. It must be a ideological blindness.

So let’s look at the study itself, entitled, boringly enough, Oral contraceptive use as a risk factor for premenopausal breast cancer: a meta-analysis. Yes, it’s a meta-analysis. To me that makes me rather suspicious right off the bat. Over the years, I’ve become more and more suspicious of meta-analyses. The main reason is that they are totally dependent upon the studies chosen to analyze and are an excellent example of “Garbage In, Garbage Out.” Not that the studies that were chosen for this meta-analysis were “garbage,” but perusing the list of them does reveal a couple of peculiar things. First, Kahlenborn includes studies dating back to 1980, which is curious. Women likely to have been developing breast cancer in the 1980s were also likely to have taken a version of the pill in the 1960s and 1970s that contained considerably more hormone in it than today’s versions of the pill. Another peculiarity is that there were few studies after 2000 included. Kahlenborn states that this was chosen to allow comparison between earlier studies, where few women took the pill before having their first child to later studies, where more and more women take the pill for a period of time before having their first children. In this, he reveals a major potential confounding factor that wasn’t even discussed in the study, namely controlling for number of children delivered and age at first childbirth. It has been well established that giving birth to more children decreases the risk of breast cancer, as does having a child at a younger age. Hmmm. You don’t think that maybe, just maybe, women who take the pill at a younger age, before having children, may be delaying having children, do you? Even Kahlenborn has to concede: “Hence,we could not adjust for potential confounders, such as age at menarche and age at first birth.” He goes on to handwave a bit about why he thinks this isn’t a problem, but he’s not convincing.

In other words, this study is nothing new and, like Byrne, not that convincing. And don’t even get me started about how publication bias alone might have accounted for such a small increased risk in a meta-analysis.

Of course, if Byrne were truly interested in “telling women the truth” about the pill, he could have done a literature search. If he did, he would have found that there is a good evidence that the pill decreases the risk of ovarian and endometrial cancer and growing evidence that it may decrease the risk of colorectal cancer. These benefits have to be balanced against the known low risk of thrombotic events and, possibly, a slightly increased risk of breast cancer, if the risk even exists. In terms of cancer alone, even if the Kahlenborn study is 100% correct, one would have to balance that 1 extra case of breast cancer in 200 women with how many fewer women would get other cancers. But a careful discussion of the relative risks and benefits of the pill is not what Byrne is about. He’s about scaring women with the breast cancer bogeyman.

More amusing is that Byrne apparently didn’t even bother to look into Kahlenborn’s history at all. From Completely Unnecessary, I learn that Dr. Kahlenborn’s work is very much favored by One More Soul, a “non-profit organization dedicated to spreading the truth about the blessings of children and the harms of contraception,” where it is claimed that contraceptives destroy marriages, degrade women, and “treat children like a disease.” Indeed, Kahlenborn has even written a pamphlet How the Pill and Other Contraceptives Work for One More Soul. In fact, he’s even released a “revised and updated” edition after the Mayo Clinic Proceedings study, and the blurb states:

Newly revised and updated in September 2007. How the Pill increases the risk of breast cancer, and effective strategies for prevention. Women who take contraceptive pills before their first full pregnancy are 44% more likely to develop breast cancer before menopause. This is a real eye opener for people who thought the Pill was harmless.

You’d think that if Kahlenborn wasn’t a crank, he’d try to distance himself from these organizations or at the very least wouldn’t use his research to push an agenda, but instead he is using the legitimacy of the journal in which he managed to get his meta-analysis published to push his “the pill causes breast cancer” fear-mongering.

Most hilarious is this comment by Byrne near the end of his article:

As for me, I am not opposed to contraception, oral or otherwise. I am not plotting to get the pill banned. I am not writing this column for hidden religious reasons. I am not saying that the Kahlenborn study is the last word; I’m not a scientist, so I can’t vouch for its methodology or conclusions. Just like the abortion/breast cancer study, I’m writing about it because people have a right to know about the existence of health information, even if it is contradictory to the given wisdom.

Touchy, touchy, Dennis. Settle down. Take a deep breath.

I love the way he’s taking the “I’m just sayin’, you know” defense so beloved of the crank journalist, cloaking his agenda in “the public’s right to know.” Never mind that he’s openly advertising his ignorance of science, as was made mind-numbingly obvious by his credulous acceptance of the JPANDS abortion-breast cancer “study” about five or six weeks ago. Brave iconoclast that he thinks himself to be, he’s getting that information out there, inspiring ignorant and credulous bloggers to link to him and spread the misinformation. He does women no favors and certainly does not promote a sober and science-based discussion of the real risks and benefits of the pill; instead he prefers to scare them with likely unfounded fears of breast cancer and defend “chastity balls” against “vile displays of hatred against Christians.”

Contrary to his apparent vision of himself as the brave warrior against “conventional wisdom,” Dennis Byrne is merely parroting an unremarkable meta-analysis that probably overestimates the risk of breast cancer due to the pill (if there even is a risk) that was published in a lower tier journal by an ideologue with an agenda regarding the topic as evidence of “suppression” of the science allegedly showing a link. All the while, he’s ignoring the full, scientifically supported risk-benefit profile of the pill and soft-pedaling the ideological bias of the study’s lead author. I suppose Byrne’s stepping up in the world, though. At least this new “ignored” study that he is citing in his quest to convince women that abortion and birth control cause breast cancer appeared in a peer-reviewed journal, rather than a politically motivated propaganda rag like JPANDS. Too bad his understanding of science remains stuck on stupid. Indeed, his supposedly self-deprecatingly labeling himself the “village quack” is an insult to quacks everywhere.

REFERENCE:

Kahlenborn C, Modugno F, Potter DM, Severs WB. Oral contraceptive use as a risk factor for premenopausal breast cancer: a meta-analysis. Mayo Clin Proc. 2006 Oct;81(10):1290-302.