Junk sciencethe term has been bandied about a lot lately, especially in defense of silicone gel breast implants. But if you look beyond the headlines and sound bites, it's quite clear that implant apologistsnotably Marcia Angell, executive editor of the prestigious New England Journal of Medicineare guilty of the very sin they accuse implant critics of: junk science.
Recall that in several high-profile lawsuits, women have won multimillion-dollar damage awards from implant makers by persuading juries that the gelatinous devices cause debilitating arthritis-like conditions, known as connective tissue diseases, and that implant maker Dow Corning Corp. fraudulently marketed the products despite prior knowledge of potential side effects from the devices. In 1992, safety concerns led the Food and Drug Administration to set severe restrictions on the use of silicone gel implants. The media ran stories sympathetic to implant plaintiffs, and in 1994, Dow Corning offered to establish a $4.2 billion fund to compensate women who could demonstrate harm from the devices. The implant debacle looked like a clear victory for tens of thousands of female Davids over a corporate Goliath.
Then suddenly, the media pendulum swung the other way, depicting implants and their makers as the unfortunate victims of greedy women and attack-dog lawyers. A 1994 study published in the NEJM by researchers at the Mayo Clinic compared the medical records of 1,498 women without implants residing in Olmsted County, Minnesota, where Mayo is located, with those of 749 age-matched women who'd received implants at the clinic from 1964 through 1991. The researchers found "no association between breast implants and the connective tissue diseases that were studied."
In an accompanying editorial, Angell praised the study as meticulous"well-designed
the best data we have." She subsequently became the chief apologist for implants. Her 1996 book, Science on Trial, portrays Dow Corning as a near-innocent raped by scurrilous plaintiffs and lawyers. And just a few months ago, she reiterated her implant defense: "We can say with reasonable confidence
that any link between implants and a variety of systemic diseases and symptoms is very small, if it exists at all."
The impact has been significant: In current settlement discussions, Dow Corning (now in Chapter 11 bankruptcy) is offering $2.4 billion$1.8 billion less than the 1994 offer.
But the study Angell touts as "the best data we have" is a case of junk science. In epidemiology, the larger the number of people studied, the more reliable the results. The Mayo group of 749 implant recipients sounds large, but the connective tissue diseases linked to implants are rather rare. To detect them with any reliability would require a much larger group than the Mayo sample. In the words of the Mayo researchers themselves: "We had limited power to detect an increased risk of rare connective tissue diseases." They calculated that to detect any significant increase in risk would require a sample of "62,000 women with implants and 124,000 without them"83 times more implant recipients than they studied.
In addition, the Mayo researchers paid attention only to classic symptoms of connective tissue diseases (rheumatic conditions associated with lupus, rheumatoid arthritis, and scleroderma) and ignored unusual symptoms that other
studies have linked to silicone gel exposure. Other studies vindicating implants have similar flaws, according to an exhaustive 1996 FDA review published in the Annals of Internal Medicine, which concluded that "no implant study has ruled out
increased risk of connective tissue disease."
Why would the NEJM and other journals publish flawed research? Some may suggest darkly that pressure from the drug and medical device industriesheavy funders of medical research and the major advertisers in medical journalsplayed a role. Perhaps. But in all likelihood, there's a simpler answer: Gathering truly definitive data based on a huge sample of women with implants is financially and logistically impossible. Researchers submit fair-to-poor data because that's the best they can do. The journals bury the researchers' own qualifications deep in the report, and these qualifications rarely make it into the mainstream press. The press, it seems, believes that when it comes to hot-button medical issues, any study is better than none, even if the results are misleading. Bad data can be the "best" data if that's all that's available.
Despite the clear flaws in the studies she cites, Angell insists that any apparent connection between implants and connective-tissue diseases is coincidental. "Remember, about 1 percent of women have implants, and another 1 percent have some form of connective tissue disease. Therefore, about 10,000 adult women in this country have bothjust by coincidence," she wrote in April 1996.
She would be making a good pointif only 10,000 women claimed connective tissue symptoms from implants. But more than 300,000 women have filed claims against implant makersat least 50,000 of which involve symptoms of connective tissue disease. And since the early 1960s, when implants were first introduced, dozens of medical journal reports have documented strange connective tissue symptoms in women with the devices. If these reports are to be believed, connective tissue problems affect well over the 10,000 women who might develop them by chance.
Recently, Harvard researchers surveyed 395,000 women in their ongoing Women's Health Cohort Study, 10,830 of whom had received breast implants from 1962 to 1991. This is by far the largest implant study to date, though it falls well short of the 62,000 recipients the Mayo researchers calculated would be necessary to answer the connective-tissue-disease question once and for all. This study has its flawsnotably that it relies on self-reported casesbut the sample is still 14 times larger than the Mayo's and more able to show a link to connective tissue diseases. And it didrevealing a 24 percent increase in the incidence of lupus, scleroderma, rheumatoid arthritis, etc., among the women who had implants. This increase is small by statistical standards, but the real figure could be higher because, like the other researchers, this group looked only for the classic illnesses, not the atypical connective tissue symptoms many women with implants have reported.
Meanwhile, the attention given to connective tissue diseases has obscured from public discussion the other seriousand indisputableproblems caused by implants. They are clearly prone to rupture, in some cases sending gobs of silicone gel coursing around women's bodies. Dow Corning claimed its implants would "last a lifetime." But according to the 1996 FDA review, one-third to one-half of implants rupture or leak silicone gel within 10 years; after 10 years, the number increases to between 64 and 96 percent.
Even if they don't fall apart, implants often cause painful hardening of the tissue around the device (capsular contraction) and other local problems, including breast infection, chronic breast pain, and destruction of nipple tissue. Last March, the Mayo Clinic team released a report showing that its 749 implant recipients "frequently experienced local complications," chief among them capsular contraction, with 24 percent of the women requiring additional surgery to replace ruptured implants and correct other problems. There are no medical disputes surrounding these complicationsand thus no media attention.
And while implants have never been linked to breast cancer, they interfere with mammography, limiting cancer detection. According to the FDA review, implants obscure 25 to 35 percent of breast tissue. Don't believe the implant apologists. Silicone gel breast implants are dirty.