Women as guinea pigs: tungsten in breast bancer patients


By Diana Zuckerman, Ph.D.
Updated 2011

A medical device that was never tested in human studies has been recalled because it left hundreds of tungsten particles in the breasts of women being treated for breast cancer. See Riddled With Metal by Mistake in The New York Times.

The Axxent FlexiShield Mini, made of silicone and tungsten, was intended to protect healthy breast tissue from radiation during a new radiation technique for women undergoing lumpectomies to treat breast cancer.

Rather than requiring clinical trials and inspections, as is done for prescription drugs and less than 5% of medical devices, the FDA allowed the shield to be sold after reviewing it through the less stringent 510(k) process.  FDA spokesperson Karen Riley referred to this decision as appropriate in order to avoid “reinventing the wheel” for devices that are similar to those already on the market.  The shield was deemed by the FDA as “substantially equivalent” to an older shield made with lead; the new shield is made with tungsten and silicone, and left hundreds of tiny tungsten particles in the women’s breasts.

No one knows the health risks of tungsten in breasts, but at the very least, the particles interfere with the accuracy of mammograms because they show up on mammograms as white specks, which look just like small specks of cancer.  If the doctor assumes the specks are tungsten, not cancer, the women could have undiagnosed and untreated cancer, which could be deadly.  If the doctor assumes the specks are cancer, but they are actually tungsten, the women will have surgery that is not necessary.

This is a great example of why potentially dangerous medical devices should be subject to clinical trials and inspections (Medical Device Recalls and the FDA Approval Process).  Without those safeguards, it can take years to discover that a device is defective; meanwhile, thousands of patients can be harmed.  The tungsten problem was noticed quickly only because the patients were participating in a clinical trial of a new radiation technique-there were no clinical trials of the tungsten device.   Because the women were in a study of the radiation technique, the doctors did a 6-month follow-up with mammograms for all their patients, and that’s when they discovered the tungsten particles in the women’s breasts.

What if the women hadn’t been in that study?  The tungsten shield was cleared by the FDA in June 2009, and when we checked on March 21, 2011, there was only one report of the tungsten particles on the public reporting system for medical device defects.  That report referred to four different patients with tungsten particles in their breasts, and was made by an unnamed nurse in June 2010 but not “received” by the FDA until January 2011. We don’t know what the delay was in reporting, but we know that more than four patients have already been diagnosed as having tungsten particles in their breasts due to the shield.  If the patients hadn’t been participating in a clinical trial of the new radiation technique, it could easily have taken many additional years before health professionals reported the problem for so many patients that the FDA noticed the reports.  FDA receives too many reports of medical device serious adverse reactions to study all of them so it can take a long time to come to their attention.

The breast cancer patients who had been exposed to the tungsten shield had undergone lumpectomies.  The surgeon therefore had removed the cancer but not the women’s breasts.  Now, a year later, those same women must consider mastectomies to rid their bodies of tungsten, not cancer–a problem that would not have happened if the device had been carefully tested in either animals or humans, and the manufacturing plant had been inspected, before the device was sold.

This is an example of what happens when FDA allows medical devices to be sold without solid scientific evidence.  When a medical device could cause this kind of damage, it should be carefully tested first to make sure it is safe before thousands of patients use it.  Before studying it on even one woman, the shield could have been tested on animals or perhaps in excised tissue.  Instead, patients paid for this dangerous device without it ever being tested-even on them.