Medical Device Daily Washington Editor

A recent Associated Press article on the radio frequency identification (RFID) device manufactured by VeriChip (Delray Beach, Florida) has triggered a reaction in the media about both privacy and health considerations. According to one expert, however, the health concerns are an overreaction to the incidence of sarcomas in four cats and dogs out of roughly 12 million pets that have been implanted with the chip.

Whether such reassurances are enough to assuage public fear remains to be seen, but the company’s shares have been adversely affected, losing more than $1 a share, about one-fifth of the stock’s value, in volatile trading on the NASDAQ board over the past three days.

The AP article, which made the wires this past Sunday, attempted to tie former Secretary of Health and Human Services, Tommy Thompson, to the matter. The article points out that Thompson headed HHS at the time of the device’s approval and that within two week’s of the FDA approval, “Thompson left his post, and within five months was a board member of VeriChip” and its parent company, Applied Digital Solutions (Delray Beach, Florida).

The AP article says that Thompson was “compensated in cash and stock options,” but gives no indication that Thompson was alleged to have interfered in the approval process for the VeriChip.

The popularity of the VeriChip is mainly among pet owners who have had the device implanted so that their lost dogs and cats could be identified and sent home rather than euthanized if unclaimed. By some accounts, veterinarians are now being deluged with requests to have the chips removed, and the reaction to human use is likely to be even more aggressive.

The chip’s supporters would argue that in the proposed human uses, the chip’s benefits overshadow its risks. Much of the interest for human use is for those with cognitive disorders, such as Alzheimer’s, at risk for wandering off and getting lost.

An article appearing in the American Journal of Public Health in 1998 said that slightly more than 2.3 million Americans were afflicted with Alzheimer’s in the previous year, but the authors predicted that the prevalence “will nearly quadruple in the next 50 years, by which time approximately one in 45” people in the U.S. will have the disease. Assuming the population of the U.S. is 400 million in 2048, this would come to almost 9 million (the U.S. Census Bureau projects a U.S. population of 419 million in 2050).

Other uses of the VeriChip in humans would include patients with other dementias and patients whose conditions make them unusually at risk for complications when injured or ill. The company also advertises the VeriChip for use in maternity wards as a means of preventing accidental or deliberate child swap, which is said to occur as often as 20,000 times each year, leaving 40,000 children in the wrong homes. VeriChip derived this latter figure from the June 2003 edition of the Journal of Healthcare Protection Management, and this use would presumably involve only temporary use of the chip.

Several prominent physicians have weighed in on the issue. Robert Benezra, MD, the head of the cancer biology genetics program at the Memorial Sloan-Kettering Cancer Center (New York), told the AP.

“There’s no way in the world, having read this information, that I would have one of those chips implanted in my skin, or in one of my family members.”

Despite the flurry of negative comments, Scott Silverman, the firm’s CEO, said that the AP article “and the alleged research cited [in the article] make no link whatsoever to malignant tumor formation in dogs and cats but for one unsubstantiated report” and that “over the past 15 years, millions of dogs and cats have safely received an implantable microchip with limited or no reports of adverse health reactions.”

Lawrence McGill, DVM, a veterinary pathologist at Animal Reference Pathology (Salt Lake City), told Medical Device Daily that the incidence of tumors in lab mice and rats is not conspicuous since these animals are genetically predisposed to express tumors as compared to their counterparts in the wild. McGill also said that the studies cited by opponents of RFID implantation included no controls, and hence lacked comparisons to a normal incidence in the same population.

McGill said that epidemiological evaluations “have noted no association with microchips,” and that some of the fear-provoking data comes from “veterinary diagnostic labs that combined data for sarcomas with other data on other types of tumors.” McGill added that a needle and syringe also constitute a risk factor for lab rodents.

“Most pathologists agree that injection sites have their own” risk profile for sarcoma formation, he said.

“Veterinarians found many years ago that when cats got into fights, many of those cats had sarcomas in their eyes” when their opponents landed a claw in the eye, he said, adding that he and many others have “never seen what we thought was a microchip-only” source for a sarcoma. However, he recommended that veterinarians implant the Verichip in a site other than the site for an injection.

He said that even if the incidence of sarcoma formation in animals holds up in humans, “if you put a chip in someone’s Alzheimer’s mother,” that patient is likely to pass away before he or she will react to the chip. This difference in the rate of tumor acquisition is predicated on a difference in the metabolic rates of rodents and humans. “One year in the rat’s life equals about twelve or more” in humans, he said, adding that the lifespan ratio is roughly paralleled by the comparative rates of tumor formation. McGill also said that this is not a speculative line of thinking.

“There is data that says mice and rats acquire tumors much more quickly than humans,” he said

McGill was wary about the possibility of widespread use of implanted chips, however. “I think we’re going to where our kids might be microchipped one day,” he said, adding that he is not keen on the idea unless there is some compelling reason. However, for someone who suffers from recurrent bouts of amnesia, “I’d put one in him in a heartbeat,” he said. As for patients with Alzheimer’s, who are prone to leave the house and get lost, “I’d put a chip in them even if they were 50.”

At press time yesterday, VeriChip stock was trading at $4.64, down 24 cents from its opening price.