An Associated Press article surprised owners of cats and other pets. A series of highly accredited research studies, conducted over the past decade, show that the same microchips used to track pets are the cause of rapidly growing malignant cancers in 1% to 10% of the laboratory animals tested. Now animal owners are faced with what to do.

Why do microchips cause cancer?

As Dr. Katherine Albrecht, a consumer educator and privacy advocate who helped investigate and reveal this story, explains, what scientists believe is happening is akin to a common splinter. When a splinter gets stuck in your finger, your body does everything it can to get rid of it. The site becomes red, swollen, and tries to dislodge the foreign object.

However, when a microchip is embedded deep in the fatty tissue of your cat or other pet, your body cannot push the chip out like a splinter. Instead, inflammation forms around the microchip. Scientists believe that these inflamed cells can turn malignant and then metastasize and move around the body. What’s worse is that these tumors can grow rapidly and be malignant.

What the research shows

Between 1996 and 2006, eight published veterinary and toxicology journals reported that laboratory mice and rats injected with microchips sometimes had a tendency to develop subcutaneous “sarcomas” or malignant tumors around implants. Below is a brief summary of some of the main findings.

• A 1998 study in Ridgefield, Connecticut of 177 mice reported that the incidence of cancer was slightly over 10 percent. The researchers described the results as “surprising.”
• A 2006 study in France detected tumors in 4.1 percent of 1,260 microchipped mice. This was one of six studies in which scientists did not set out to find microchip-induced cancer, but did notice the results incidentally.
• In 1997, a study in Germany found cancers in 1 percent of 4,279 mice with chips. The tumors “are clearly due to the implanted microchips,” the authors wrote.

What the researchers say

In researching the story, the Associated Press asked scientists to evaluate the available research. Specialists at some major cancer institutions said the findings raised red flags.

– “There is no way in the world, after reading this information, that one of those chips was implanted in my skin, or in one of my family members,” said Dr. Robert Benezra, director of the Genetics Program of Cancer Biology at Memorial Sloan-Kettering Cancer Center in New York.

–Dr. George Demetri, director of the Center for Sarcoma and Bone Oncology at the Dana-Farber Cancer Institute in Boston, agreed. Although the tumor incidents were “reasonably small,” in his view, the research underscored “certainly real risks” in RFID implants. In humans, sarcomas, which attack connective tissues, can range from highly curable to “tumors that are incredibly aggressive and can kill people in three to six months,” he said.

–At the Jackson Laboratory in Maine, a leader in mouse genetic research and cancer initiation, Dr. Oded Foreman, a forensic pathologist, also reviewed the studies at the AP’s request. He was skeptical at first, suggesting that the chemicals given to some of the studies could have caused the cancers and skewed the results. But he took a different view after seeing that control mice, which were given no chemicals, also developed cancers. “That could be a small indication that something real is happening here,” he said.

– “The transponders were the cause of the tumors,” said Keith Johnson, a retired toxicological pathologist, explaining in a telephone interview the findings of a 1996 study he conducted at the Dow Chemical Company in Midland, Michigan.

What can cat owners do?

1. Regularly check your cat or other microchipped pet for swelling or lumps, especially around the injection site. If owners or vets find anything abnormal in that area or any other area (as chips can migrate), an X-ray or biopsy should be done.
2. Dr. Albrecht also suggests that pet owners help her Volunteer to educate and connect with animal rights and animal advocacy groups, as well as veterinary organizations taking action on your website. Many of these animal-loving groups endorsed pets with microchips without having access to previous studies. Dr. Albrecht hopes that public pressure will also force Verichip Corporation, the manufacturer of the chip, to take responsibility or face a class action lawsuit.
3. Report any incidence of pets that have died of cancer or animals that have been cured of cancer to Dr. Albrecht in AntiChips, especially if the tumor is known or suspected to be or was linked to a microchip. This will help to better document the cancer test and avoid the use of microchips.

Sources: AntiChips.com; WashingtonPost.com