1st Case of Cancer in Naked Mole Rats Confirmed

by Laura Geggel, Staff Writer   |   February 17, 2016 02:48pm ET

Naked mole rats are renowned for their ability to live cancer-free, even when researchers try to induce the disease artificially.

Not anymore.

For the first time on record, researchers have diagnosed two naked mole rats (Heterocephalus glaber) with cancer.

"These cases represent the first formal reports of cancer in the naked mole rat, a rodent species best known for its extreme longevity and apparent resilience to typical health-span-limiting diseases, including cancer," the researchers wrote in the report, published online today (Feb. 17) in the journal Veterinary Pathology.

The finding isn't completely out of the blue. The researchers had previously followed a zoo-housed naked mole rat colony for 10 years, and found that some of the animals had precancerous lesions. But the new finding is still the first report of full-blown cancer in the critters, the researchers said.

In the first case, a 22-year-old male naked mole rat at the Brookfield Zoo in Chicago developed a mass on its upper right chest. The purple and red mass measured 0.6 inches (1.5 centimeters) in diameter. Researchers removed and studied the mass, and reported that it looked like an adenocarcinoma — a malignant tumor that likely started in the animal's mammary or salivary gland.

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