A rare form of contagious genital cancer that only affects dogs have been traced back more than 10,000 years, according to new research, reported by The Los Angeles Times.
A new study published in the journal Science reveals that canine transmissible venereal tumor (CTVT) - one of the only two known contagious cancers - is the oldest and most widely spread cancer. Researchers say the disease may have arose in an Alaskan malamute or husky-type dog about 11,000 years ago, The Los Angeles Times reported.
"The genome of this remarkable long-lived cancer has demonstrated that, given the right conditions, cancers can continue to survive for more than 10,000 years despite the accumulation of millions of mutations", Elizabeth Murchison, first author from the Wellcome Trust Sanger Institute and the University of Cambridge, said in a statement.
In an effort to find out how the cancer lasted so long, researchers investigated "how the disease managed to escape the original host and then each subsequent host thereafter," Medical Daily reported. Researchers said they believe the cancer survived by the transfer of its cancer cells to other dogs during mating.
Transmissible dog cancer is a common disease found in dogs around the world today. The genome sequence has helped scientists to further understand how this disease has spread.
"The patterns of genetic variants in tumors from different continents suggested that the cancer existed in one isolated population of dogs for most of its history," Elizabeth Murchison, first author from the Wellcome Trust Sanger Institute and the University of Cambridge, said in a statement. "It spread around the world within the last 500 years, possibly carried by dogs accompanying seafarers on their global explorations during the dawn of the age of exploration."
Researchers said that apart from the dog transmissible cancer, the only other known naturally occurring transmissible cancer is an aggressive facial cancer in Tasmanian devils that is spread by biting.
