Cancer affects some animals with the same effect as in human beings, and could be the cause of extinction of some wild species. The researchers say the Society of Preservation of Fauna and Flora of New York have found an increase in cancer cases in wild animals in recent years.
According to their findings, published in Nature Reviews Cancer, the species most affected are those at risk of extinction, like the Tasmanian devil, a small marsupial carnivore, already decimated in the late nineties by a rare form of transmissible cancer (the devil facial tumor).
The cause is unknown, but it has been shown that malignant cells are able to spread among the samples and through bites during fights. To save the species, biologists are now isolating infected animals in zoos or reserves.
Denise McAloose and Alisa Newton, authors of the study, have investigated the possible causes of cancer in different species, and have found a correlation between cancer and pollution. For example, for the living beluga in the estuary of the St. Lawrence River (Canada), a form of bowel cancer is the second leading cause of death. The culprit could be an organic compound (a polycyclic aromatic hydrocarbon that is found in oil, but also in municipal waste), already known to be carcinogenic for our species.
In this case, the researchers report, it is clearly the responsibility of human beings. Other animals, however, are affected by cancer to the genital organs caused by viruses. Among these, especially the sea lions in the seas of California and dolphins along the coast of South America, while green turtles are infected with a virus that causes fibropapillomatosi.