One of the greatest mysteries in the medical world is why whales, the largest mammals on earth, don’t seem to get cancer as often as humans and other animals. Despite their size and long lifespans, whales have a notably low cancer rate compared to other species. Researchers have been baffled by this fact for years, but recent studies and data are finally shedding light on this enigma. In this article, we will explore the potential mechanisms behind whales’ cancer resistance and what this could mean for cancer research and treatment.
Cancer is a leading cause of death in humans, killing around 10 million people every year. However, scientists have discovered some species that avoid getting cancer, while others are plagued by tumours that shorten their lives. For example, whales tend to have low rates of cancer, but it is the leading cause of death for dogs and cats. Foxes and leopards are susceptible, while sheep and antelopes are not. Even more surprising is the fact that many huge creatures, including whales and elephants, generally avoid cancer, even though they possess vast numbers of cells, each of which could trigger a tumour. This is known as Peto’s paradox, named after the UK statistician Richard Peto who first outlined it.
Scientists at the Wellcome Sanger Institute, in Cambridge, are investigating Peto’s paradox in collaboration with researchers from a number of centres, including the Zoological Society of London (ZSL). The team studied a range of animals that had died of natural causes at London Zoo, including lions, tigers, giraffes, ferrets, and ring-tailed lemurs. In addition, naked mole rats from a different centre were included in the study. The scientists then isolated cells known as intestinal crypt cells from each newly expired animal and studied their genomes. By comparing the genomes, the team was able to count the number of mutations each species was accumulating every year.
The team found that long-lived species like elephants and whales accumulated mutations at a slower rate compared to short-lived species like mice. For example, in humans, we get about 47 mutations a year, while in mice, it is around 800 mutations a year. In addition, the team found that at the end of their lifespan, all the different animals that were studied had amassed around 3,200 mutations. However, exactly how long-living animals successfully slow down their rate of DNA mutations is unclear. The link between mutation rates and lifespan has only been established for animals that have a low-to-middle lifespan. Therefore, extending the study to plants, insects, and reptiles could provide more insight into the relationship between mutation rates and lifespan.
Cancer is a disease that occurs when a cell in the body undergoes a series of mutations in its DNA and begins to divide uncontrollably, and the body’s defences fail to stop this growth. The more cells that an animal possesses, the greater the risk of one becoming cancerous. From this perspective, it is puzzling that many huge creatures avoid getting cancer. However, understanding Peto’s paradox offers new insights into cancer screening and treatment, as well as the ageing process. Scientists suggest that by studying longer-living species that offer a better model for understanding cancer resistance, we could develop improved cancer treatments that might moderate the worst impacts of ageing.
In conclusion, the mystery surrounding why whales don’t get cancer could lead to new breakthroughs in the world of cancer research. As humans continue to struggle with the disease, studying these majestic creatures could provide important insights into the mechanisms of cancer and how to combat it. While there is still much to learn about the topic, the fact that whales have evolved unique biological processes to prevent cancer is nothing short of remarkable. The intricacies of the whale’s biology may hold the key to unlock one of the greatest mysteries in medicine, and it is exciting to think about the potential discoveries that may await us. By understanding the fascinating world of whales and their incredible physiology, we may just be able to make significant strides in the battle against cancer.
