Why Don’t Whales Get Cancer?

bowhead whales Balaena mysticetus

A juxtaposition unfolds within the animal kingdom, where certain species consistently sidestep the clutches of cancer, while others, like dogs and cats, find it emerging as a predominant cause of demise. Remarkably, certain creatures, such as antelopes and sheep, largely remain untouched by the cancer scourge, while others, like foxes and leopards, are predisposed to its development. Notably, bats revel in a shielded existence, whereas mice and rats face a different fate.

Scientists from the Wellcome Sanger Institute in Cambridge, England, have delved deeply into this mystery. Their research has significant implications, as The Guardian highlighted. The revelations gleaned from their endeavors possess the potential to elevate the caliber of cancer screening in humans, ushering in enhanced diagnostic precision. Moreover, these insights could chart a course toward more refined and effective treatments, casting a hopeful light on the pursuit of ameliorating the impact of cancer on human lives.

The impact of cancer on human life is undeniable, with approximately 18 million people affected and 10 million dying each year. What renders this even more astonishing is the paradox that emerges when scrutinizing the animal kingdom: many majestic beings—like whales and elephants—manage to elude the clutches of cancer, defying the odds stacked against them. Given their expansive cellular landscapes, one might intuitively assume that these creatures are more susceptible to tumorous growth, with each cell potentially triggering a malignant transformation.

Intriguingly, this assumption is met with a remarkable contradiction. Take, for instance, the grandeur of whales. With a cellular count dwarfing that of humans by a factor of a thousand, these oceanic giants should theoretically face a corresponding thousand-fold increase in their vulnerability to cancer. Yet, in stark defiance of this logic, bowhead whales traverse their existence, boasting lifespans that can stretch to 200 years.

The impact of cancer on human life is undeniable, with approximately 18 million people affected and 10 million dying each year. What renders this even more astonishing is the paradox that emerges when scrutinizing the animal kingdom: many majestic beings—like whales and elephants—manage to elude the clutches of cancer, defying the odds stacked against them. Given their expansive cellular landscapes, one might intuitively assume that these creatures are more susceptible to tumorous growth, with each cell potentially triggering a malignant transformation.

Intriguingly, this assumption is met with a remarkable contradiction. Take, for instance, the grandeur of whales. With a cellular count dwarfing that of humans by a factor of a thousand, these oceanic giants should theoretically face a corresponding thousand-fold increase in their vulnerability to cancer. Yet, in stark defiance of this logic, bowhead whales traverse their existence, boasting lifespans that can stretch to 200 years.

This perplexing decoupling of cell count and cancer risk is encapsulated within the confines of Peto’s paradox. This paradox underscores the capacity of certain species to thwart the perils of cancer, despite possessing cellular landscapes that ostensibly should elevate their vulnerability.

Goodbye to Lab Mouse?

In order to address this enigma, researchers at the Wellcome Sanger Institute conducted an examination of the genetic material belonging to creatures that perished due to inherent circumstances. The subjects of this analysis encompassed a variety of species, including ferrets, lions, tigers, giraffes, ring-tailed lemurs, and naked mole rats. Notably, the naked mole rats, diminutive in size akin to a mouse and boasting a longevity of approximately three decades, exhibit infrequent instances of cancer manifestation. Alex Cagan, the head of this endeavor, likened these creatures to “cocktail sausages with teeth,” shedding light on their distinctive attributes.

The scientists collected and studied cells from the intestinal gland, which provides a good way to compare genomes. “We used them to count the numbers of mutations each species was accumulating every year,” explains Alex Cagan. “What we found was very striking. The number of mutations each was accumulating every year varied enormously. Essentially, long-lived species were found to be accumulating mutations at a slower rate while short-lived species did so at a faster rate. In addition, it was found that, at the end of a lifespan, all the different animals that were studied had amassed around 3,200 mutations.

Nevertheless, the research team has not yet ascertained the precise mechanism through which animals with extended lifespans effectively reduce their DNA mutation rates. Furthermore, this correlation has currently been established solely among mammal species with relatively moderate lifespans. Consequently, researchers now aim to extend their investigation to encompass plants, insects, and reptiles.

The culmination of this research journey presents a thought-provoking proposition: the ubiquitous laboratory mouse, a staple in cancer experiments, might not stand as the optimal mammalian model for analysis. Alex Cagan states, “Now we can think about looking at much longer-living species that may be more relevant and be useful models for understanding cancer resistance.

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