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Comment by warent | Hacker News Reader

A strange thought just occurred to me... they said that it was fertile with olives until it was destroyed by the fire. Plants grow and create fruit through cellular division, right? How is it possible for a plant to live for 2500 years without spontaneously developing a malignant mutation / cancer? Is it possible for plants to have cancer?

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Cancer isn’t even guaranteed in animals. Naked mole rats are notable for being mammals largely immune to tumors. They’re fascinating in other ways, especially their eusociality.

Cancer-like growths in trees exist, but they don’t have the problems with metastases animals do.

How have we observed enough naked mole rats to be confident of this? How did cancer rates in them become an object of study in the first place? Is there a reason to think they don't get cancer?

It’s not just naked mole rats. Some sharks, turtles, and other animals exhibit the same phenomenon. They’re not immune to cancer, but their defenses (mostly multiple layers of contact inhibition) prevent tumors from establishing themselves and metastasizing or growing to a dangerous size in their natural environment. The adaptations themselves tend to be mutation resistant so the probability that a cell will become malignant and lose those layers of protection is astronomical, whereas most animals have many single points of failure, so to speak.

Naked mole rats reportedly develop cancer when living in zoos where they are exposed to much more oxygen than they’re used to. Their genetics naturally prevent cancers when they’re living in a hypoxic underground environment but when exposed to the oxidative stresses of living above ground, the mutation rate can overcome their natural defenses

Right. But how did anyone come across this knowledge? Who would suspect that a particular creature might be better at fighting cancer than all the others?

Someone does a couple hundred necroscopies of dead individuals and finds no cancer deaths and decides to go digging, I suspect. There are captive colonies of the things, as they're more obviously interesting in a variety of ways.

Contact inhibition is among the most studied topics in biology due to its significance in cancer formation, aging, dermatology, etc. Scientists are always on the look out for species with interesting adaptations.

The general process goes: naturalists, zoologists, etc gather data on a species. Oncology/aging/whatever researcher notices a peculiar data point - in this case the naked mole rats' extreme longevity compared to other rodents - and investigates. The peculiar data points (lifespan, rate of cancer, etc.) percolate until someone stumbles on a plausible mechanism [1]. Rodents reproduce like crazy so it wouldn't take long to notice.

[1] https://www.pnas.org/content/106/46/19352

I’d encourage you to read https://en.wikipedia.org/wiki/Naked_mole-rat. They are awesomely bizarre creatures.

See also: "Why Blue Whales Don't Get Cancer - Peto's Paradox"

https://www.youtube.com/watch?v=1AElONvi9WQ

Plants can get tumors as a result of mutations.

However, they don't develop metastatic cancer because plant cells are not mobile as they are in animals. A malignant mutation won't spread. And they don't have central organs like hearts, lungs, etc. that can fail and kill the organism.

So, if your plant has cancer, you can just cut it off.

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