To recycle a comment:

> Oh, I agree, imagine a "grey goo" apocalypse, where uncontrolled and hyper-aggressive nanotechnology spreads everywhere in a unceasing orgy of consumption and replication. Mutating according to its own unknowable logic, it eventually it covers the land in an inhospitable blanket of massive crawling megastructures and inscrutable malign hive-minds!

> ... Oh, wait, that happened -- It's us. :P

This line of thinking about humans is exceptionally noxious when it gives a pass to AI or nanobots or anything other than human that might exhibit the real behavior that humans are hyperbolically accused of. That being said, the same logic applies: Evolutionary advantages lead to outcomes that don't get a fuck about what you or I want. So far, we have no examples of monocultural life gaining a permanent advantage over whatever evolves next, at least not on a geological scale. But my response to this is always some variation of: If you hate people so much, why do you have kids?

How do you know these "humanity is a virus" type of people have kids?

I never know that for sure, but it's a safe guess. It's become a bit of a hilarious trope here in Portland. The people who are always complaining about the rest of society's wanton disregard for the environment are the ones who aren't riding the bus. Their kids are the reason they're so worried about climate change, which is caused by overpopulation, you see. Nothing racist or Malthusian. They're shuttling their kids to soccer practice in a Subaru, how much more eco-conscious could they get? And when dad puts the kids down, he gets online and complains about how everyone else's consumption is ruining the world.

When you talk to other people who don't have kids, they always make sure to let you know they don't.

IMO, “Single cancer cell” isn’t really a the unit. Solid tumors act more like a mini organ with different types of cells having roles: driving blood supply, immune suppression, or enabling and executing metastasis are examples. Cancer isn’t sentient, but life finds a way. Fu*k cancer.

I am not an oncologist but I thought that metastasis was more related to a tumor growing too close to a major blood highway. If some of those cells that like to grow out of control get into that system they end up getting lodged all over the place. It seems less like "enabling and executing" and more like it just grows and grows until it leaks out. The ability for tumor cells to suppress the immune system however is fascinating. It's almost like an alien.

Cancers actually drive blood vessel growth into the tumors to feed themselves. I’m sure they leverage that as part of dissemination.

Different primary tumors (eg Prostate, breast, lung) have preferred sets of metastasis sites that are not always explained by where they get stuck due to getting into the blood supply. Even getting into the blood supply requires functions of degrading extra cellular matrix, evading immune surveillance, getting out of blood vessels and “setting up camp” at the news destination, and those requirements can be cancer and/or met site preferential.

Much of the immune suppression mechanisms are actually regulated systems normal cells use to prevent runaway inflammation. Cancer finds that function and highjacks it to “hide”. Conversely (to further illustrate complexity), some cancers use aspects inflammation as ”fuel” to drive tumor growth especially early in the cancer. I do agree- it is all truly fascinating.with that said: Fu*k cancer.

What I’ve never understood is how all this complex cooperative behavior emerges out of a relatively small number of mutations. I get that these are all repurposing of existing mechanisms, but still the overall coordination seems so much more purposeful than something that would happen with a few initial mutations and then some further selection. Particularly things like metastasis, which sounds like a many-stage process that would be hard to spontaneously evolve.

Yeah, it kind of makes you think that maybe some sort of cancer blob is the default state of cells and that everything that goes into making a collection of cells into a particular species is what's holding cancer back.

> but still the overall coordination seems so much more purposeful than something that would happen with a few initial mutations and then some further selection.

Isn't this just selection bias on a grand scale? You're looking at a specimen where the parts happened to end up arranged in a way that allows it to exhibit these properties that seem like coordination, while not paying much attention to the quintillions of specimens that did not.

It is more than just a few mutations. A good number of the common earlyish driver mutations are in the systems that detect and repair damage to DNA, which then accelerates mutation accumulation. (At some cost to stability of that lineage, but overall there are obliviously formulas that work)

And I’d also point out that these functions that are “sought after” by cancer are not all de novo, some things are complex functions that encoded for use by other normal cells at a other times and places in development of the organism. Some key mutations that enable the use of those functions by the cancer are crucial moments cancer development. Also many key mutations are loss of functions, which are often easier to accumulate. A example of genetic Losses of function is losing “contact inhibition” where normal cells stop growing when they get neighbors. Cancer cells loose this inhibition and just continue growing. This alone would require a suite of mutations. Another comment in the thread talks about cancer evolution and the good of the organism not making sense. Cancer doesn’t care about the organism. The organism has evolved many layers of checks and balances that can work for decades, but throw in time and poisons like smoking, UV damage, and there will be loopholes found. Cancer is persistent and has the entire genome of functions to turn on and off in various ways. Seriously Fu*k cancer.

Human body and immune cells and cancer cells all are complex. It is clear that for blind force , unconscious nature, and aimless chance could in no way interfere in such percipient, delicate art, and conscious subtle wisdom, and perfect providential balance; they could not be their work. It is impossible. It is also utterly impossible that living creatures made themselves for then each of their particles would have to possess comprehensive knowledge and wisdom like a god, to be able to know , see and make all the parts of their bodies and form it , indeed , it would have to know ,see , and make everything in the world connected to it.

"Whoever created the mosquito's eye ,created the sun. Whoever ordered the flea' stomach, ordered the solar system." from Quran's light

Many metastases spread through the lymphatic system, so more like the circulatory 'back roads' you might say.

That would imply that from a biological stand point it should have had a self serving purpose. But it kills the host. So what gives? Where is the logic?

It has the same purpose as us, just that while our "world" is the Earth (or whatever planet our species will conquer before extinction), its "world" is merely the human body it inhabits.

The death of a cancer's host body is like our equivalent of our star dying, and I guess our equivalent of interplanetary colonization would be a hypothetical cancer's ability to jump between hosts.

Neither humans nor any other known life-forms can meaningfully influence stellar evolution regards either the fate or timing of the Sun's end.

Cancer can and does bring about the death of its host.

(One might argue that both humans and other life forms have the potential and/or demonstrated capability to transform their own ecosystem beyond its viability to continue to sustain and support them, with both the present anthropogenic greenhouse-gas-based global warming and the Great Oxygenation Event and subsequent Snowball Earth serving as examples.)

That said, I understand your analogy.

There are virally- and clonally-transmitted or otherwise contagious cancers:

<https://en.wikipedia.org/wiki/Clonally_transmissible_cancer>

(These are rare and seldom found in humans.)

There are plenty of examples in nature of organisms and viruses that kill their host.

The thing with evolution is that it is random. So sometimes it really doesn’t make any logical sense.

Cancer colonies self-sustain and self-replicate, causing local success, then kill the host without escaping it, causing colony failure and do not successfully become a new species of independent pathogen. Local optimization causes disaster at a larger scale, causing the system to collapse.

Nothing intelligent is happening. Zero-foresight self-amplifying systems that will inevitably crash out will simply amplify themselves to that point, then cease. Applications to areas outside of oncology are an exercise for the reader.

This is why I think cancer is more like a lifeform than a chaotic pile of cells. Matt Levine demonstrated that applying certain electric field to a growing embryo alters its morphology without changing its dna, and since cancer is always in the rapid growth phase, it would be interesting to do a similar experiment on it.

There is a device the US FDA approved for brain tumors (Optune by Novocure)that uses alternating electrical fields. It surprised the field when it got approved as its mechanism wasn't conventional or well understood. There were also some confounding factors in the study design. That said, it's in a bunch of other tumor types now in more studies.