I detest articles that use the word "cure" and "cancer" in the title. They are without fail so breathless about the clichéd achievement that they are exploiting in the headline that they either fail to acknowledge the real magnitude of the problem or gloss over it with practiced sleaze (not sure which happened to the writers here).

We've had a "cure" for cancer since the times when barbers also performed surgery on the side (Egyptian civilization, at least), and that is surgical excision. It's still the best treatment we have for many cancers, e.g. melanoma and lung cancer, both of which are much more common than the cancer in the article. It doesn't work for every cancer, but for some cancers it works good enough, and even better when combined with chemotherapy (which ham-handedly slows replication in every cell in your body). The point of any cure is to remove the cancer cells from your body and for some cancers they fortunately stay within one excisable area.

Like the GP comment pointed out, this is essentially a much more targeted version of the same thing. Obviously it would be better for the patient to retain B cells, without which they will have no adaptive immunity--just like a patient with melanoma would prefer to keep the hunk of their nose that the surgeon had to remove. This is an incremental, very fancy and very expensive improvement on the same old strategy of killing the organ to save the body. It will never work on non-blood cancers (which are the vast majority of cancers, BTW).

People do not understand that cancer is a disease that combines the trickiest parts of fighting aging with the trickiest parts of fighting infectious disease. Cell replication is one of the hardest things your body has to do, and it does it several trillions of times per day in your body, essentially copying about 1 billion TB worth of data while automatically detecting and fixing every dangerous error that could possibly result. It is natural that this process will screw up catastrophically at some point--on an infinite timescale, assuming we fix all other health issues, everybody will still get cancer just as surely as they age every year. And once they do, you have a cell that your immune system has carefully trained for decades not to engage, invading and hogging every resource it can, with mutations that allow it to adapt to selective pressures, including any drugs you might throw at it. Essentially, it's an infectious parasite, except it looks 99% like your own cells to your immune system, and is already perfectly suited to your body's style of metabolism.

Let's keep in mind that this can arise from any cell in your body that replicates, and just about every organ system has a good number of those to replenish malfunctioning or old cells and fix injuries. The possibilities are staggering and so are the number of known cancers.

There is no "magic bullet" that cures every single cancer, just like there is no "magic antibiotic" that kills every infectious bacterium. Even the smartest, most generalizable ideas right now, like cancer vaccines, depend on your immune system to make the final push, and the immune system is just as fallible as any other organ system. At the point where somebody can make the claim that all cancer is cured, we will as a matter of course have gained control over every replication event that occurs in our body (trillions upon trillions of nanoscale events per day). That will be a truly remarkable feat, but is in no way within reach of any foreseeable technology.

When we cure cancer, we will have by necessity cured aging and all infectious disease will have become a relatively trivial problem. That should put the claim of "curing cancer" into perspective.

I'm still waiting for the nanobots that we were promised two decades ago.

Imagine a billion nanobots swarming inside your body, networked [1] and analyzing every cell they come across. Over time, they build a gigantic database of your cells. Then they'll be able to use some heuristics to determine whether any given cell is a menace to your health. If it is, they either tag it for apoptosis or terminate it with a micro laser, depending on how reliable they think each method would be.

Movie material today, reality tomorrow. When this happens, I'll finally welcome the combination of "cure" and "cancer" in the same sentence.

[1] https://xkcd.com/865/

You've basically described the immune system!

The immune system is imperfect, but it's a lot more complicated than any man-made system so far. Trillions of cells, thousands of genes controlling each one, hypermutations creating billions of different antibodies, slipping into and out of each corner of the body. Basically, organized chaos; by some measures, more complicated than the brain.

I would welcome potential designs for an auxiliary system, but what we have already is hard to understand, much less supplant. Certainly the concept of retraining the immune system is appealing, and looking beyond the OP's microbead/reinfusion rigamarole, we've already been doing that for decades via vaccines.

And considering that there are no laws of nature that prohibit redundant replication of data with virtually no errors there should be no limit to improvement in that area.

There most certainly are, at the information density of DNA. DNA is about a thousand times more information dense than our best hard drives. At that level, a passing photon can change or break enough chemical bonds to alter the bits. A nearby high-energy molecule can do the same. This actually happens gazillions of times per day in our body and we have a few hundred enzymes to automatically correct errors and a few hundred more to detect when those can't fix the problem and shut down the cell. The fact that it works at all is jaw-droppingly amazing. We take copying bits on and off hard drives for granted, and they only work for a few years max--cells operate on an entirely different scale of information transfer and yet some multicellular organisms live for centuries.

Unfortunately, I don't think you could improve the error checking mechanisms in our cells without fundamentally redesigning a lot of how we work. It would be interesting to try to add more "parity" mechanisms besides the complementary base pairing, which is used by most of the repair enzymes. From an evolutionary standpoint, no species would ever naturally develop perfect DNA replication because it would halt diversification, which is needed to survive continually changing environmental threats.

I should also add that it's a misconception that every cell in our body has the exact same DNA. That's only a half-decent approximation. In reality, a lot of our cells accumulate trivial mutations and it's OK. Some cells even rely on editing their own DNA to perform their primary function: that includes the B and T cells [1] which the cancer in the OP arise from.

[1]: http://en.wikipedia.org/wiki/VDJ_recombination

My gut feeling is that the final cure for cancer (and by extension aging and other diseases) will come about through a much simpler mechanism (more basic I mean, not easier), more in line with engineering than medicine. They’ll need to be able to systematically map any type of cell in the body and trigger its death, then insert a replacement cell at that site or coerce the body into doing it. It may not be possible with just our immune systems because it’s an area that evolution overlooked and we just don’t have the genes and cellular machinery for it.

I’m really skeptical that we’ll have nanobots to do that anytime in the foreseeable future, but, there are tons of other options like engineered viruses or chromosomes that don’t seem nearly as far-fetched. If we forget about medicine for a moment and just think about the fact that the compressed human genome fits on a CD, then the mutations in a cancer cell are going to be much smaller than that, potentially small enough that they can be encoded as something akin to lisp programs. They could find markers from a cancer cell in the lab, and then evolve genes to recognize them and tag or kill the cells with genetic algorithms in a computer. When we hear about engineered viruses killing the people they were meant to treat, I think that happens because humans just can’t program something like that manually. It has to be evolved over generations to take into account countless factors that might not occur to us.

To me, that kind of simulation is straightforward. It’s just another big data problem, and we need better sequencing so that patients can get loaded into a computer cheaply. Once a solution has been evolved with a high degree of certainty (like thousands of times the confidence level of anything today), and has a reliable cutoff switch, then synthesizing that becomes “just an engineering problem”.

TL;DR: We need github for medicine so that all of the tools in the arsenal can be recruited as external libraries and simulations can be run in a distributed fashion by hackers who handily find solutions to any problem that’s thrown at them but can’t be bothered to obtain medical degrees.

Once cure exists - the real cure, meaning no single cell is left from original cancer that survived the latest 'cure' to then pass its genes to its progeny (which is maybe impossible, who can say) - there is no risk to adaptation to the cure.

Now, I can imagine scenarios when this would not hold - for instance vertical genetic transfer to different hosts via some infectious vector but that is probably highly improbable.

First of all, this hypothesis is still highly contested in the literature. There are no doubt certain pathways (usually part of cell cycle regulation) that happen to be used by most cancers, but there are hundreds of genes involved in the cell cycle and we aren't even close to enumerating all the ways that it can malfunction. The fact that most cancers use similar pathways is no doubt reflective of the fact that they are the easiest pathways toward malignancy, not the only pathways.

Secondly, say we do take the top N common mechanisms and create a bulletproof inhibitor. Now your statement about convergent evolution is no longer true. Anything that kills cancer cells (excision, radiation, chemotherapy, something targeted) exerts selective pressure, and you will instead start seeing cancers that utilize the (N+1)th easiest pathway, (N+2)th, and so on. It's like trying to stop all the ways that a car could break down: possible up to a certain point, impossible in the long run.

I also contest the statement that "you are basically reverting its evolution to day 0". Germline predispositions for cancer are an important part of the disease and not selected against in a society where people have natural-born kids between 20 and 40. If there were a cure for cancer, it would probably involve genetically engineering humans that are extremely unlikely to get it (and also age very slowly, etc.). But then you are looking at a totally different kind of society.

> genetic transfer to different hosts via some infectious vector but that is probably highly improbable

This is not only probable, it is known (so far, 12% of human cancers). Viruses linked directly to cancer include HPV, EBV, HTLV, and polyomavirus [1]. A virus that causes cancer can be a very successful virus, depending on how long the infectious/replicative phase is compared to the symptomatic phase. Replicating infected host cells = more viral production = greater likelihood of survival and transmission.

There are some researchers that think that all cancer is caused by viruses that have yet to be identified. I don't think that's literally true, but we can find all kinds of remnants of ancient viruses in our genome, so in a way, they might be on to something.

[1]: http://en.wikipedia.org/wiki/Oncovirus

You have no idea what those words mean.

This.

People need to stop thinking cancer as a single disease, but as a constellation of disease. Just like you cannot "cure" the Internet from computer viruses with a magic program, you cannot cure cancer in with an unique solution.