4 ms·
"We've seen this before in science, with antibiotics. A few major, early wins followed by the long silence of failure, due to second-order adaptation by cells."
by emiliobumachar 13y ago
"We've seen this before in science, with antibiotics. A few major, early wins followed by the long silence of failure, due to second-order adaptation by cells."
But the key difference is that cancer does not pass from person to person, unlike bacteria. All cancer cells die before or with the patient, they don't stick around to "remember" how to defeat the hack.
If we do get some major, early wins, they are likely to be very reproducible, indefinitely.
- dekhn 13y agoTumor cells form populations; within the person, there are many generations of expansion and adaptation. Within that time, they definitely "remember" how to defeat the hack.
- cLeEOGPw 13y agoYes, but other people are unaffected by that one person. That doesn't mean 100 percent chance of cure, but the chance remains the same for every person.
- dekhn 13y agoyou're just pointing out a minor difference in my analogy. in cancer, the "population" is the tumor cells in a single human's body, while with bacteria, the "population" includes invading cells that infect multiple people and carry resistance between them. In both cases, the dividing cells propagate their inherited traits that allow them to evade the immune system or treatment. When you treat a person with a cancer drug, the cancer tumor population evolves (selection and natural variation), when you treat a population with an antibiotic, the bacterial population evolves. That was the point of my analogy.
- emiliobumachar 13y agoThe analogy is valid, but the difference is not minor. With infectious disease, if there are ten possible mutations to make the pathogen resistant to treatment, each with a 1% chance of happening within the course of the disease in one patient, then pretty soon all mutations would be present in most of the whole pathogen population on Earth, because of natural selection. With non-infectious diseases such as cancer, in the same scenario, there would be about a 10% chance of the cancer cells developing one or more of the mutations in each patient, period. A tragedy for those 10% of patients, but a cure for the other 90%.
- dekhn 13y agoyou're missing the point. cancer is internally infectious. Primary tumors don't even really kill people that much- patients almost always die from metastases. These metastases typically are more resistant. Please read the entire book "Molecular Biology of Cancer". I'm just explaining small parts of it.
- scribu 13y agoI guess the question then becomes: can the cancer cell population in a single patient evolve fast enough to evade the newly improved immune system, before it gets killed off completely?
- dekhn 13y agoIt seems unlikely. The genetic diversity was already created. Even when people report "we cannot detect any cancer cells in this person's body, so they're cured", they aren't saying there are no repositories in the body that harbor some resistant cells, whcih will then go walk up the exponential growth curves every aggressive tumor always does.
- hughlomas 13y agoI do not intend this as a contradiction but merely a tangential tidbit: Devil facial tumor disease [0] is an example of an actual, transmissible cancer in mammals, showing that it is at least possible. [0] http://en.wikipedia.org/wiki/Devil_facial_tumour_disease http://en.wikipedia.org/wiki/Devil_facial_tumour_disease
- dekhn 13y agoOr oncogene transfection, which likely occurs in nature, not just the lab.
- adventured 13y agoWe also know that cancer can be spread / caused by virus, from one person to another (eg HPV, and there are probably others waiting to be discovered). And we know that you can intentionally force the formation of tumors / cancer through introduction. We do this in mice as a regular course of study now. I suspect that over the coming decades, we're going to find cancer is a far more communicable disease than previously thought.
- Dylan16807 13y ago> spread / caused by That seems like a giant conflation to me.
- karmajunkie 13y agoHPV is also an oncovirus, responsible for cervical cancer and very likely many oral, throat, and esophageal cancers. And there's a vaccine for it. [Edit: should be noted however that the vaccine is for the virus, not from the cancer that can arise from its infection.]
- adventured 13y agoAlmost every thing we do is passed on to and alters the next generation we give birth to, even if only in a very subtle way. My question would be, why wouldn't cancer continue to evolve with our immune systems? We're not abolishing the process that leads to cancer, or making cancer impossible. This therapy kills it after it comes into existence. What would prevent a modified immune system from being passed on, and what would prevent an evolution on the kind of cancer that said immune system is susceptible to? That is, why wouldn't the next generation of cancer become that much more challenging to fight, requiring constantly evolving the therapy? Not asking to be pro or con, but genuinely curious about this.
- jamesbritt 13y agoPerhaps because most people reproduce before their body evolves a superior cancer?
- codeflo 13y ago> What would prevent a modified immune system from being passed on The fact that modifying your immune system doesn't automatically modify the part of your DNA that encodes how to create an immune system. Children don't inherit your experiences, they just inherit your DNA. (For the same reason, cutting your leg off doesn't cause your offspring to have a missing leg.)
- philwelch 13y agoHow exactly is cancer adaptive anyway? Think about how natural selection works: genes that are better at surviving and propagating themselves survive and propagate themselves. Bacteria evolve because they're an independent genome that infests other organisms but cancer is just a failure mode of biology.