4 ms·

> the majority of the time the immune system is a-ok with what cancer cells are doing Ok, no. The majority of the time the immune system prevents tumor formati

by folli 5y ago

> the majority of the time the immune system is a-ok with what cancer cells are doing Ok, no. The majority of the time the immune system prevents tumor formation. Immune surveillance is not really debated [1]. Animals where the immune system is shut down and immunosuppressed patients have a much higher chance to develop cancer. The paper you cite even underlines the point that immune evasion is a failure and not the rule. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1857231/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1857231/

jacquesm 5y ago
That's the third comment that says the exact same thing. Obviously, we are within the 'war on cancer' talking about the remainder, not the ones that the immune system dealt with successfully.
- inglor_cz 5y ago
  This is a shifting standard, though. Our immune systems are much worse in our 70s than in our 20s, and we suffer from many more cancers in our old age. This correlation probably isn't completely random. I am cautiously optimistic about potential rejuvenation of immune systems in older adults. There already were successful experiments (google TRIIM and TRIIM-X by Dr. Greg Fahy) that restored function of the thymus in older people (people, not mice!). Active thymus likely translates into a better function of T-lymphocytes, vital soldiers in the immune army.
  - jacquesm 5y ago
    Part of that is simply that the cumulative copy errors of cells several generations old incurs a higher chance of cancer as well as the higher chance of those cancers not being detected by the aging immune system. So there is degradation on multiple axis at once (and probably others that I'm not even aware of). > I am cautiously optimistic about potential rejuvenation of immune systems in older adults. That's a worthy goal.
    - inglor_cz 5y ago
      Random errors in DNA are part of the picture, but we have error-correction mechanisms as well. It is possible that those mechanisms go haywire as we age, too. It is interesting that short-lived animals like mice tend to suffer from cancer a lot, while huge, long-lived beasts such as whales and elephants seem to be very resistant to cancer, even though they have a lot of cells that can go wrong. Their anticancer mechanisms are obviously much better than ours. We might yet learn something from them.
      - jacquesm 5y ago
        That might be the other way around though: in order to become a large beast you really need that error correction. Similar with viruses: small viruses are typically RNA because they don't need that error correction as much as their larger counterparts which are typically DNA based giving much better resilience against mutation (and hence a much lower mutation rate).
- folli 5y ago
  Sorry, I was getting riled up about the "majority" part of your statement and trying to find some references with quantitative estimates (which you were also wondering about in your response to a sibling comment). The other comments snuck in meanwhile...
  - jacquesm 5y ago
    Yes, I should have been more careful in wording that, obviously if the early stage stuff gets snuffed out we won't know about it. But the numerical angle is an interesting one and the ratio between the cancers that are caught versus the ones that aren't (and maybe per age cohort) could be quite insightful.

by folli 5y ago

jacquesm 5y ago

That's the third comment that says the exact same thing. Obviously, we are within the 'war on cancer' talking about the remainder, not the ones that the immune system dealt with successfully.

inglor_cz 5y ago
This is a shifting standard, though. Our immune systems are much worse in our 70s than in our 20s, and we suffer from many more cancers in our old age. This correlation probably isn't completely random. I am cautiously optimistic about potential rejuvenation of immune systems in older adults. There already were successful experiments (google TRIIM and TRIIM-X by Dr. Greg Fahy) that restored function of the thymus in older people (people, not mice!). Active thymus likely translates into a better function of T-lymphocytes, vital soldiers in the immune army.
- jacquesm 5y ago
  Part of that is simply that the cumulative copy errors of cells several generations old incurs a higher chance of cancer as well as the higher chance of those cancers not being detected by the aging immune system. So there is degradation on multiple axis at once (and probably others that I'm not even aware of). > I am cautiously optimistic about potential rejuvenation of immune systems in older adults. That's a worthy goal.
  - inglor_cz 5y ago
    Random errors in DNA are part of the picture, but we have error-correction mechanisms as well. It is possible that those mechanisms go haywire as we age, too. It is interesting that short-lived animals like mice tend to suffer from cancer a lot, while huge, long-lived beasts such as whales and elephants seem to be very resistant to cancer, even though they have a lot of cells that can go wrong. Their anticancer mechanisms are obviously much better than ours. We might yet learn something from them.
    - jacquesm 5y ago
      That might be the other way around though: in order to become a large beast you really need that error correction. Similar with viruses: small viruses are typically RNA because they don't need that error correction as much as their larger counterparts which are typically DNA based giving much better resilience against mutation (and hence a much lower mutation rate).
folli 5y ago
Sorry, I was getting riled up about the "majority" part of your statement and trying to find some references with quantitative estimates (which you were also wondering about in your response to a sibling comment). The other comments snuck in meanwhile...
- jacquesm 5y ago
  Yes, I should have been more careful in wording that, obviously if the early stage stuff gets snuffed out we won't know about it. But the numerical angle is an interesting one and the ratio between the cancers that are caught versus the ones that aren't (and maybe per age cohort) could be quite insightful.