Most cells stay in the same place, die when told to and don't make more copies. Necessarily some of your cells don't obey one or more of these rules (you wouldn't last long if your blood cells weren't endlessly copied for example or if they stayed in one place). But if all three rules get broken you've got cancer.

The cancer I had when I was young, Hodgkin Lymphoma, is one extra rule broken because the lymphatic cells already don't stay in one place and makes extra copies of themselves - which is why it relatively often occurs in young people. One copying error and the "Die when told to" feature breaks in the new copies and now you've got cancer.

Sorry but this is just false. Everyone has "cancer" all the time because these "mistakes" happen all the time. The reason why someone gets the medical condition, "cancer", is because for some reason, the immune system stops cleaning up these rouge cells. That could be a huge infection or injury, general decay of your body, etc, causing a cancer clump to form. Once cancer reaches a certain size, it will develop mechanism, like acidity, that will inhibit immune response regardless of whether the immune system would now classify the cancer as a threat. In any event, cancer is a very complicated condition, with many different causes. It's unlikely there will be a one-size-fits-all solution.

Well the position being discussed, different from the current consensus, is that what sets apart the "cancer" condition from routine mutated cell line is metabolism, not immunity to the immune (!) system.

In that spirit, subsequent mutations that confer resistance can be seen as a consequence of this abnormally high metabolism rate that overwhelm the system and also cause increasing mutation rates.

In conclusion, while cancer may indeed become a complicated condition to treat, the root cause thus defined is rather simple. Whether this paradigm is valid and useful is an open question, but the article being discussed sure seems to point that way.

This is true for most stationary cancers before they turn malignant.

Immune cells are already resistant to each other, and especially to stress. Additionally, they have pieces of genetic code that are manipulated during their life and potential to become self-reactive with no activation. If they lose anergy and apoptosis, it can be enough, and there are many paths to activate them into mitosis.

Immune cells can become a cancer just by their number and statistics of error. Just big leukemia is but a symptom but has potential for first stage cancer.

"If I remember their argument correctly, cells that "only" reproduce anarchically present little danger (benign tumor) if they don't also do so at an abnormally fast rate / metabolism."

Forgive this (very tortured) analogy, but I think there is a lesson here for would-be extropians who think society will simply tolerate a few vampires here and there.

Specifically: they'd better be living lives of quiet, impoverished contemplation ...