Interesting new article on cancer mutations

[curious-mind1]

Sorry if the article was already posted on this forum: forbes.com/sites/robinseato...

Arthur

[pjoshea13]

It's puzzling why some men form such strong opinions that chance is not involved in cancer development. (To misquote Einstein: "God does not play dice with the human body."?)

When I started to look at the inner workings of cells, I was struck by the number of mechanisms that are involved in policing cell division.

Perhaps the first word one learns is apoptosis, which is sometimes called cellular suicide. However, efforts are made to repair DNA before resorting to suicide. Recently, there have been posts on BRCA2 & PARP. Both are involved in DNA repair. If there is a BRCA2 defect, PARP can often keep cells viable, which is why PARP inhibitors can be helpful in people with BRCA mutations who have cancer.

Ultimately, there is the Hayflick limit on cell division, controlled by telomere shortening. This only occurs in long-lived animals & is clearly "designed" to halt cells that are dividing rapidly. The cause of telomere shortening is that cells no longer produce telomerase which is responsible for adding a repeat sequence to the end of the telomere. Telomerase is active in stem cells, which are the only "immortal" cells in the body. Cancer cells must circumvent the Hayflick limit - often by activating telomerase activity. Alas, the Hayflick limit is the reason we must die. Efforts to turn telomerase back on in normal cells will likely increase cancer rates.

Estimates of the involvement of chance on cancer occurrence, as I recall, are that roughly two-thirds are due to chance & the rest are due to environmental factors (which includes diet, lifestyle factors, etc.)

I like the 2:1 ratio, since I don't have to beat myself up over all the things I did wrong. On the other hand, young people might be able to lower their risk by up to a third, so there is an incentive to make lifestyle changes.

-Patrick

[curious-mind1 in reply to pjoshea13]

Great reflection, Patrick. I remember my dad's first oncologist, Dr. Myers, saying that cancer is essentially the body's guarantee that it will die. Our struggle, he said, is to make sure that we push that inevitable point as far down as we meaningfully can. I thought that was a very comforting way to look at things: no need to use words like "we beat cancer", etc. No, we live our lives to the best of our ability, and if we have to face cancer, we do the best to push it down long enough to live a full life before moving out.