The risk of cancer fades past the age of 80

gpi | 154 points

I haven't heard this before - the change isn't that large but but it really does drop after 80

My inclination is that this could still just be a selection effect. For people who are prone to cancer, you are probably dead by 80.

https://www.cancer.gov/about-cancer/causes-prevention/risk/a...

marinmania | 8 hours ago

Survivorship bias? The risk of cancer in the 60s and 70s produces cancer patients, who die. The survivors into the 80s had a low individual risk for whatever individual reasons, and continue to enjoy that lower risk, which reflects in their cohort.

Those who died would still have been at risk into their 80s; many of them didn't make it though.

As a pure thought experiment using made up numbers, let's suppose that people are divided into two equal-sized groups: group A has a 75% chance of developing cancer after age 60, whereas group A has zero risk. We have no idea who is in what group. So it looks like people have a 37% chance of getting cancer after 60. Now suppose many of those who get cancer after 60 due to this risk end up passing away. They are of course from group A, and so more of the group B is represented among the survivors going past 80. Since in the 80+ group, the mix of A:B is no longer 50%, but has fewer A people, the risk of cancer is lower.

kazinator | 2 hours ago

Ageing itself is a anti-cancer strategy...

nikolay | 9 hours ago

This is super interesting. I've been wondering for a while about the role of iron in health, with consideration of things like the influence of the iron scavenger P. gingivalis. I do wonder if iron is the real reason for red meat being associated with worse health outcomes.

hgomersall | 8 hours ago
[deleted]
| 5 hours ago

its a dying host and the xenomorph cant be bothered probably

3000 | 3 hours ago

isn't it just lower MTOR activity = lower risk of cancer?

as we age we eat less, move less which slows down MTOR

qqqult | 8 hours ago

>What emerged was higher levels of a protein called NUPR1 in the older mice. This caused cells to act as if they were deficient in iron, which in turn limited their regeneration rates – putting restrictions on both healthy growth and cancerous tumors. ... "Aging cells lose their capacity for renewal and therefore for the runaway growth that happens in cancer."

Translating that to normalspeak: Lower metabolism leads to lower incidence of cancer.

It sounds like common sense to me; cancers form from damage and mutations to DNA during cell replication (kind of like uncaught bitflips during file copy operations), so the less replication there is (lower metabolism) the lower the risk of cancer and vice versa.

Also for some sort of related anecdata: My mother passed from stomach cancer, she had a lifelong chronic iron deficiency due to underperformant hemoglobins which she compensated for by taking iron supplements. Towards the end she ended up getting some iron infusions because her blood iron levels were so abysmally low.

Dalewyn | 8 hours ago

Misleading title. This is true about 5-10% of the human life. For 90-95% of the human life, the exact opposite is happening.

More honest title : "The risk of Cancer Fades Over 80 Years Old, and We May Know Why."

mlok | 7 hours ago

For everyone in disbelief like I was: “… past the age of 80

mynegation | 8 hours ago

[dead]

kidneystereotyp | 43 minutes ago

This is against any established biological common sense I heard of: telomeres are known to be the mechanics of the DNA.

The enemy of these telomeres is age: damage occurs to them during cell division, hence the part of the DNA which watches after the DNA is no longer to fulfill its duty: and that is an open door to all types of cancer.

In other words, if nothing kills you at old age, cancer will do it.

begueradj | 8 hours ago