Inflammaging

Almost every death of a person I know in my age cohort is attributable to cancer.

The following hypothesis has previously made sense: medicine has advanced to such an extent that fewer people are dying of heart attacks, strokes, or sudden trauma; chronic diseases are far more difficult to treat, hence there are more deaths from cancer. However, the aforementioned is only a partial explanation; researchers have discovered that aging immune systems are less able to fight off cancer. [bold added]

(Image from Science Direct)

...studies of individual immune cells in human lung tumors, as well as in old mice, have revealed how chronic, or pathogenic, inflammation in older people—dubbed inflammaging—interferes with the immune system and fuels cancer growth...

Inflammation is the immune system’s reaction to a threat. Immune cells circulate in the body, attacking invaders such as viruses and cancer and calling for backup—more immune cells—when necessary. Working correctly, they can beat back Covid-19 or heal a cut on the finger. But the immune system can also overreact, fueling inflammation that gets in the way of healing or leads to disease. It misfires like this more as people age....

Often the assumption is that older people get sick more easily because their immune systems weaken, says Dr. Thomas Marron, a thoracic medical oncologist who heads the early-phase trials unit at Mount Sinai’s Tisch Cancer Institute. That does happen, he says, but at the same time, “we really are seeing this sort of hyperactivation.”

“The body is just basically like a flower bed primed to grow cancer as you get older,” he says.

As a person ages, the immune system has to work harder to kill infections or mutations, like cancer. But the immune system itself is aging and produces fewer of the type of immune cell that targets and kills cancer cells. At the same time, it makes more of a type of immune cell that responds initially to infections. Known as myeloid cells, with aging they become more inclined to overreact and create inflammaging. These inflammatory cells may provide a “hit” necessary for older cells with mutations to turn cancerous, says [Dr. Miriam] Merad of Mount Sinai.

Combatting defective immunity systems is only of several approaches that are being explored in the race to cure cancer. 54 years after Richard Nixon announced a War on Cancer the path to an eventual victory no longer appears to be impossible.