For many years, doctors have observed a paradox: while the risk of cancer steadily rises until age 80, after 85 the incidence curve begins to flatten or even decline. A new Stanford University study in mice showed that aging itself may suppress tumor development.
In older animals, tumors formed 2–3 times less often and were significantly smaller. Deep molecular analysis showed that aging tissues change the activity of tumor suppressor genes and weaken key signaling pathways that usually drive malignant cell growth.
The PTEN gene, which in a young body triggers aggressive tumor growth, acts much more weakly in an old one. Even cancer cells themselves in older mice retain signs of aging, which prevents them from launching a full cancer program. And this happened even when traditional protective mechanisms, such as the immune system or cellular aging, were disabled.
Although the experiment was conducted in mice, the findings lay the groundwork for new approaches to cancer prevention and treatment in humans. The study also serves as a reminder that age can be an unexpectedly effective ally.
