How can things like sunburns and smoking still increase risk for cancer decades after their damage has been done to the body?

Question

How can things like sunburns and smoking still increase risk for cancer decades after their damage has been done to the body?

In: Biology

Answer 1

Imagine you’re building a brick wall. At some point you used some faulty bricks, but then you finished up the wall with solid bricks and it’s standing fine, those faulty bricks weren’t a major problem. At some point in the future, some of your good bricks get damaged. Normally it wouldn’t be a big issue, but it happened to be right around where those faulty bricks were and now the structure is too weak in that spot and the wall collapses.

Smoking/UV radiation damages DNA, the building blocks of your cells. In much the same way, that initial damage might not cause cancer, but the damage persists throughout your life and makes any future damage more likely to cause cancer.