Why does age increase your chances of getting cancer?

Answer 1

In the current model of cancer development, namely the initiaion-promotion-progression model, cancer development is presumed to be a very time-consuming process. The process of initiation, which is the process of rendering a single cell susceptible to developing into a malignancy, can take mere milliseconds to seconds, usually with the damage of DNA with chemicals or radiation followed by a round of cell division before the damage can be repaired. The initiated cell then needs to be promoted under the right circumstances. If the circumstances are not available, the initiated cell can lay dormant until it is promoted or until it dies. A promotion event always involves the selective amplification of the initiated cell population. The promoted cell can then divide and proliferate and progression begins. During progression, the body will try to either 'remodel' the promoted cells to try to make them behave normally again or kill them via the immune system. Progression is by far the longest of the phases and can stretch for years to decades. The body will initially gain an upper hand and may succeed in destroying the promoted cells. However, as the body ages, various mechanisms involved in remodeling and killing these cells become less efficient and the promoted cells may proliferate beyond the body's control, gaining mutations and eventually form a tumor. Therefore, in general, age is almost a prerequisite for people without congenital defects to get cancer since the normal process of progression takes decades. The body's defensive machinary becomes less and less efficient at stopping the pre-cancer cells as the body ages.