The genome stability maintenance system consists of many components. The genome can be damaged in various ways. Although ultraviolet and cosmic rays are the first to come to mind, it seems that the main cause of mutations is the activity of the cells themselves. When DNA is replicated, errors occur. Maintaining genome stability is a very active process that consumes a lot of energy. It is beneficial for a tumor cell to disable and break this system in order to develop. She is also fighting the body, and at this moment a real classical Darwinian evolution is taking place. Every life strives to have a lot of it: both a hare and a bacterium. In a multicellular creature, the cells are under the control of the body, it does not allow them to reproduce spontaneously. Therefore, when a cell successfully breaks the control system, this advantage is picked up by selection and leads to the formation of a tumor. The longer the tumor develops, the more changes accumulate. Unicellular organisms are all “cancerous”: they tend to multiply and pass on their genes to the next generations. And a tumor is a rebellion against multicellularity. The human body consists of a huge number of cells. Most of them are updated at an insane rate: the intestine is updated every few days, and red blood cells live for four months. During our lifetime, trillions of cells pass through us, but they are all doomed to die, they will not pass their genetic information on. The exception is gametes, but not all cells in our body can agree with this state of affairs. The tumor tends to throw off the control of a multicellular organism and prefers to act independently. Different tumors behave differently. A lipoma almost never turns into a liposarcoma in humans, but polyps in the stomach are a completely different matter. They quickly degenerate into cancer, so from a certain age it is necessary to undergo a medical examination. If a polyp appears, it is simply removed. In this case, knowledge of the dynamics of the evolution of this type of tumor allowed doctors to develop measures that make it possible to reduce the risk of this type of tumor. And this applies to many types of tumors that can be caught in time at the early stages of evolution. Source: Postnauka