How do cancers have sophisticated mechanisms for evading immune responses when they don’t have any adaptive pressure? The cancer dies with the victim. It seems like the equivalent of mashing on the keyboard and getting a valid program.
They do have adaptive pressure. 100s of millions of years of single cell evolutionary instincts live within our cells and the desire to survive. Being a multicellular organism is a relatively new learned behavior, and a human cell returning to that old mindset is basically cancer.
The only problem is that these individually minded (cancer) cells have every ability of your healthy cells and have basically stopped caring about the greater whole and care about themselves. Then they evolve at a micro level for their survival to fend off chemo, immune system, radiation etc. All it takes is one adapted/surviving cell to come back strong.
The sophisticated mechanisms for evasion exist because they have all the methods of evading your immune system that healthy multicellular organisms need to function and they multiply and increase their mutation rate to try new methods to survive and thrive.
I view cancer cells as single cells to understand their behavior with the adaptations of all the healthy cells returning to their “baser instincts”.
Source: Caretaker of a cancer patient and former cell bio major
They have immense adaptive pressure at the cellular level. The evolutionary process plays out within each patient. Aberrant cells that don’t have some sort of evasion mechanism will be identified and destroyed by the immune system.
I've heard a hypothesis that cancer behavior is not primarily evolved in the patient, but instead it is an ancient mechanism from the time of transition from single cell to multi cell organism.
A human cell can never survive on its own. But there might have been a time when cells could have benefited from "pulling the escape hatch" and taking their chances instead of continuing cooperation within a damaged early multicellular organism.
I’m just another guy throwing ideas, maybe the cancer should be compared to a virus or bacteria, where their life cycle is much shorter than humans, the objective is maximum growth, then it dies as any other organism