FalloutJack said:
I have a fairly-important question about cancer, and I think this thread begs its asking if it hasn't been asked already:
Cancer is essentially a case of a group of cells who alter their structure and their function to essentially grow in a prolific manner that works against the body which it has been born into. Has anyone ever found out what exactly cancer is actively creating? All these tumors and tendrils grow and regenerate like hell, resist multiple means of destruction, and sometimes resurge in again later in life after a period of dormancy. It's some very adaptive shit, if as Dr. Malcolm says "Life will find a way", what's this particular living cell achieving? It's not like viruses or bacteria, it's not parasitic or symbiotic, and it does not pass along to anyone EXCEPT in whatever gene activates a cancer cell in the first place. So, where does it come from and where is it going?
There is no plan, but there is a reason that tumors grow in certain ways, and it's not purely random. Each living cell, tumor or otherwise, needs a steady supply of nutrients, oxygen, and a means to get rid of metabolic waste. In practice, this means access to the blood supply. What most tumors end up doing is following basic cellular programming to a destructive degree. Most cells in our bodies are programmed to react in certain ways to their chemical and physical environment. It severely limits what they do, and sort of connects them to the larger network of other cells and the body at large.
Cancer cells have gone haywire, specifically in their reproductive aspects (there is more to it, but this is the essential point) and are reproducing without a homeostatic relationship to surrounding tissues. They are in essence, in it for themselves, and no longer part of a cooperating organism. The body generally makes some attempt to kill it, strangling small blood vessels and sending immune cells to attack the cancer. The cancer responds (not intelligently) by trying to get more blood, more food, and it does this by growing and reproducing. A tumor is just a big, messy mass of tissue that was all trying to get food and oxygen.
As the tumor grows though, since there is no plan and each cell is just trying to stay alive, the tissues they form are weak and unable to sustain themselves. Large tumors become necrotic (they die) because they're just masses of tiny blood vessels, and not made to spread oxygen and food throughout the bulk of the tissue. Cancers in the bone lead to porous, deformed bone because the cancer isn't trying to be a dense bone, or packed along the existing extracellular matrix, it's just growing outwards looking for food.
In essence, cancer is the birth of a rogue cell line in your own body, and it takes you over, killing you in the process. It out-competes your original cells for food and space, and since you need that to live, you die. In the process it replaces parts of you that are critical to your survival, like your lungs, or brain, or bones, or the elements of your blood. It's the body gone haywire, resorting to a kind of "original" biological plan, that's all.