Great question. This article might be helpful to you:
From a biological point of view, it is now clear that cancer is an evolutionary disease. Cancer biologists use evolutionary theory because it is useful and accurate, not because they are pushing an “evolutionary agenda.” In cancer, cells evolve a set of new functions. These functions are beneficial to the cancer cell, but ultimately lethal to their host. And cancer must do much more than just grow quickly. It must also…
- ignore signals to die,
- evade immune defenses,
- grow blood vessels to obtain nutrients,
- invade surrounding tissue,
- survive in the bloodstream,
- establish new colonies throughout the body,
- and even resist treatment.
Not every cancer acquires all these functions. Nonetheless, in all cases, more than just rapid growth is required for cancer to develop. Several new functions are required. Ultimately, many cancers will acquire more than ten beneficial (to the cancer cell) mutations that enable these new functions.
“Broken” functions perhaps can make sense of some of the changes, but not all of them. Some of these functions are quite complex. We can, also, quantify the information in bits too.
From the same aritcle:
One incorrect metaphor for cancer (and a misguided way of dismissing evolution) is that cancer is just cells “breaking down” or “gunk in the machine.” Superficially, the “breaking down” metaphor explains some changes in cancer. For example, some cells acquire the ability to divide uncontrollably by truncating, or “breaking,” specific proteins that normally control cell division.
The “breaking down” metaphor, however, is not adequate. When our technology breaks down, it never produces anything resembling cancer. Old cars, laptops, and watches do not grow tumors as they break down. In this way, cancer reminds us that biology is unlike any human design. Cancer is unique to biological systems, and we are afflicted with it because we are intrinsically capable of evolving.