besides, nobody is asking to cure cancer in all population for all times. but in specific individual. who may or may not reproduce later in life.
EDIT: don't need to downvote me being curios. if i didn't ask, this guys who answered would have less chance to post this usefull stuff . so i'm somewhat beneficial to this.
What he means by "evolution at the cellular level" is that every cell in your body normally performs a delicate dance of differentiation, replication, and death to keep all your organ systems operational--this is why skin and bone heal after injury and your lungs don't outgrow your ribcage. It is somewhat akin to how organisms at the ecosystem level perform a dance of diversification, reproduction, and death in equilibrium with their environs.
Cancer is when certain cells in your body become "greedy" about their own survival without regard to the survival of the organism as a whole, and begin to literally compete with the rest of the cells in your body for resources. Normally there are regulatory switches that tell cells to kill themselves when they become damaged beyond the point of repair, but tumor cells have found a way to bypass these safeguards (either because of chance DNA damage at exactly the right sites, genetic susceptibility to malfunction of the safeguards, viral infection, or some combination of the above). As an example of how tumors compete with your other cells, they usually secrete growth factors to create new blood vessels feeding them at the expense of surrounding tissue.
Pretty sure he didn't imply that cancer drives evolution.
wikipedia on cancer: "A large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body.... Cancer occurs when problems in the genes of a cell prevent these controls from functioning properly. These problems may come from damage to the gene or may be inherited, and can be caused by various sources inside or outside of the cell"
I think he implied that cancer is an inherent flaw in the gene based reproduction used by complicated organisms. That our genes' ability to mutate, which introduces new and evolutionarily selectable attributes during sexual reproduction, can play up because of things like "tobacco use, infection, radiation, lack of physical activity, poor diet and obesity, and environmental pollutants.", and lead to cancer.
I'm not saying it's totally 100% correct, although I suspect it is close, just explaining what I think he meant.
Cancer is a series of mutations that enable a single cell to out compete other cells in the body for resources and reproduce exponentially. The final stage of cancer is generally some cancer cells that learn how to travel though the body and end up in a new location. However, rather than a simple disease it's an evolutionary process than can result in a brand new parasite as long as the cells learn to adapt outside the original host.
http://en.wikipedia.org/wiki/Devil_facial_tumour_disease
Warning, clinking on that link may give you nightmares.
besides, nobody is asking to cure cancer in all population for all times. but in specific individual. who may or may not reproduce later in life.
EDIT: don't need to downvote me being curios. if i didn't ask, this guys who answered would have less chance to post this usefull stuff . so i'm somewhat beneficial to this.