Precision medicine is diving into the DNA with a knowledge that everybody's tumor has a unique genetic profile and you want to be able to identify that specific piece of DNA that has become mutated and that is driving cancer growth.

Precision medicine is one way to attack cancer and it's proven to be very effective but, remember that like HIV/AIDS, you're going to need combination therapies.

The four most common cancers that account for about 80 percent of all cancer deaths are lung, breast, colorectal cancer, and prostate cancer.

The key to HIV/AIDS was to say let's give a patient multiple different therapies at the same time and that makes the virus much less likely to mutate.

There are clearly environmental factors that can decrease the incidence and death from cancer. I would still say though that the majority of cancers cannot be prevented at this point, but they can be treated and they can be treated two major ways.

When I think of cancer prevention, I think of cancer vaccines, but I think more broadly of all that we can do to prevent cancer. And part of that is coming up with a vaccine that will work like the vaccines we have for hepatitis B or flu or polio.

Probably all of us have random rogue cancer cells floating around in our bodies but by and large, in the majority of cases, our immune system circulates and acts as a surveillance mechanism and kills off those few tumor cells.