Why the war on cancer hasn't been won

He says it has become clear that cancer isn’t a single disease or even a hundred different diseases. “Between everybody that has cancer today, to everybody that’s probably ever had cancer since the beginning of humankind, [each person] has had different molecular alterations in this disease,” he says.

So you could say each case of cancer is a unique disease.

“The other complicating thing is that cancers aren’t static, they actually change over time,” he adds, morphing within each patient. That’s why a treatment that works for a while often loses its punch, and why doctors have to search for some other treatment.