While Swanton's work is great in revealing how difficult it is to contain a tumor and how evolution allows escape from therapy and in exposing genetic diversity in tumors, the idea that you can "chop at the root of the tree" is (in my opinion) bunkum. First of all, even if you target trunk mutations you can evolve resistance. Second, you can't just keep loading up drugs into patients; they can often barely tolerate one of these therapies (which have off-target effects on normal cells), combination therapies compound the problem.