A .45 slug with velocity 1200 fps from the side, impacting just above the ear, will have doctors scrambling with a whole different point of view than a .22 from the front, through the earlobe.
So each tissue type has a fairly discrete set of receptors, and it's own natural growth patterns, and there are a lot of chemo agents with widely varying transport and absorption characteristics, and modes of action once assimilatied. . . . and produce and release somewhat varying mediators that produce cancers elsewhere in somewhat varying ways. . . .
But it is my point that chemo drugs generally attempt to kill cells with some hoped-for predilection for the rapidly-dividing cells. . . . . and are dosed to come close to lethality for the whole tissue. . . . and just smacks to me like the old "magic bullet" strategy all the same. . . .