Well, based on naturalistic evidence such as infant cancer, I suppose one could conclude that there is a horribly inept or insane designer (or designers), but I personally see no reason to believe that.
One could conclude that the infant was exposed to cancer causing chemicals or radiation or disease but conclusions are not the same as proof and so the infant cancer thing is pretty much a nonstarter for evidence of anything.
Other than perhaps that the young can get cancer too.