kentron can be acceptably translated as "center." One of Pianka's students, possibly following his teacher, has coined a greater barbarism, "homocentrism."
As for me, give me that old-time humanism.
You're right...I was using the old-time Intermediate Liddell & Scott Greek-English Lexicon and should have read through to the end of the entry for
kentron.
Still, "anthropocentrism" is a neologism. Usually, whatever it is, the Greeks had a word for it, but I can't think of what word they might have used if they wanted to express this idea.