David, I have always heard it pronounced, as you pronounce it,
"Kah-nee-sus". I would suppose that folks from the Buffalo area would
be more inclined to say it with the "yus" sound, simply because they're
more familiar with that name. I would also have to assume, that there
is a likelihood of a "Cansius" presence in areas other than Buffalo, but
I'll bet you mostly heard it from Buffalo people.
OR...they probably the same people who say
"NUK-U-LAR!! Go figure!!
Carole