I say icky from childhood memories of the front cover. It was a book located in the teenage section of the library, but I could peep in at the cover through a gap in the shelving for some innocuous reference books. The cover had two humans in some sort of laboratory experiment, inside two glass enclosures with some sort of gunge rising up at them.
When I was particularly daring I crept in and read the back cover speil, it mentioned something about a sadist who pitted humans against each other in battles to the death, flamethrowers and mazes were mentioned.
This was back in the 80s and the details above were all that I could remember, anyone else recall it?