In both cases, people are being denied their freedom and taken away from their families, for engaging in activities that hurt no one, not even themselves.
It's certainly true that American prisons are better. But given the OP's definition: "enduring starvation, torture, and rape while performing hard labor", we do hit a couple of checkboxes. My understanding is that prison rape, with guards just looking the other way, is still a real problem in America. And take a look down at Guantanamo for (an admittedly small number of) people who are imprisoned and tortured "without legal recourse", as the OP says.
So it's just a matter of degree. There's certainly a good deal of ground for comparison.