Hell below has been one-upped. It had a cast of a mere 1,000, but The Big House (1930) claims 3,000!! Just love the 1930s publicity departments.
When the picture was filmed, they had Bob's character married to Leila Hyams who is romanced by escapee and Bob's roomie, Chester Morris. Thankfully, it was decided to change Leila's role to being his sister. After all, Chester was portraying a good guy, not a creep wooing the wife of poor Bob back in The Big House. Good move.
TCM is streaming The Big House until April 27th and The Secret Land (1948) until April 20th.