Hunt explained that now Cathy's cancer is no longer a secret, she will have different challenges to deal with.
"It's been a fun direction to go in since she was a little bit in denial the first season," she told TV Guide.
"Now it's like, 'What are my options? What do I have to do?' Obviously, Cathy is the same person but she's being faced with things that she never thought she'd be faced with so it's fun to see her grow and change."
However, Hunt promised that Cathy (Laura Linney) will still be a forthright character, saying: "She's not going to let anyone or anything stand in her way. She's going to be a little mouthier and a little more honest with friends than I think she would have been previously."
The Big C star John Benjamin Hickey has previously promised that the new season is "funny", while Linney has said that she enjoys working on the show.
The Big C airs on Mondays at 10.30pm on Showtime.