"I was really discouraged by my representatives, to be honest, and by some of my writer friends," she said. "They really didn't see it."
But then she had her first child, and her own mortality hit her in the face. Hunt said she would cry over her daughter's crib because she was terrified of dying and leaving her baby behind. Translating those feelings into the relationship between Cathy and her son, Adam, made "The Big C" more appealing to Showtime.
"When I pitched the show initially, Cathy didn't have a son," she said. "I had been writing for the broadcast networks and I felt like that might have been too sad, I was trying to keep it lighter. After reading the draft, Showtime gave me one note: 'Could you give her a kid?' Because they felt that relationship would make the show more complex."
"So I thought, what if she has a kid and looks around and realizes, 'This kid is an a**hole. Is that who she's going to leave to the world?'"
Hunt found support from the show's cast.
"It's not making light of cancer," said Reid Scott, who plays Cathy's boyishly cute, still-learning-the-ropes doctor. "It's making light of the situation of cancer. I think the concept was long overdue. We've seen shows about cancer but they've always been such downers. They try to instill hope. This shows the erraticism that happens with people's emotions."
Cancer survivors agree that "The Big C" brings a welcome dose of levity to a topic often talked about in hushed tones. Jen Singer, who was diagnosed with stage three non-Hodgkin's lymphoma in 2007, fought back by blogging about the absurdities of her treatment (belting out Queen's "Bohemian Rhapsody" during a bone marrow test) and challenging friends and family to send her wacky wigs (a blue Marge Simpson number ranks among the best).
Now in remission and writing a memoir, "If Cancer's a Gift, Where Can I Return It?" Singer, a mother of two, said she "would have loved" to have "The Big C" around during her fight.
"I devoured memoirs on cancer for that reason," Singer said. "The funny ones were the ones that touched me. If I didn't laugh, I would have been crying all the time."
Ultimately, Hunt hopes that "The Big C" resonates with audiences the same way. In her mind, the show could never have been anything but a comedy. She won't shy away from confronting Cathy's death -- her plan is for "The Big C" to run for six TV seasons corresponding to seasons on the calendar. But the aim is to uplift, not to drag down.
"To use comedy to laugh during a dark time is such an amazing thing," she said. "Personally, I wouldn't want to watch a drama about cancer. Especially being a mom, I don't like to get that sad that often."