I don't have Showtime, so probably will not see this show. But I can tell you this: My sister had a brush with breast cancer in 2001. She had the lumpectomy, and daily radiation with another re-excision following that.
While she was going for radiation therapy, she became friends with two more women who were also patients, but in much more advanced stages of the disease. They, too, were undergoing radiation, and one of them was also receiving chemotherapy. I found out that they were receiving palliative treatment--designed to keep them as comfortable as possible for as long as possible.
These two women, though, presented a face of humor to the world at large, no matter what their private struggles were. One of them eschewed the wigs designed to conceal hair loss, and instead wore the most outrageous costuming wigs she could find: One was a long Lady Godiva style wig, in fluorescent green. The other woman wore a turban and, shortly after the attacks of 9/11. a tee shirt that said, "I'm not a terrorist! I'm doing chemo!"
Even though their disease ultimately proved fatal, they showed tremendous courage, good cheer, and yes, humor in dealing with it. Grace under pressure. I don't know if either of them were women of faith, any faith, but I would strongly suspect it. Only faith could lead to that kind of acceptance.
And yes, humor in such dire circumstances told my sister that they were not dying, they were living until they drew their last breath.
Thankfully, some nine years later, my sister is still alive and well.