Hiss of Death, by Rita Mae Brown & Sneaky Pie Brown. Unabridged audio.
This is the 19th novel in the series, and from my records, it is the 16th that I have read.
There is a bit of a formula in these books. When the big social event at the start of the book was a breast cancer fund-raiser, it was no surprise that a character would later in the novel get the disease. What did surprise me was that the cancer patient was series protagonist "Harry" Haristeen. That was a bold move, and I won't give spoilers on that particular plot point.
The cancer plot basically serves as the "A" plot of the novel, as much time and space as it takes up, while investigating the suspicious deaths of hospital workers seems more like the "B" plot. Brown has always inserted political and social commentary into her novels, but in this case, these non-plot moments stood out more than usual.
The mystery plot is handled proficiently, Harry and Deputy Cooper being ably assisted by Harry's pets. Mrs. Murphy, Pewter, and Tucker ably fill their "Greek chorus" role, as always.