The Radio 5 Live presenter bravely told listeners how she had undergone treatment for cystic peritoneal mesothelioma, which affects the abdominal cavity.
Doctors believe there have been just 153 cases of the disease documented worldwide.
Kate told how underwent “the mother of all surgeries” as well as chemotherapy after the devastating diagnosis was delivered last summer.
Opening up on the station’s You, Me and The Big C podcast, the married mum-of-two said: “If you look at the medical literature, they often quote 153 cases in the world.
““It’s very aggressive, malignant, quite often caused by asbestos.”
BBC Radio 5 Live presenter Kate Williams
“And in the UK I know of three other people, mainly through a Facebook group that I joined.
“If you look at mesothelioma it’s not a nice one to look at.
“It’s very aggressive, malignant, quite often caused by asbestos.”
Discussing her course of surgery, she said: “It’s called MOAS, mother of all surgeries.
“It’s official name is cytoreductive surgery with HIPEC – which is hyperthermic intraperitoneal chemotherapy.
Kate continued: “So they took out the cervix, uterus, fallopian tubes, ovaries, greater omentum, lesser omentum, pelvic peritoneum, another bit of my peritoneum.
“I was really lucky I didn’t have a stoma. And then they pump you full of heated chemotherapy which has been heated up to 42C, so that circulates around inside you for about an hour.
“I keep saying I’m lucky or it wasn’t too bad, my surgery was only about six hours, which you know, people say, ‘oh six hours’ but some patients who have this it’s 12 to 14 hours.”
The podcast was set up by fellow BBC Radio 5 Live presenter Rachael Bland – who tragically died after a two-year cancer battle aged 40 – together with breast cancer survivor Lauren Mahon and Deborah James, who has fought bowel cancer.
It comes as footballer turned Hollywood hardman Vinnie Jones’ wife Tanya tragically lost her six-year cancer battle aged 53.
Legendary racing pundit John McCririck died earlier this week following a secret lung cancer battle.