Emma Hannigan was 32 years old when she discovered she carried a potentially lethal gene called BRCA1, a gene which puts one in deadly danger of developing cancer. Happily married to Cian and living in Co Wicklow with their two young children, Sacha and Kim, she'd no intention of enduring a waiting game to see if she'd develop breast or ovarian cancer.
So she struck pre-emptively and had her breasts, then her ovaries, removed, which should have reduced her risk by some 80pc.
But the cancer came anyway and then kept chasing her, beginning soon after her first hospital stay. Seven bouts of cancer on (in less than five years), she's written about the first six battles in Talk to the Head Scarf, an unusual and powerfully upbeat memoir. The seventh is under way.
The decision to have preventative surgery was tough enough but Hannigan's repeated bouts challenged her beyond words, until she began writing. She tells of a defining moment when she decided to take control of her illness. She had discovered a message from a child who'd died of cancer written on a drawing by the child which was pasted onto the wall of a hospital waiting room.
The message said: "Help me to die, I am suffering." (Katie, 7).
"I've never been good as a sitting duck," she says. That grit sustains her, as anyone who saw her recent Late Late Show appearance will have recognised.
The gene Hannigan inherited, on her mother's side, is the more dangerous of two identified with breast and ovarian cancer.
Known as the Ashkenazi Jewish gene, it meant her odds of developing cancer were some 10 times higher than usual. It works like random roulette, as a gun to the head that didn't explode in her mother's case yet did hurt some of her aunts.
Her story is quite extraordinary, even though she downplays it with a lightly unsentimental style that reads like conversation.
While she was undergoing treatment, Hannigan began writing and published her first fiction, Designer Genes, followed by Miss Conceived. Meanwhile, she was also raising her children and trying to help them live their childhoods without a pall hanging over their days.
Funny incidents light up serious moments, such as when Hannigan goes with her mother to buy a wig.
Other moments are harrowing commentaries on the Irish health service. Even her grit is threatened when she and her husband spend hours in an unidentified regional hospital after she falls ill on a rare night away.
Another low point sees her being discharged from a day ward after surgery because, well, that's how the bureaucracy works. Rather than have her spend the night on a trolley, her husband takes her home. Otherwise, Irish cancer services serve her well and she's eager to share her expert savvy about the system.
Talk to The Head Scarf is a meditation about life, not death. Hannigan's charm is that she will not let fear overcome her and won't treat herself as a tragic heroine, even though she's knocked back so many times the reader almost loses count.
"No digging your own grave," she writes. "No giving in or giving up is allowed. There is always hope."