Lucy Davis, the actor best known for playing Dawn Tinsley in The Office, has said she has incurable stage four breast cancer.

The 53-year-old said she was diagnosed a year and a half ago and the disease had metastasised to her bones including her spine, right hip and ribs. She said it was too late for chemotherapy.

Davis wrote on Instagram on Tuesday: “As of now, I’m trying to live out whatever might be left of my life in as fun a way as I possibly can.

“I always like to find the teachable moments in anything negative that happens. And cancer has not disappointed in that regard; there’s a lot I have learned from it, and I’m grateful for that.

“As some of you will know, the pain can really be something else. Standing and walking for too long a time can be hard, and I need to use a wheelchair sometimes (so if you see me toddling around in one, feel free to give me a push!).”

Davis, the daughter of the comedian Jasper Carrott, said one of the most important things that had helped her was humour, asking her friends and family to poke fun at her “as much as possible” and to not treat her like a “sick person”.

“There’s nothing that will make you feel more unwell than being treated as if you’re unwell,” she added.

“I’m not scared of whatever comes next. I’m at peace with it. I’ll see my Gracie [her late dog] sooner than expected, and for me leaving my physical body just means going home. Any and all grieving is for my family; it’s far harder for them than for me.”

Davis rose to fame playing the receptionist Dawn in the original version of The Office, which followed the lives of workers at the Slough paper merchant Wernham Hogg, with the show’s co-creator Ricky Gervais playing the manager David Brent.

She played Hayley Jordan on BBC Radio 4’s The Archers for nearly 10 years and appeared in the 2004 comedy Shaun of the Dead opposite Simon Pegg and in the Netflix series Chilling Adventures of Sabrina.

She said she would continue working for animal rights and would like to keep working as an actor, a job she said was one of the “biggest joys” of her life.

She said: “For those of you on a similar journey to mine, I do wish you well. Cancer asks a lot from us, physically and mentally. And we all get to do it however we choose.”