The TV presenter and Childline founder, who revealed in January that the disease had spread, said a scan "will reveal one way or another" if the medication is successful.

Dame Esther, 82, said: "My diagnosis of stage four lung cancer made me realise how very lucky I've been in my life, working with Childline and the Silver Line, and meeting so many fascinating and inspiring people, and especially lucky to have spent 21 years working as producer/presenter of That's Life!

"I'm not good at regrets," she added. "What I treasure most are the fantastic friendships I have made thanks to That's Life! during the last 50 years, the people I met and the team who worked so hard, and laughed so hard, together for so long," she told The Mirror newspaper.

According to Cancer Research UK, stage four is when the cancer has spread from where it started to another body organ and is also called secondary or metastatic cancer.

Ms Rantzen was speaking at an event to mark the 50th anniversary of the launch of That's Life! on Friday.

The show, a weekly mix of investigations, topical issues and entertainment, ran from 1973 to 1994.

It made her a household name and a pioneer for female broadcasters.

Dame Esther, who has three children, set up children's charity Childline in 1986, in addition to her success as a journalist and broadcaster.

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In 2006, the charity - which offers counselling and support for children and young people in the UK up until the age of 19 - became part of the National Society for the Prevention of Cruelty to Children (NSPCC).

In addition, Dame Esther also set up The Silver Line in 2013, a charity which supports elderly people in the UK who are battling loneliness.

Honoured for charity work

She was made a DBE in 2015 for services to children and older people due to her charity work.

In 2021, Dame Esther received the lifetime achievement award at the Women of the Year Awards for her philanthropy.

She was forced to cancel an appearance on The One Show earlier this week because of her illness, the newspaper stated.