Paula Radcliffe says London Marathon will be emotional as 18-year-old daughter runs after cancer diagnosis

But most significantly for Radcliffe, her 18-year-old daughter Isla, who was diagnosed with cancer in 2020, will be running her very first marathon.

Britain's most successful female distance runner is speaking by video link from her home in Monaco on a typically busy day. She has just been on a run and is squeezing me in before picking up Isla and her 14-year-old brother Raphael from school. Astonishingly, at the age of 51 and a decade since she retired, Radcliffe is also back running marathons.

Although she’s not running in London this year, Radcliffe has been chronicling the build-up to the event with a podcast series, Paula's Marathon Run Club, offering advice to runners at all levels. The series is, fittingly enough, sponsored by Children with Cancer UK, the charity Isla is raising money and awareness for.

Before she was diagnosed in 2020 with a malignant dermal tumour in her right ovary, Isla used to run competitively. "Now she just runs for herself," Radcliffe says. "She's not trying to set any record, it’s just a part of her proving that she’s healthy enough to finish a marathon."

Isla was also aware of the anniversaries. "She was the one who said it will now be three generations who have run the London race, and 40 years since Grandad did it."

That marathon 40 years ago, when the 11-year-old Radcliffe not only watched her father run it, but also saw Norway's Ingrid Kristiansen break the women's world record, shaped her career. She dreamt of doing the same, first achieving her goal (in a mixed-gender race with pace-makers) in 2003, with a time of two hours, 15 minutes and 25 seconds.

But it's not records she’s thinking of today, she says. It’s something far more important – her daughter’s survival. Isla, who has now been clear of cancer for four years, was previously a fit and healthy girl. She’d won the regional under-13 cross country championships in 2020 and was also an excellent swimmer. Then suddenly, during the lockdown of 2020, she found herself permanently exhausted and was sleeping until noon. Radcliffe assumed she had just become a tricky teenager.

But other symptoms became apparent. Isla had always enjoyed competing with Raphael to see how long they could swim underwater, but now she was losing her breath. She was getting terrible stomach aches because of the growing tumour, and then she started bleeding black blood.

"That’s when we knew something wasn’t right, and we went to the paediatrician," says Radcliffe. "It then moved very quickly. On the Tuesday she visited the doctor, we had a scan on the Wednesday and one week later we were already in the hospital starting the first round of chemo."

Was she always confident Isla would pull through?

"I think you have to be. You have to not think of the alternative." But, she says, watching her daughter go through three courses of chemotherapy was horrific. "It’s the hardest thing a parent can go through. You can support them and be with them the whole way through, but you can’t do that chemo for them. It’s horrible to watch your child suffering through that, but at the same time we believed that if it felt bad, it was killing the cancer." And so it proved. The tumour shrank dramatically, and then Isla's ovary was removed.

After Isla was diagnosed, Radcliffe asked her gynaecologist if she could freeze her own eggs in case Isla was left infertile. "He just looked at me and said, 'Look, she isn’t going to want your 47-year-old eggs!'" She laughs. Radcliffe also made another offer. "When she lost her hair, I said I would cut my hair off and get it made into a wig for her. She flat out refused that." Why? "We’d not told many people at the time, and she didn’t want people asking why I’d done it." However much she and Isla prepared themselves for losing her hair, it still came as a shock when it happened. "There are things you’re not ready for – either going through it or as a parent."

After three months off school, Isla returned on a part-time basis. The cancer has gone, but she still has psychological aspects to contend with. "She doesn’t know how it has affected her chances of becoming a parent," says Radcliffe. "She now has a tendency under stress to get allergic reactions on her skin, and we don’t know whether that’s linked to the treatment."

But Radcliffe knows Isla is one of the lucky ones. She says it’s heartbreaking how many children don’t make it, primarily in low-income countries. "Childhood cancer should be beatable. In the UK, 87 per cent of those diagnosed will make it, but in the less-developed world that figure is below 30 per cent." The disparity is shocking, she says.

Isla’s cancer has changed the family in so many ways. They learnt to embrace support from others in a way they never had before. Radcliffe says she wouldn’t have got by without it, not least because Raphael needed looking after while she concentrated on Isla.

"There was a huge amount of mother’s guilt for the fact that you have to focus more on one child for that period of time." But, actually, she says, it brought the best out in Raphael (who represented the Provence, Alpes and Côte d’Azur region in the under-15 national cross country championships in March).

"He’s extremely empathetic, probably in a way that most 14-year-old boys are not, right now. I hope he doesn’t lose that because it’s really special. He’d even let Isla sit and curl his hair when she had no hair to curl, the only proviso being that he would brush it before he went out anywhere! He spent a lot of time with her and worrying about her, and they have a closer bond because of that."

The same is true of Isla and the children's father, Gary Lough (who coached Radcliffe to the world record in 2003). "It was probably even harder for him than me because only one of us could be in the hospital," Radcliffe reflects.

As for her daughter, she says, Isla was forced to grow up quickly, and gained the kind of perspective that many people struggle to find even in adulthood. "Things that her peers might get really stressed about, she handles, because in her mind it’s not that big a deal." Such as? "Fights among friends. She sees the bigger picture. She tells them to their face they’ve annoyed her and then moves on. She doesn’t worry about little teenage things like what you might wear."

Radcliffe is also convinced that the experience has improved Isla’s brain, because it was forced into overdrive when she was catching up. "She says she has a really strong memory now because she had to work so hard." Isla is hoping to go to Durham University to study law.

Radcliffe was always a positive person, but now is even more so. "You’ve got one life, so make the most of it. It really brings that home – value what you have," she says. When she was feeling low, running helped. "It was my coping mechanism. Just being able to get out and run helped me to have more energy to give to Isla when I was back in the room." She believes that’s an important lesson for parents – to look after yourself in order to be fit to help your sick child.

Radcliffe expects Boston (on 21st April) to be her final marathon, which will mean that she has run in all six majors, the others being London, Berlin, New York, Chicago and Tokyo (which she ran in March in a time of two hours, 57 minutes and 26 seconds). Despite her world records and numerous medals, Radcliffe never stood on the podium at the Olympic Games. "Maybe I just wanted it too much, made it bigger than it should have been and pushed too hard for it. But that’s what’s so great about sport. There’s a lot of chance, a bit of luck and a lot of hard work, and it not working out makes it so much nicer when it does."

For the London Marathon, she’ll be commentating as part of the BBC team. Radcliffe knows she’ll have to focus on the elite pack, but she’ll doubtless be tracking Isla’s progress, and hopes to be there at the finishing line for her.

"It’s an extremely emotional place to be anyway, when you see people turn that corner on the Mall and they realise they’ve done it. But when it’s your little girl doing it, that’s going to be a bit more emotional." And I can already hear it in this proud mother’s voice.

The latest issue of Radio Times is out now – subscribe here.

Check out more of our Sport coverage or visit our TV Guide and Streaming Guide to find out what's on. For more from the biggest stars in TV, listen to The Radio Times Podcast.