It was the day they planned to run the Race for Life – and it was also the day Caroline Williamson and her two children were given devastating news.

Doctors could do nothing more to save the life of her husband Rob who had a brain tumour.

Despite the heartbreak, they went ahead and ran the 2014 race – and now they are planning to join this year's event in memory of Mr Williamson, who died a month later.

Mrs Williamson, 39, and her children Lucy, 11, and Ed, nine, (pictured) from Marham, near King's Lynn, have also been chosen to sound the starting horn at the Houghton Hall event on Tuesday, July 21.

Mrs Williamson, who will be wearing a pink whoopee cushion outfit as she knows it will make her children smile, said: 'The kids miss daddy massively. They get something out of doing Race for Life because they know they are doing something positive and love seeing the fundraising totals go up.

'You hope it will help other people, that's why you do it; you do it in his name but you want to stop other people going through all the awful things Rob went through. If I could do that I'd dress up in a whoopee cushion every day.'

Mr Williamson, an engine mechanic at RAF Marham, was diagnosed with bowel cancer in 2007 but defeated the disease.

Six years later cancer returned and a brain tumour was diagnosed.

He finished his treatment but then started to feel ill again - and in July 2014 a second brain tumour was found.

After the family took part in last year's event, they took their photographs to show Mr Williamson in hospital.

Mrs Williamson, who works from home as an administrator, added: 'When we showed the photos, Rob knew we had done it all for him, it was all for Rob.

'Within the month he had passed away. He went quicker than expected but he was a fighter. Rob never gave in until the end.'

Cancer Research UK's Race for Life, in partnership with Tesco, is an inspiring women-only series of 5k, 10k and Pretty Muddy events which raises millions of pounds every year to help fund vital research. Boys under the age of 12 can also take part.

Danielle Glavin, Cancer Research UK spokesman for Norfolk, said: 'Every hour, around three people are diagnosed with cancer in the East. That's why we need women of all ages, shapes and sizes to pull on their leggings, lace up their trainers and join Caroline, Lucy and Ed to help conquer cancer.'

• To enter Race for Life visit www.raceforlife.org or call 0300 123 0770.

• Caroline's just giving page - www.justgiving.com/carolinewilliamson

Have you an extra-special reason to take part in this year's Race for Life? Email david.bale2@archant.co.uk