An inspirational Colchester mother living with an incurable brain tumour has vowed to cross the finish line of the London Marathon for her son, who has battled a rare form of eye cancer.

East Anglian Daily Times: Gemma Edgar with son Noah after his surgery. Picture: GEMMA EDGARGemma Edgar with son Noah after his surgery. Picture: GEMMA EDGAR (Image: GEMMA EDGAR)

Despite having monthly doses of chemotherapy which leave her feeling sick and exhausted, Gemma Edgar has continued to train three to four times a week in preparation for the race on April 22.

The 32-year-old said completing the marathon was on her bucket list.

Mrs Edgar was diagnosed with a malignant brain tumour in October 2014, just eight weeks after the birth of her second son Noah.

When Noah was 18 months old, he was diagnosed with retinoblastoma, a rare and aggressive form of eye cancer that affects babies and young children.

East Anglian Daily Times: Gemma Edgar training for the London Marathon. Picture: LW PHOTOGRAPHYGemma Edgar training for the London Marathon. Picture: LW PHOTOGRAPHY (Image: Archant)

After undergoing various treatments and surgery to remove his right eye, Noah is on the road to recovery and is now a happy three-year-old.

Mrs Edgar will run the London Marathon for Childhood Eye Cancer Trust (CHECT), which provided her family with support throughout her son’s cancer journey.

A week after securing her ballot place, Mrs Edgar found out her tumour had regrown.

The determined mother underwent a craniotomy in November and is currently on a six-month course of oral chemotherapy.

East Anglian Daily Times: Gemma and Noah Edgar, from Colchester. Picture: GEMMA EDGARGemma and Noah Edgar, from Colchester. Picture: GEMMA EDGAR (Image: Archant)

She said: “The week after I take the chemo pills is the worst, my whole body feels shattered and all my muscles ache. It takes sheer determination to get out there for a run and I do have to force myself but I always have so much more energy afterwards.

“I did wonder if I should give my place to someone else but I thought, ‘no, I’ve got this on my bucket list’. Cancer has already changed so much in my life. It has stopped me driving, stopped me working, I don’t want it to stop me doing this as well.”

Mrs Edgar added: “I’m just going to go for it. Even if I have to walk half of it I will still raise that money and cross that finish line.”

Noah’s bravery has provided inspiration for Mrs Edgar.

She said: “Noah doesn’t let the fact that he only has one eye stop him at all. Whenever I’m feeling grotty or sorry for myself I think of Noah and the fact that he was only a baby when he went through cancer treatment and he never complained, so I’ve got nothing to complain about.”

Mrs Edgar’s husband Rob and her family will be cheering her on from the marathon sidelines, while Noah and his big brother Dylan will be looking out for her on television.

Around one child a week in the UK is diagnosed with retinoblastoma, and while 98% will survive, more than half will lose an eye in order to stop the cancer spreading.

The most common symptoms are a squint and a white glow in a child’s eye, seen in dim lighting or when a photo is taken using a flash.

Patrick Tonks, chief executive of CHECT, said: “The fact that Gemma is running the London Marathon for us despite everything that she and her family are going through is nothing short of incredible.

“There really are no words to express our awe and gratitude to Gemma and her family for their continued support for CHECT.”

The money raised by Mrs Edgar will go towards supporting other families affected by retinoblastoma and increasing awareness of the little known condition.

Donations can be made on Just Giving.