An eight-year-old boy who had previously fought off a rare and aggressive form of cancer only to see it return a few months later has passed away, his parents have confirmed. Mark and Becky Bell announced that their son, Luke Bell, succumbed to his neuroblastoma on Christmas Eve and that their world has now "changed forever."

According to the Daily Mail, Luke, of Darlington in County Durham, had been battling the cancer — which afflicts less than 100 children a year in the United Kingdom — for the last two years. Between his initial diagnosis and Christmas 2017, he underwent 11 rounds of chemotherapy, as well as surgery to remove a large tumor wrapped around an adrenal gland and a kidney.

The family even received the excellent news that the eight-year-old was clear of cancer this past January, only to be informed in April that it had returned worse than ever. As Luke's condition got progressively worse, Mark and Becky were given a ray of hope when the boy was accepted into an experimental treatment program at the Pediatric Cancer Center in Barcelona, Spain. 

Because the treatment, which was scheduled to begin this coming January 21, would cost the parents a steep £140,000 (~$170,500), they had made a desperate plea for donations and managed to raise £95,000 ($120,500).

Speaking at the time to the Mail, Mark had tried to keep his expectations in check. "He has been accepted on to the trial, starting on January 21, but he has to be well enough to start it," he had revealed. "In November, his NHS consultant said that his cancer had spread to his skeletal system and that his bone marrow is now made up of 70 percent cancerous neuroblastoma cells. We were told he has only got weeks – or a few months at best – to live."

But just hours after making the plea for the donations, the parents delivered the devastating news that the eight-year-old was no more. "This latest battle has been one too many, and our little superhero is no longer with us," they wrote in a Facebook post. "Luke passed away peacefully, comfortable and in his favorite place surrounded by the people he loved the most. Words can’t describe just how devastated and heartbroken we are, though we can take some consolation from the fact he is now free of pain."

They also thanked all those who had been so supportive of them over the difficult last two years. "As a family, we would like to thank everyone that has been involved with Luke’s journey, whether it’s been donating, fundraising, messages of support or sharing his story," they wrote. " The number of people that have reached out to us over the last 20 months has been a real source of strength and we will always be grateful for that."

Both also insisted his death shouldn't be a "time for sadness" and that their son wouldn't stand for it. "Now is the time for focussing on the positives, the amazing memories and the incredible impact he has had on so many lives," they said.

"At only 8 years old Luke has shown such a huge amount of strength, bravery and courage to fight as long as he did. The world seems a darker place today without his infectious smile."