Published Sunday, 14 October 2012
Wee Oscar takes charge while flying to America for treatment. (© Family photo)
The four-year-old arrived in the US last week in the hope that he could begin six months of immunotherapy.
But tests revealed a condition with Wee Oscar's heart means he is not suitable and the family are due to fly back to Belfast as soon as he is out of intensive care. Doctors believe the pulmonary hypertension could be a side effect of the chemotherapy and stem cell treatment.
His mum Leona has now revealed her son has a collapsed lung and asked people to keep the little boy in their thoughts and prayers.
"Quickly immunotherapy was the last thing on our mind," she wrote on Saturday.
"It was clear Oscar faced a whole new set of challenges and dangers right here and now. He very quickly needed help with his breathing, his lungs were collapsing and his heart was failing."
Oscar suffers from stage four neuroblastoma, an aggressive childhood cancer which causes tumours to develop in the stomach, spine, chest and neck.
The Knox family raised £250,000 towards his medical costs in 102 days, and Oscar has become a Twitter phenomenon, gathering support from local stars including Snow Patrol's Gary Lightbody and Olympic boxer Paddy Barnes.
Speaking to UTV before they left for Philadelphia, the Knox family said they wanted to give Oscar "a chance at life".
"We could sit back here at home and cross our fingers, and hope to never see it again but that's not what we want to do," said his father Stephen.
His Wee Oscar twitter account, which the Knox family updates with information about their son, has more than 19,000 followers, and Leona and Stephen have been detailing their journey on a blog.
"Oscar is tough, he's a fighter, but there is only so much a little body can take," his mum wrote -explaining their "dreams" had now "turned to nightmares".
"Selfishly, we need more time with him, we need him to keep fighting. Love you Oscar, and couldn't be more proud of you and all you have achieved in your little life so far. Keep fighting little man."