When a bruise began to form under 13-month-old Harper's eye, her parents initially waved off the issue - but just weeks later, her eye had begun changing shape.
When the bruise showed no signs of improvement, mum Jenny Huddart, 38, and dad Adam Walker, 36 - both teachers from Greater Manchester, England - took Harper to the GP. The dark tinge had deepend, and the affected eye appeared out of alignment.
The GP asked them to return again in two weeks for a review, but appeared relatively unconcerned. While their tot was her usual smiley self, Huddart and Walker couldn't shake the feeling that something was wrong.
At the next appointment, no further action was taken, so Huddart insisted they needed a referral to an eye specialist. An appointment was scheduled for the end of April - about two months after the bruise had first appeared, Metro reports.
But before they could meet with the specialist, Huddart and Walker - who noticed Harper's eye was continuing to change in size - made the decision to call 111. They were advised to take her to A&E, where they were then referred to an eye hospital.
After undergoing a series of scans and tests, the results were returned: Harper was diagnosed with stage four, high-risk neuroblastoma, an aggressive childhood cancer that develops from immature nerve cells.
Doctors told Huddart and Walker the cancer had originated in the kidney's adrenal gland but had since spread to her limbs, ribs, hips, skull, and bone marrow - and she had a 40 to 50 percent chance of long-term survival.
"Honestly, to begin with, we were just in total shock - it didn't hit us fully at first. Then when it did, it was like the world had stopped," Huddart said, as reported by Metro.
Harper was quickly given a treatment plan and started to undergo induction chemotherapy, which may be followed by surgery to remove the tumour from her kidney. Beyond that, she will undergo high-dose chemotherapy and the harvesting, or removal, of stem cells - which would then be followed by radiotherapy and immunotherapies.
"Once the intensive chemotherapy is complete, Harper will have her stem cells returned to help her start to grow new, healthy blood cells," Huddart explained.
The radiotherapy would target the original site of the cancer in an effort to stop it returning, followed by immunotherapy to destroy cancerous cells.
"Harper has stem cells harvested at the start of August and then, depending on the outcome from the scans, we will find out whether she has an operation to remove the primary tumour or onto high-dose chemotherapy," Huddart explained.
"She has coped well with the treatment overall, but has to have a blood count every three days as her platelets are permanently low, so she has had more transfusions than I care to count.
"Harper hasn't lost her spark," Huddart added. "We are hoping the scans show she is responding well, and the cancer has reduced. I'd love them to say it is no longer there, but I know that is a dream not reality."
The parents are now hoping to crowdfund the money for potentially life-saving treatments in the US that are not available via the NHS, with a fundraiser launched on JustGiving currently sitting at £75,500 (NZ$155,550).
According to the fundraiser, Harper currently has less than a 50 percent chance of surviving five years and approximately a 60 percent chance of relapse.
"Once [treatment] is complete, there remains a risk that the cancer will return. We are raising money for Harper to receive revolutionary treatment which could improve her long-term survival, and for any treatment she may need in the future," the fundraiser states.
Neuroblastoma is a cancer that starts in the very early forms of nerve cells - the term neuro refers to nerves, while blastoma refers to a cancer that starts in immature or developing cells.
This type of cancer, which occurs most often in infants and young children, is commonly found in the adrenal glands (small glands situated on top of the kidneys), but it can develop in the stomach, chest, neck, pelvis and bones. While low-risk and intermediate-risk neuroblastoma have a good chance of being cured, high-risk neuroblastoma may be difficult to treat.
