WHEN Sheila Hancock’s grandson Jack started complaining of headaches and feeling sick, doctors told his mother Melanie Thaw not to worry – it was probably just a virus.

But then the four-year-old had a really severe bout of vomiting and Melanie knew it was serious.

“He was not a complaining child, his pain tolerance was obviously very high, but this time it just wouldn't go away and no amount of pain killers would get rid of it,” says Melanie, 46.

“At four years old he couldn't really describe what was happening to him, he just kept saying, ‘Mummy, it really hurts’.”

After he’d suffered through a weekend of pain, Melanie's GP sent Jack to hospital, where a CAT scan showed he had bleeding on the brain. Immediately, he was taken by ambulance to Great Ormond Street hospital.

“The next day he got an MRI scan, which was when they saw the tumour which was quite big for his tiny little head.”

Brain tumours are the biggest cause of death for children and adults under 40 in the UK than any other cancer. But research into brain tumours receives less funding than breast cancer, cervical cancer, prostate cancer and leukaemia.

Jack was fortunate – and after a life-threatening operation and regular scans, he was given the all-clear aged nine. He’s now a healthy 15-year-old, with little more than a scar to show what he went through.

Melanie has broken her silence about her son's ordeal for the first time to support Brain Tumour Research's Centres of Hope fundraising campaign.

The campaign, led by 18 brain tumour charities, hopes to raise £7 million for seven centres of excellence to discover more about brain cancer and how it can be treated.

Jack’s tumour, only slightly smaller than a tennis ball, was a very rare type – papillary glioneuronal tumour – of which only nine other examples have been seen in the world.

For Melanie, the worst moment was sending her son into the operating theatre to have the tumour removed in a six-hour operation in May 1999.

“You can't prepare yourself for that – to send him in was like dropping him into a ravine or something.

“But you haven't really got a choice... the tumour could have killed him at any time, they had no idea how it was going to behave. It could have carried on growing.”

It was a fraught time for the whole family, especially because just days before the operation, Jack's grandmother Sheila Hancock had been rushed into hospital with an appendicitis, leaving her late husband and Melanie's adoptive father John Thaw shuttling between two different hospitals.

“Dad really bore the brunt of it – I know he had a difficult time being the go-between. But he was brilliant and solid and really pragmatic.”

Tragically John would go on to lose his own battle against cancer just two years after Jack had survived his.

After the operation, Jack began to recover immediately but for years afterwards, Melanie would worry any time Jack seemed to be ill.

She and her partner Matthew eventually had another child, Louis, now three, and Jack is now what she describes as a “normal, boisterous teenager”.

There are 120 different types of brain tumours and 16,000 people in the UK each year are diagnosed with one – or 43 people a day.

Melanie adds: “Further research would mean some other child would not go through this.”

For more information on Brain Tumour Research, visit brain tumourresearch.org