Paul McDonnell died at 28 years of age, just weeks before his birthday, from a rare form of cancer.

But his friends and brother have vowed his memory will live on.

With sponsorship of more than £2,000 already in, the five are determined to raise more by cycling 90 miles around Lough Neagh, with proceeds to the NI Cancer Centre, which cared for Paul.

His distraught mother Vivienne told of her heartache after her oldest son was diagnosed at 27.

“It was a huge shock,” said Mrs McDonnell. “You just don’t expect that to happen to your 27-year-old son. You don’t realise what something like cancer is until it hits you.”

Paul, from Randalstown, was diagnosed with the cancer ewing sarcoma in August 2007.

The Queen’s University Belfast Law and Accountancy graduate underwent chemotherapy, followed by an operation to remove the tumour in March 2008.

He then received chemotherapy and radiotherapy for five months after the surgery, before getting the all-clear in October.

“Then Paul started having pains in his chest again and they gradually got worse,” his mother said.

“He had a scan before Christmas in 2008 and he was told the cancer had returned — and that there was nothing they could do.

“He went back to the Cancer Centre in January, where he died four weeks later.”

Paul, a past pupil of St Louis Grammar School in Ballymena, passed away on February 9, 2009.

During treatment, he applied to study medicine, again at QUB.

“He started to feel he should have gone into medicine, specifically cancer research, so he could help people,” Mrs McDonnell said.

She added Paul was very close to her, father Michael and his younger brother Dominic (28), who is taking part in the cycle.

“It was terrible but somehow we helped each other get through it.”

Close friend, engineer Alastair Barr (30), one of the cyclists taking part in Lap The Lough on August 29, said: “Paul appreciated everything they did for him at the Cancer Centre and we are doing this for him,” the engineer said.

For more, log on to www.just giving.com/lapthelough2010.