Kieran O’Sullivan, from Cork, was a loving husband, father, and friend. In August 2020, while on the beach with his wife, Margaret, he suddenly became unwell and suffered a seizure. A few days later, he was diagnosed at Cork University Hospital with glioblastoma, an aggressive and fast-growing brain tumour. Despite two surgeries and radiotherapy, Kieran’s condition worsened. He died at home on 11th March 2021, aged 58, just six months after his diagnosis. His son, Darragh, who now lives in London, is fundraising for Brain Tumour Research in his memory.
Here is Kieran’s story, as told by his son, Darragh...
My dad, Kieran, was everything you would want in a father. He was genuine, intelligent, and funny, with a kindness that came so naturally to him. He was selfless to a fault. He was a loyal friend, a loving husband to my mum, Margaret, and an incredible dad to me and my brother, Ronan. We were a very close family, and I was especially close to him – he was my best friend, and he still is my hero.
He started out as an electrician, but through hard work and determination, he educated himself and became a qualified process engineer. That really sums up the kind of person he was: always striving, always learning, and always putting others first. No matter what he achieved, his family was always at the centre of everything, and life in Cork, where we were all born and raised, felt full and normal before his diagnosis.
Everything changed on 29th August 2020, when he was on the beach with my mum and suddenly became unwell.
Dad had a seizure where he couldn’t speak or respond, even though his eyes were open. It was terrifying for her to witness and completely out of the blue.
A few days later, in Cork University Hospital, following an MRI scan, we received the news that he had a brain tumour, and I don’t think anything can truly prepare you for hearing those words. We were stunned, and even now, five years later, it still feels surreal to think back on that moment.
Dad underwent two surgeries, where the surgeons removed as much of the tumour as they could without causing damage to his brain, and afterwards we were told that it was glioblastoma. Hearing that it was aggressive, incurable, and terminal was devastating, especially when we were told he had around two months to live.
He went on to have radiotherapy and for a while it seemed to help as he began to improve and we started to see glimpses of the man we knew so well. Those weeks were incredibly precious to us as a family, because having that extra time with him meant everything, and it’s something I will always be grateful for.
As time went on though, the symptoms returned and gradually worsened, and the months that followed were incredibly difficult in ways that are hard to fully describe.
Watching someone you love go through that is something no family should have to experience.
But in the middle of it all, there was some comfort in knowing that he was at home with us, surrounded by his family in a place that was familiar and full of love.
Dad passed away peacefully at home on 11th March 2021, around six months after his diagnosis. While losing him was devastating, it meant everything to us that he was never alone and that we were able to be there with him until the very end. Because it was during the COVID-19 lockdown, everything around his passing felt even harder. We didn’t have the chance to properly celebrate his life with extended family and friends or give him the send-off he truly deserved.
That is a big part of why I decided to take on running in his memory, as it gives me a way to honour him and celebrate his life in a way that we couldn’t at the time. When I saw that the team at Brain Tumour Research were sponsoring the Robin Hood Half Marathon, I felt compelled to get involved, and I can’t wait to support the team.
When I run, I always feel like Dad is beside me, which makes it feel like I’m spending time with him again, and that’s something I really hold onto.
Raising money for Brain Tumour Research has been an honour and knowing that I’ve helped raise more than three days’ worth of funding towards glioblastoma research so far makes it even more meaningful. In 2023, I ran the London Marathon and raised more than £10,000, so taking on the Robin Hood Half Marathon feels really special as my second big challenge for the charity in Dad’s memory.
I’ve learned more about the work being done at the Brain Tumour Research Centre of Excellence at the University of Nottingham, where scientists are using tools like AI, advanced brain imaging, and genetic research to better understand why these tumours come back and how to stop them.
Brain tumours are still one of the least understood and least funded forms of cancer, and that has to change. We need to face them head-on and invest in the research that will lead to better treatments and, ultimately, a cure. If sharing my dad’s story can help raise awareness or contribute in any way towards that goal, then it’s something I’m incredibly proud to do.
Darragh O’Sullivan
May 2026
One in three people in the UK knows someone affected by a brain tumour. This disease is indiscriminate; it can affect anyone at any age. What’s more, brain tumours continue to kill more children and adults under the age of 40 than any other cancer yet, to date, just 1% of the national spend on cancer research has been allocated to this devastating disease since records began in 2002.
Brain Tumour Research is determined to change this.
If you have been touched by Kieran’s story, you may like to make a donation via www.braintumourresearch.org/donate or leave a gift in your will via www.braintumourresearch.org/legacy
Together we will find a cure.
