Story
This summer, Claire and Sian are taking on a challenge: swimming 3k across the Arctic Circle. They’re doing it not just for the adventure, but with a powerful purpose in mind - to support Sienna, the 7-year-old daughter of our friend and colleague Martin Vallance and to raise money for Great Ormond Street Hospital (GOSH), where Sienna is receiving world-class treatment for a rare brain tumour.
Martin has generously given us permission to share Sienna’s story, in the hope that it will inspire others to support the hospital that has done so much for his daughter and their whole family.
Great Ormond Street is amazing. From the moment we arrived, we were supported by an entire team who do everything they can to make the experience manageable, not just for Sienna, but for us as a family. Every single person we’ve met has been kind, thoughtful and completely focused on helping children feel safe and understood. The doctors, nurses, play specialists, teachers, physios, nutritionists, everyone has played a role in getting us through this. What’s incredible is that almost everything outside of the core medical treatment is funded by charity or provided by volunteers, the play specialists, the bedside teaching, the musicians, even the therapy dogs. The new cancer centre they’re hoping to build will also rely on charitable support. And it’s these things - the extras that aren’t really ‘extra’ at all - that make a real difference to the day-to-day, for children and parents going through the worst times imaginable. We’ll never be able to thank them enough. That’s why I’m proud to share our story, because supporting GOSH means helping more families like ours.” – Martin
In October last year, Sienna was referred to GOSH with severe symptoms of thirst and frequent urination. She was initially diagnosed with diabetes insipidus, which was successfully managed. But during a routine check-up in February, blood tests revealed abnormal tumour markers. An MRI scan confirmed a 6mm germinoma tumour on her pituitary gland - a rare form of childhood cancer, with fewer than 15 cases reported in the UK last year.
Sienna’s treatment began immediately. She is now undergoing chemotherapy and proton beam radiotherapy, an advanced treatment only available at two centres in the UK.
But the treatment is only part of the story. What truly sets GOSH apart is its entirely child-centred approach. Alongside expert medical care, families have access to play therapists, in-house teachers, psychologists, volunteers and a wide range of emotional and practical support, all provided in a warm, welcoming space that feels more like home than hospital.
And now, GOSH is building something truly transformational: a brand-new Children’s Cancer Centre. This state-of-the-art facility will include:
Accommodation so families can stay close to their children
- Healing gardens and play spaces
- Study and work areas for parents
- The most modern, child-focused treatment environment possible
- But this vision requires hundreds of millions of pounds and that’s where your support matters.
Sian and Claire are swimming for Sienna and for every child like her who deserves the very best care in the worst of times. Your donation will help fund the new cancer centre and the vital services that aren’t covered by the NHS.
Every donation, big or small, will help build a brighter, kinder future for children with cancer and support the incredible work being done at Great Ormond Street Hospital every day.
Thank you!