Runner to complete World Marathon Majors for cancer prevention research
The race will mark the halfway point in Val Aguilar’s effort to complete the original World Marathon Majors – a challenge in memory of her best friend who lost her life to brain cancer at just 18 years old.
The TCS London Marathon marks the third of Val’s six races, placing her midway through the series which also includes Tokyo, Boston, Berlin, Chicago, and New York.

In London, Val will be running for World Cancer Research Fund – a charity that examines how diet, nutrition, weight and physical activity affect risk of developing and surviving cancer
Val met Mary Katherine in the first year of high school where they formed a friendship that would last a lifetime.
“With her, everything felt like an adventure. Even the simplest or the silliest of things felt like the coolest thing to be doing,” Val shared.
Just four years later, in March 2009, Mary Katherine was diagnosed with an aggressive brain tumour. Despite doctors’ best efforts to save her life, she survived just 14 months after her diagnosis.
“Having such a special meaning behind my miles after losing a best friend to cancer makes each run a little bit easier, and each race experience a little bit sweeter,” Val explained.
Through years of training, international travel and physical challenges, Val is fundraising to support organisations committed to understanding, preventing, and treating cancer.

“When I’m racing, I think about who Mary Katherine would be now almost half our lives later. It makes me feel close to someone who I can no longer grow closer to,” she shared.
Val’s London Marathon bid for World Cancer Research Fund highlights the importance of evidence-based prevention strategies and global collaboration to reduce cancer risk.

World Cancer Research Fund’s UK Director, Steve Greenberg, commented:
“We are incredibly grateful to Val for her determination and dedication to supporting cancer research. Her efforts not only raise vital funds but also inspire others to take action in the fight against cancer. By completing the world’s most iconic marathons, Val has transformed her grief into action, proving that one person’s determination can help drive change.
Val hopes her story will encourage others to fundraise for cancer research, live healthier lives, and spark vital conversations about the importance of prevention.
You can show Val your support by donating or sharing her story below: