As the SIOP community gathers for the Annual Business Meeting in Amsterdam, we take this opportunity to express our deepest gratitude to Dr. Guillermo Chantada as he concludes his distinguished term as SIOP President.

Over the past four years, Guillermo has led SIOP through a period of remarkable growth, innovation, and resilience. Under his leadership, the Society has expanded its global impact, strengthened governance, and deepened its engagement with members and partners worldwide.

During his presidency, SIOP:

• Established the PARC Programme, and secured €1 million for advancing paediatric oncology research in LMICs, and launched the Early Career Development Grants to support emerging investigators.

• Introduced new initiatives – including Women Leaders, Survivorship, Epidemiology, and AI & Essential Medicines.

• Championed the Global Mapping Project to create a baseline of the current paediatric oncology resources available in each country.

• Strengthened governance through revised Constitution and Bylaws, new Board onboarding processes, and comprehensive policy frameworks.

• Enhanced communication and community through the creation of SIOP CONNECT, the Weekly Bulletin, and a fast-growing social media presence reaching record engagement levels.

• Advanced education and advocacy with structured learning modules.

• Launched the ARIA tool with St. Jude Global.

• Established powerful joint advocacy campaigns with CCI, WHO, and global partners.

• Increased financial sustainability, establishing a Reserves Fund and diversifying income streams to support SIOP’s expanding global mission.

• Oversaw a doubling of SIOP’s membership and significant growth in volunteer networks, webinars, and collaborative programmes worldwide.

• Published the SIOP Global Standards Framework to Strengthen Paediatric Oncology Units in Low- and Middle-Income Countries.

• Expanded the SIOP Secretariat into a team of five professionals, strengthening operational capacity and day-to-day programme delivery.

• Oversaw highly successful annual SIOP Congresses, achieving record participation, abstract submissions, and global reach.

Guillermo’s vision, warmth, and tireless dedication have left a lasting mark on the Society. His presidency has strengthened SIOP’s foundations and positioned it for an even more impactful future. He supported and encouraged our community to make it bigger, stronger and closer to achieving our mission than ever before.

On behalf of the entire SIOP community – thank you, Guillermo, for your outstanding leadership and service.