Professor Tracey O’Brien AM is the Chief Cancer Officer and Chief Executive Officer of the Cancer Institute NSW, the state government agency leading cancer control efforts across New South Wales, Australia. She was appointed to the role in July 2022 and is a highly respected paediatric and adolescent haematologist and oncologist with more than 25 years of experience in clinical care, research, and health system leadership.
Prior to her current role, she served as Director of the Kids Cancer Centre at Sydney Children’s Hospital and Director of the Transplant and Cellular Therapy Program, and she has held numerous national and international advisory positions, including Chair of the Cancer Australia Advisory Board and Vice-Chair of the Advisory Board for the International Centre for Bone Marrow Transplant Research. In 2024, she was appointed a Member of the Order of Australia for significant service to cancer medicine, medical research and education.
Under her leadership, the Cancer Institute NSW has strengthened statewide cancer control strategies focused on reducing inequities, expanding early detection and prevention, and improving patient experience through data‑driven, multidisciplinary approaches. During her tenure, the Institute has delivered expanded screening services, including increases in BreastScreen participation, enhanced patient‑reported measures to inform care, and growth in clinical trial enrolments, advancing collaboration between government, clinicians, researchers and community stakeholders. In 2025, she hosted the inaugural NSW Cancer Summit, bringing together experts to shape the future of cancer prevention, treatment and care, reflecting the Institute’s role in driving innovation and equity across the cancer care continuum.
The 100 CEOs featured here reflect the diversity and complexity of modern oncology leadership. In 2025, some lead the world’s largest cancer institutions; others guide specialized societies or emerging innovators. What unites them is responsibility: for millions of patients, for the integrity of science, and for the future direction of cancer care globally.
This list is not a celebration of power, but a recognition of stewardship, accountability, and impact – and of the leaders whose choices continue to shape the fight against cancer. For the many deserving individuals not mentioned in this list, we will continue to acknowledge, honor and elevate your voices in our daily publications from across the world.
See the full list of The 100 Most Influential CEOs in Oncology in 2025, and stay tuned for other special category nominations.
