Moffitt Cancer Center and the global research community have lost a great leader, scientist and collaborator. Dr. Robert J. Gillies died Tuesday morning after an extended illness. His recruitment in 2008 elevated Moffitt’s scientific stature, and his vision and work over the past 14 years made an indelible mark on the cancer center’s success and helped pave the way for our future.

“It is indeed rare for a single investigator to have major impacts on such a broad swath of disciplines. Bob did just that, where he was the Father of Radiomics, a leader in cancer metabolism and evolution, and an innovator in drug development and radiopharmaceuticals. He was indeed a jack-of-all-cancer-trades, and we are unlikely to find his like again. We were blessed by his presence and are inspired by his legacy,” said Moffitt Center Director Dr. John Cleveland.

Gillies was an exceptional and fearless investigator whose pioneering work spanned molecular, cellular and animal studies, clinical trials and image analytics. One key area was his work establishing that the pathophysiological microenvironment of early cancers is extremely hostile, where it exerts powerful evolutionary selection for the outgrowth of malignant clones and contributes to genomic plasticity and the heterogeneity of solid tumors. Given these findings and many others from his group, Gillies and his Moffitt colleague Dr. Bob Gatenby believed cancers could really only be understood through the lens of Darwinian evolution, and together with Dr. Sandy Anderson, they have led the field of cancer evolution to the prominence that it holds today.

“Bob was a brilliant and innovative scientist who generously shared his talent and creativity with everyone who had the pleasure of working with him. He was a wonderful friend and colleague who will be deeply missed,” said Gatenby.

Notably, these studies also led Gillies to launch truly transformative studies that focused on functional and molecular imaging of cancer, specifically with an emphasis on the use of imaging to inform evolutionary models of carcinogenesis and the response to therapy. His work developed the field of radiomics, where one can extract minable data from quantitative features of medical images. His radiomics research, specifically in lung cancer, has helped vastly improve screening and diagnosis, as well as guide clinical decision-making and outcomes monitoring. Often referred to as the “Father of Radiomics,” his vision was for radiomics to be part of the standard clinical workflow in oncology.

Gillies’ work has and will continue to have a lasting impact on cancer research and clinical practice. During his nearly 50-year career, he published more than 400 peer-reviewed articles, many of which were firsts in his field.

• First to grow and maintain cancer cells at high density in a nuclear magnetic resonance-compatible bioreactor
• First to show that the extracellular, and not the intracellular, pH of solid tumors was acidic in vivo
• First pH image of a tumor
• First to show that neutralizing pH could reduce metastases and improve immune therapy
• First to propose a physiologically relevant evolutionary model of carcinogenesis
• First to define radiomics as a discipline
• First to define intratumoral habitats as drivers of cancer evolution. 

Gillies served in many leadership roles, including program leader and center of excellence director. His most recent leadership roles were the Martin Silbiger Chair of the Department of Cancer Physiology and vice chair for Research in the Department of Diagnostic Imaging and Interventional Radiology. He has been an incredible mentor throughout his career, mentoring nearly 80 students, postdoctoral fellows and faculty at Moffitt alone.

“Bob was a remarkable mentor and a hero to countless early-stage investigators throughout our institution and across the world. With Bob, everyone has an equal voice regardless of their title or experience.  Among his numerous abilities, Bob had a truly unique gift of identifying raw talent and then providing them wisdom and guidance for success.  As a close colleague of ours wrote about Bob, ‘He understood where he ended, and you began. That is the quintessential definition of gifted mentorship.’ And indeed, I owe so much of my success and accomplishments directly to Bob’s mentorship. I will forever miss my mentor, my colleague, my hero and my friend,” said Dr. Matthew Schabath.

Gillies’ commitment to cancer research and his colleagues did not go unnoticed. He received numerous awards over the years, including Moffitt’s Research Mentor of the Year in 2016, Moffitt’s Researcher of the Year in 2012, the Academy of Molecular Imaging’s Distinguished Basic Scientist Award in 2019 and a Gold Medal from the World Molecular Imaging Society in 2018. Additionally, he served as a steering committee member of the American Association for Cancer Research’s Cancer Evolution Working Group, which aims to elevate and educate the broader cancer research community about how evolutionary principles can advance cancer diagnostics, therapeutics and prevention strategies.

In addition to his scientific and leadership accolades, Gillies was a loving husband, wonderful father and doting grandfather. He is survived by his sister Beth Bream, his wife of almost 45 years, Christine Gillies, daughter Julia Ford, son-in-law Bryce Ford and grandchildren Kennedy Ford, 9, and Jackson Ford, 7; daughter Jessica Mueller, son-in-law Nick Mueller and grandsons Beckett Mueller, 7, and Nolan Mueller, 3.