This picture of Dr. Kensler was
taken by John Groopman outside
a Tea House in Qidong, China,
and reflects Tom’s joy during
his many years of aflatoxin
research in Qidong.
It is with great sadness that we share with our SOT colleagues a memorial to our close friend and colleague, Dr. Thomas W. Kensler, who passed away from a hiking accident on Mt. Blanc, France, on July 11, 2025, at the age of 76.
Dr. Kensler was born in New York City in 1948, the son of Charles J. Kensler and Elizabeth B. K. Williams. He grew up in Lexington, Massachusetts. Tom earned his AB in biology from Hamilton College and then went on to receive his PhD in toxicological sciences from the Massachusetts Institute of Technology in 1976, in the laboratory of Dr. Gerald Wogan, a legend in aflatoxin research. Tom completed postdoctoral training at the McArdle Laboratory for Cancer Research at the University of Wisconsin and then at the National Cancer Institute in cancer therapeutics. He was recruited to the faculty of the Johns Hopkins Bloomberg School of Public Health in 1980. Tom spent 30 years at Hopkins before he and his wife, Dr. Nancy Davidson, moved to the University of Pittsburgh in 2010 (he maintained his appointment and collaborations with his colleagues at the Johns Hopkins Bloomberg School of Public Health). In 2017, he and Dr. Davidson moved to Seattle, where Nancy was appointed as President and Executive Director of the Seattle Cancer Care Alliance and Senior Vice President at the Fred Hutchinson Cancer Research Center, and Tom continued his research in the Public Health Sciences Division for 7 more years, retiring in 2024.
Dr. Kensler was a leader in several related areas in toxicology, including the toxicology of aflatoxins and the molecular understanding of antioxidant response pathways. Over his nearly 50 years of research, Dr. Kensler published 400+ peer-reviewed research papers, and ~100 book chapters and reviews. His research has been cited by others over 45,000 times, giving him an "H-Index" of 109, which is remarkable.
Tom commented to one of us many years ago, “My goal is to have an H-factor higher than my age when I die.” He more than made that goal! This is remarkable evidence of the scientific impact that Dr. Kensler has had in toxicology and cancer prevention research.
Tom was a major contributor to the field of cancer chemoprevention, with much of his work focused on novel approaches to dietary modulation of aflatoxin biotransformation. His contributions in the area, focused on the prevention of dietary aflatoxin-induced liver cancer, were exceptional, yet only 25% of his research publications were related to aflatoxins. He made enormous contributions in the broader (albeit related) area of redox biology, with a focus on understanding how certain vegetable components in the diet can modify gene expression of antioxidant pathways that help protect against oxidative stress. His research was both fundamental and directly applicable to real-world cancer prevention. His remarkable studies on the Keap1-Nrf2 antioxidant pathway and its modification by dithiolthiones (including sulforaphane found in broccoli and other cruciferous vegetables) led the way for direct human intervention studies in populations at increased risk for certain cancers.
Tom was an active member of SOT since 1980, attending nearly all the last 50+ SOT meetings. In 1995, he was elected to serve as Vice President, and then served as President, of the Carcinogenesis Specialty Section. From 2001 to 2005, he served on the SOT Scientific Program Committee and Chaired the SOT Disease Prevention Task Force in 2011-2012. He received the distinguished SOT Translational Impact Award in 2009. He was also very active in the American Association for Cancer Research (AACR) and received the AACR Award for Research Excellence in Cancer Epidemiology and Prevention in 2007.
In addition to his contributions to scientific societies, Tom served on nearly a dozen editorial boards, including Chemical Research in Toxicology and the Journal of Biological Chemistry. He was a tireless contributor to advisory boards for over a dozen university toxicology and/or cancer research programs across the country.
His research had global impact and was greatly appreciated in China. In 2011, Tom received a National Friendship Award, Beijing, People’s Republic of China, which is the highest award for foreign civilians and was made an honorary Professor, Nantong Tumor Institute, Nantong, China, in 2015.
In addition to his remarkable contributions to cancer prevention research, Tom was an outstanding mentor and educator. Over his 40+ years in academia, he served as faculty advisor/mentor for 28 doctoral students, 8 master’s students, and 16 postdoctoral fellows. But his mentorship and influence on other scientists extends well beyond the dozens of graduate students and postdocs that he directly mentored. For example, Dr. Donna Zhang, Professor in pharmacology and toxicology at the University of Arizona, was quoted in Dr. Kensler’s obituary in the Baltimore Sun: “His quiet brilliance, deep integrity, and unwavering generosity shaped not only the field of redox biology but also my own journey in science." As a demonstration of Tom’s drive to be a good mentor, one of our toxicology colleagues shared the following story: “I recall being with him at Hopkins as a visiting scientist. I attended a student seminar being presented by one of his students. Tom was really grilling the students to a point that it was difficult to see why he was being so critical. Patricia Egner [Tom’s senior lab tech] explained afterward that Tom wanted his students to go out into the world, be respected from the first sentence they shared, be accurate with their sharing, and think about the bigger issues. It was better that life was uncomfortable for them in a safe environment (the seminar) than when they were out in the real world.”
He will be greatly missed as a dear friend and colleague, but we find solace that his extensive research and teaching contributions in toxicology and cancer prevention research will continue to inspire new research and save lives and that as tragic as his accident was, he departed doing something he loved.
Tom is survived by his wife of 43 years, Nancy E. Davidson; son Kevin H. Kensler; daughter Caroline B. Kensler; and son-in-law Nikolas F. Iubel; brother-in-law and sister-in-law David L. Davidson and Kathy Reigstad; nephews David M. Davidson and Keith L. Davidson; and stepsisters Aimée Margolis and Nadia Margolis.
We would like to express our deep gratitude to Dr. Nancy Davidson for her 50+ years of devotion to Dr. Kensler’s personal and professional development and to all of Tom’s trainees, who provided him with the motivation to continue his research.
This tribute to Tom is based on an obituary publication in a special issue of the journal Toxins, devoted to Dr. Groopman’s lifetime contributions to aflatoxin research (in press). See also the American Association for Cancer Research obituary describing Dr. Kensler’s amazing contributions in the field of cancer prevention research.