In Memoriam: Isaiah J. Fidler

Isaiah J. Fidler, DVM, PhD, FAACR, a pioneer in the field of cancer metastasis and a Past President of the AACR, died May 8, 2020, at the age of 83.

Fidler, known to his admiring colleagues and friends as “Josh,” was born in 1936 in Jerusalem, Israel. He earned a doctorate in veterinary medicine in 1963 from Oklahoma State University and a PhD in human pathology from the University of Pennsylvania School of Medicine in 1970. 

Fidler held faculty positions at the University of Pennsylvania, then joined the Frederick Cancer Research Facility at the National Cancer Institute (NCI), National Institutes of Health, as head of the Biology of Metastasis Section in 1975. In 1979, he was appointed director of the NCI’s Cancer Metastasis and Treatment Laboratory. 

In 1983, Fidler joined The University of Texas MD Anderson Cancer Center (MDACC) as professor and founding chair of the Department of Cancer Biology, a department he chaired until 2008. In 1998, he was named director of the Cancer Metastasis Research Center and Metastasis Research Laboratory. He also held the R. E. “Bob” Smith Distinguished Chair in Cell Biology.  In 2019, he retired from MDACC and was given the distinguished title of professor emeritus.

Fidler focused his research on cancer metastasis, and his brilliant insights had a transformative effect on numerous scientific areas, including tumor biology, cancer drug development, and treatment. Among his most important findings were that tumors are composed of heterogeneous cell populations, and that specific cell types within those populations have metastatic potential. Such findings have suggested that cancer therapies should be geared toward eliminating these small subsets of cells, thereby confining a tumor within its primary organ site and maximizing the patient’s opportunity for survival. Later in his career, Fidler’s research focused on understanding the basis of brain metastasis in a variety of cancers.

Fidler served as President of the AACR for the 1984-1985 term. Margaret Foti, PhD, MD (hc), chief executive officer of the AACR, reflected on the fact that Fidler was, at that time, the youngest President ever to be elected to this prestigious post. 

“Josh was the third President I had the privilege of serving, and I learned so much from him,” Foti said. “I will always remember him not only for his amazing intellect and dedication to the cause, but also for his personal strength, kindness, and engaging personality.” 

In addition to serving as AACR President, Fidler was a member of the AACR Board of Directors from 1982 to 1985. He was an associate editor of Cancer Research from 1978 to 1986, and an associate editor of Clinical Cancer Research from 1995 to 1998. He served as a member of the Gertrude B. Elion Cancer Research Award Committee from 1998 to 1999; the AACR-G.H.A. Clowes Memorial Award Committee from 2001 to 2002; and the Research Grant Review Committee from 2008 to 2010.  

Fidler received the AACR-G.H.A. Clowes Memorial Award in 1988 for his seminal discoveries in tumor biology and cancer metastasis.  He was inducted as a Fellow of the AACR Academy in 2013 and received the AACR Margaret Foti Award for Leadership and Extraordinary Achievements in Cancer Research in 2018.  

Among many other career honors and awards, Fidler won the Ernst W. Bertner Memorial Award in 1983; the Raymond Bourgine Prize as well as the City of Paris Gold Medal in 1993; the Outstanding Investigator Award from the National Cancer Institute in 1987 and 1995; the WHO Gold Medal for Biological Sciences in 1997; the Bristol-Myers Squibb Award for Distinguished Achievement in Cancer Research in 1999; the E. G. Rosenblatt Award for Scientific Achievement from the USA Israel Cancer Association in 2001; the Outstanding SPORE Investigator Award from the NCI in 2003; the Charles A. LeMaistre, MD, Outstanding Achievement Award in 2004; the MD Anderson President’s Award in 2007, along with his wife, Margaret Kripke, PhD; Nature Publishing Group’s Lifetime Achievement Award in 2010; the American Cancer Society Medal of Honor for Basic Research in 2013; and the Gold-Headed Cane Award from the American Society for Investigative Pathology in 2016. He was a fellow of the American Association for the Advancement of Science.  

Over the course of his outstanding career, Fidler mentored numerous students and was widely praised for his skill in guiding and motivating graduate students, postdoctoral fellows, and clinical fellows.

“It is impossible to capture in a short remark the full impact that Josh Fidler has had on cancer research and on his devoted colleagues and friends,” Foti said. “He will always be remembered for his ability to stimulate new thinking about the origin and progression of cancer and for his profound personal drive to cure human cancer. Josh will be sorely missed by all of us in the world cancer research community.”