How the perseverance of Dr. Sarah Stewart turned a skeptical idea into funded research

Dr. Sarah Elizabeth Stewart was a Mexican-American scientist whose persistence and perseverance transformed the viral etiology of cancer from a dubious idea to a legitimate, mainstream field of research. Her road to success, however, was anything but straightforward.

Biography

Born in Jalisco, Mexico, in 1905 to an American father and Mexican mother, Stewart moved to the United States as a child to escape the Mexican Revolution. She attended New Mexico State University where in 1927 she earned a degree in home economics, one of the best of the limited options available to women at that time. Because this degree used the same courses as science degrees for men, Stewart received the necessary background to clinch a fellowship offer from the University of Massachusetts, Amherst, earning a master’s degree in microbiology in 1930. She then moved to Fort Collins, CO, where she became the first bacteriologist at the Colorado Experimental Station, studying nitrogen-fixing bacteria. Uninterested in this topic, however, she decided to pursue a PhD.

During her PhD studies at the University of Chicago, Stewart served as an unpaid research assistant to another female scientist at the National Institutes of Health (NIH), studying anaerobic bacteria. She obtained her PhD in 1939 but eventually lost interest in anaerobic bacteria, so in 1944 Stewart requested support to study the link between viruses and cancer. However, the NIH and the National Cancer Institute (NCI) rejected her proposal. While the link between viruses and cancer wasn’t a new idea, it was one that was not accepted by the scientific community. Additionally, Stewart was told that she wasn’t qualified to pursue such a research program.

Undeterred, Stewart resigned from the NIH to pursue a medical degree so she could engage in cancer research. However, in 1944, women were prohibited from enrolling in American medical schools. Instead, Stewart took up a teaching position at Georgetown University School of Medicine, where she also audited medical courses until the School of Medicine officially opened medical training to women in 1947. In 1949, at the age of 39, Stewart became the first woman to earn a medical degree from Georgetown.

Dr. Sara Stewart

Returning to the NIH, Dr. Stewart’s desire to study viruses and cancer was again denied. Appointed medical director in the US Public Health Service Commissioned Corps after a brief position at a hospital in Staten Island, Dr. Stewart accepted a position at the NCI in 1951, finally gaining the leverage and resources necessary to study her passion.

Working with another female scientist, Bernice Eddy, Stewart built on the work of Polish-American scientist Ludwik Gross, demonstrating in 1957 that a virus could cause 20 different types of tumors in mice and could also cause tumors in other small mammals (although they wouldn’t officially call the tumor-causing agent a virus until the following year). After successfully culturing the virus in 1958, they named it the Stewart-Eddy polyomavirus. Their work was highlighted in Time Magazine in 1959, where NCI director John Heller was quoted as saying, “The hottest thing in cancer research is research on viruses as possible causes of cancer.”

Dr. Stewart eventually became the medical director of the NCI Laboratory of Oncology, where she studied the connection between cancer and other viruses such as Epstein-Barr, and in 1970 she became a full professor at Georgetown—the Medical School that had initially denied her enrollment in their medical degree program. She earned several other accolades throughout her hard-fought-for career, including the Federal Women’s Award presented by President Johnson in 1965. In an ironic stroke of fate, Stewart died in 1976 from the disease she fought so hard to study: cancer.

Dr. Stewart’s persistence paid off for herself and for the world at large. Not only did she manage to turn a skeptical idea into a well-funded research topic, but she also earned accolades and leadership positions from institutions and organizations that initially shunned her. But perhaps most importantly, her seminal work on the viral etiology of cancer led to an explosion of research into a topic that the scientific community had long struggled to accept. The development of the HPV vaccine to prevent cervical cancer—administered to millions since 2006—has been directly attributed to her persistence to convince the scientific community that the link between viruses and cancer is very real.

References

1. NIH National Cancer Institute (2020). Annual Plan and Budget Proposal for Fiscal Year 2020. https://www.cancer.gov/about-nci/budget/plan/2020-annual-plan-budget-proposal.pdf ; accessed October 10, 2023.
2. McNeill, L. The Woman Who Revealed the Missing Link Between Viruses and Cancer. Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/woman-who-revealed-missing-link-between-viruses-and-cancer-180972427/ ; accessed October 10, 2023.
3. Fulghieri, C. and Bloom, S. Sarah Elizabeth Stewart. Emerg Infect Dis 20, 893–895 (2014). 
4. Stewart, S. E., Eddy, B. E., Gochenour, A. M. et al. The induction of neoplasms with a substance released from mouse tumors by tissue culture. Virology 3, 380–400 (1957). 
5. Stewart, S. E., Eddy, B. E., and Borgese, N. Neoplasms in Mice Inoculated with a Tumor Agent Carried in Tissue Culture. JNCI 20, 1223–1243 (1958).
6. HPV Vaccine Facts. American Cancer Society. https://www.cancer.org/cancer/risk-prevention/hpv/hpv-vaccine-facts-and-fears.html#:~:text=More%20than%20270%20million%20doses,closely%20monitor%20HPV%20vaccine%20safety. ; accessed October 10, 2023.