From Toads to Tumors

Epidemiologist Preetha Rajaraman ’94 examines why some people are more susceptible to brain cancer than others.

By Romel Hernandez

Preetha Rajaraman arrived at Reed expecting to major in the humanities—literature and theatre. “I didn’t think of myself as much of a scientist,” she says. 

But courses with professors such as Arthur Glasfeld [chemistry 1989–], David Griffiths [physics 1978–2009], Steve Black [biology 1989–2012], and Bob Kaplan [biology 1983–] changed her mind. “That’s when I decided, ‘Maybe this could be my path.’”

Those classes started Preetha down a career path she could never have anticipated, taking her from a game reserve in Botswana to a research lab in Washington, D.C. Today she is a noted epidemiologist for the National Cancer Institute investigating the risk factors of brain cancer.

Preetha’s research is aimed at understanding how genetic variations make some people more susceptible to environmental factors (e.g., smoking cigarettes) linked to cancer. Her work ultimately may point the way to preventive strategies—reducing children’s exposure to the ionizing radiation in x-rays, for example—and may even lead to breakthroughs in chemotherapy treatment.

Raised in Africa by Indian parents, Preetha attended the Maru-a-Pula international school in Botswana. As a high schooler she had never heard of Reed until two fellow students went there. They reported back, touting the college’s academics, so she took a chance on applying. She was soon traveling across the world to Portland. And while she found right away that Reed lived up to its reputation for intellectual rigor, she was surprised by its freewheeling atmosphere. “At Reed, there is no one way to be,” she says. “You are accepted, and students are interested in who you are, where you come from.

She thrived at Reed. Mentored by Kaplan, she got the opportunity to travel on his summer student trek to the jungles of South Korea in 1993 to study the Asian fire-bellied toad and eventually wrote her thesis on the mating calls of that particular amphibian.

After graduating with a degree in biology and a plan to work with wildlife, she deferred her admission to the Yale School of Forestry to spend time at the Gaborone Game Reserve in Botswana. And while she enjoyed working with animals (the reserve is known for its diverse bird species, as well as an assortment of wildebeest, antelope, etc.), a stint at Botswana’s Department of Health, where she analyzed health statistics, changed her course. 

Making a choice between studying animals and humans, she opted for the latter. Instead of going to Yale, she earned a master’s degree in environmental health at the University of Washington and a PhD in epidemiology at John Hopkins. 

Joining the National Institute of Health’s National Cancer Institute as a predoctoral fellow in 2001, Preetha studied the effects of lead exposure on brain tumors. Her more recent work has focused on the carcinogenic effects of early exposure to radiation. She was drawn to investigate brain tumors, she says, because “they had been studied for so long, yet so little was known about them.” The past decade of research, she notes, has seen huge strides in understanding the causes and improving the treatment of brain cancer.

At the NCI she is known as a relentless worker, unafraid to tackle daunting challenges, whether that has meant plowing through a mountain of data on exposure to lead or bringing together scientists to collaborate on a study of glioma, a deadly type of brain cancer. “She has launched pathbreaking studies that seemed improbable, if not impossible, until she accomplished them—evidence of her perseverance,” says Patricia Hartge, deputy director of the NCI’s epidemiology and biostatistcs program. “Like every other scientist who works with Preetha, I recognize her sharp intellect, focus on public health, and high standards of integrity. She is justly proud of Reed, and Reed can certainly be proud of her.”


These images pinpoint a low-grade glioma, a tumor that arises in the glial cells of the brain.

Last year, her career took another detour, this time to India. Her husband was working as an economist in the country, and she was able to secure a job in New Delhi. As the NCI’s director of South Asian programs, the move shifts her focus from “very nuts-and-bolts research, which I truly love,” to developing international research priorities and partnerships. She calls the move “a leap of faith,” noting that India is brimming with potential in cancer research.

She continues to spend about half her time on her own research, however, and says she looks forward to resuming that work full time in the future. For now she’s enjoying her latest adventure, working abroad and raising her three children, ages 2, 8, and 11. 

“India forces you to grow up in many ways,” she says, “and sometimes it’s challenging, and sometimes it’s really fun.” Among the challenges she has undertaken over the past year is learning to speak Hindi (her first language is English). Taking language instruction has renewed her appreciation of the remarkable power of the organ she has spent so many years studying: “You realize that your brain is still so plastic, and you can always learn something completely new—at any age!”