Cancer epidemiologist Lifang Hou's father was a lifelong smoker, and she urged him to quit all through her medical training. He insisted that because his parents smoked for decades and died of natural causes, he was not at risk of cancer

"I kept telling him genetic makeup does not determine all your disease outcomes—it's also your environment and lifestyle," Hou says. "So now I'm focused on identifying biological evidence that genetics and environment work together."

This is Hou's research mission: to identify biological evidence of the interplay of genes and environment in cancer. What we eat, how much we exercise, where we live and how we handle stress—Hou says these are just some of the variables that interact with our genes in cancer development. And she intends to prove it.

Not precise enough

Precision medicine considers each's genetic and environmental factors to determine treatment strategies. Also known as personalized medicine, this field rejects the idea that one drug or treatment works for all patients. Hou says that approach does not go far enough.

"We have been applying all these precision medicine technologies to cancer treatment—making decisions about drugs and therapies based on a patient's unique profile," Hou says. "Now, we're trying to do the same for cancer prevention. Without precision prevention, we're just chasing after cancer, and we need to get ahead of it."

From patients to populations

Telomeres that shorten more quickly than usual might indicate a higher risk of future cancer. Credit: Northwestern University. About five years into her work as a physician, Hou realized that if she wanted to lead pathbreaking prevention efforts, she would have to think beyond the clinic.

"As a physician, I only dealt with individual patients, but I wanted to understand what was happening at a population level," Hou says. "I wanted to understand the causes of cancer development and help develop tools for early detection and prevention." 

Now, Hou is focused explicitly on cancer biomarkers — biological indicators of the disease—in blood. Blood-based biomarkers, she says, will allow for more straightforward, lower-cost tests that can be deployed in physicians' offices during routine check-ups. Equally important: These biomarkers are indisputable.

"We can not just say to policymakers, 'pesticides maybe can cause cancer,'" Hou says. "We have to bring the science along and show them the truth. And then we share our findings with the public."