By Heather Mayer Irvine

Payroll people, divert your eyes. Khadijah Mitchell, professor and geneticist in the biology department, says she’d work for free.

“It’s what I was put on this earth to do,” she says of her cancer research. “People pay me to come here every day, but I would do this work for free. I love it.”

Mitchell’s passion, enthusiasm, and personality can barely be contained in her second-floor Kunkel Hall office. The professor’s open-door policy invites a line of students who want to discuss class, theses, research, and even their personal issues.

Mitchell, who came to Lafayette in July 2017, notes the importance of involving
her community in her work.

“I tell my students that it’s not enough for science to stay in the walls of the lab,” she says. “We’ve got to share our knowledge to educate and help others.”

The sign that hangs behind Mitchell’s desk, a quote attributed to Benjamin Franklin, emphasizes the power of community involvement: “Tell me and I forget. Teach me and I remember. Involve me and I will learn.” At the bottom it says, “The Mitchell Lab.”

Mitchell has many areas of focus, including lung and kidney cancer research. This is what she’s currently working on.

Individualized Treatment

The ultimate goal of Mitchell’s work is to create cancer therapies targeted to an individual’s needs. This is called precision medicine, which considers genetic, environmental, and lifestyle factors. For example, as Mitchell has seen, tumor growth can be caused by genetic changes, and what happens in one person’s cancer may not be the same as someone else’s even if they have the same type of cancer.

Tumor Differences

Mitchell and her research team have found that lung and kidney tumors in African American and European American patients are molecularly different. In other words, certain genes are turned off (or on) in a tumor in an African American patient while those same genes are turned on (or off) in a tumor in a European American patient.

What’s more is lung cancer tumors in African Americans are more aggressive. They’re more likely to spread, making them harder to treat.

“It’s the same disease, but there are features of the disease that make it so these patients have poorer health outcomes,” says Mitchell.

She has taken cell lines from cancer tumors and is testing different variables—types of cigarettes, amounts of carcinogens, lengths of exposure—to better determine what causes these differences.

In Your Genes?

As a geneticist, Mitchell is trying to understand how a person’s genes may affect his or her risk for cancer. She has been researching why African Americans have higher incidences of lung and kidney cancers compared to European Americans.

In patients who smoke, for example, African Americans experience higher lung cancer rates than European Americans, and the pattern is the same in lung cancer patients who don’t smoke.

Because other factors—age, socioeconomic status, type of cancer—are the same across ethnic groups, Mitchell is looking at what genes might contribute to this disparity.

In her lung cancer research, Mitchell is studying the genes that process menthol, cigarette of choice in African Americans thanks to Joe Camel marketing, she says.

“African Americans with lung cancer have less of the protein that metabolizes tobacco, and if that protein gets rid of carcinogens, that could possibly explain the difference in incidence rate,” she explains.

Race May Be a Social Construct, but It’s Also Based on Genetics

When considering patient demographics, most researchers ask subjects to self-report their race: African American, Caucasian, Hispanic, Asian American, Native American. But Mitchell notes the importance of including biological measures of a population, which can be done via blood work.

“Someone may present as African American but their genetics show they’re only 15 percent [African American],” she says. “It’s artificial to use [self-reported] race alone.”

In knowing patients’ genetics, Mitchell can better understand the differences in their cancers.

Radon Education and Outreach

Second only to smoking, radon exposure is the most common cause of lung cancer. Here in the Lehigh Valley, radon levels are significantly higher than in other parts of the country. In October 2016, the highest level of radon in Pennsylvania was recorded in Center Valley, at 6,176 picocuries per liter, more than 1,500 times higher than the recommended limit -of 4 pCi/L.

The highest level in the country was just over the Pennsylvania–New Jersey border in Clinton, N.J.: 7,000 picocuries per liter. Those levels put a person at the same risk for lung cancer as if he or she smoked 350 packs of cigarettes a day.

Mitchell is looking at lung cancer rates in Lehigh, Carbon, and Northampton counties to determine vulnerable populations. From there, she and her team will look at radon levels by ZIP code within those counties, which will help drive educational and awareness programs.

“We want to see if the incidence rates track with particular ZIP codes and radon levels,” she says. “By doing this work right in our own backyard, we’re making an impact in the immediate community.”