Researchers Study Causes of Malignancy

The South is known for many things – hot, steamy summers, iced tea laced with sugar and friendly people with a tendency to welcome strangers. But beneath the veneer of Southern hospitality and gracious living lurks a silent killer – cancer. Vanderbilt-Ingram Cancer Center researchers have their own name for the southern region of the United States – The Cancer Belt.

Brain cancer is one of the most alarming malignancies disproportionately affecting people who live in this cancer hot-spot. Glioma, also known as glioblastoma, is lethal. Ninety-five percent of patients die within two years of diagnosis.

“When you look at a map of brain cancer incidence in the United States the Southeast just lights up in red,” said Reid Thompson, M.D., associate professor and vice-chair of the Department of Neurological Surgery. “When we found this hot-spot on the National Cancer Institute’s mortality maps we realized something unusual is going on in this region.”

Thompson and co-investigator Kathleen Egan, M.P.H., Sc.D., formerly of Vanderbilt-Ingram but now on faculty at the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., have launched a study to find clues that may explain this southern brain cancer cluster. Vanderbilt-Ingram, which sits squarely in the center of the Cancer Belt, is enrolling as many as 1,000 patients in the study with the help of four other cancer centers.

“We’re asking patients about their diets, possible job-related exposure to cancer-causing chemicals, and we’re collecting DNA samples,” explained Thompson. “We know there are some genetic markers that are linked to other forms of cancer and they may play a role in brain cancer, as well.”

Brain cancer isn’t the only cancer taking an unusual toll on Southern populations. Topping the list is lung cancer. Despite decades of warnings about the dangers of cigarette smoking, Southerners continue to smoke more than individuals in other regions of the country.

But it is less easy to determine why people living in the South are developing many other types of cancer at higher rates than folks who live elsewhere. And it doesn’t explain why African-Americans are more likely to develop some forms of cancer and are more likely to die from the disease.

So William Blot, Ph.D., professor of Medicine, is leading the Southern Community Cohort Study (SCCS), the largest epidemiologic study in history to explore why the South has become the Cancer Belt and why African-Americans experience higher rates of many types of cancer. Starting with a $28 million grant from the National Cancer Institute, the SCCS hopes to recruit 90,000 people in 12 Southern states to learn about their lifestyles, their family medical histories and their risk factors for cancer and other serious diseases. Two-thirds of the participants will be African-American and many are from rural areas. Nearly 60,000 people already have enrolled.