University of Kentucky receives Department of Defense grant for lung cancer study

University of KentuckySep 23 2011

The University of Kentucky's Dr. Susanne Arnold and colleagues were awarded a grant by the Department of Defense to study potential environmental reasons for the high lung cancer rates in Eastern Kentucky. The grant is for $1.43 million over three years and the study began on Sept. 15.

Kentucky has the highest lung cancer rates in the nation, but counties in the southeastern portion of the state - those in the 5th Congressional District - have an exceptionally high incidence of lung cancer. Data from the Kentucky Cancer Registry, a Surveillance, Epidemiology and End Result (SEER) site, revealed that the age-adjusted incidence rate for lung cancer in Appalachian Kentucky from 2003-2007 was 115.2 cases per 100,000 residents, compared to 61.6 cases per 100,000 residents nationally.

A "high" lung cancer rate is defined as more than 101.6 cases per 100,000 residents. By this definition, 83 percent of the counties in the 5th District have high rates, compared to 38 percent for the rest of Kentucky.

Tobacco use is the leading cause of lung cancer, and 25 percent of Kentuckians smoke, compared to the 21 percent of people nationally. But smoking on its own doesn't explain the discrepancy between southeastern Kentucky and the rest of the nation, said Arnold.

"We know that tobacco is the number one cause of lung cancer, but that isn't the only factor causing the high cancer burden for southeastern Kentucky," Arnold says. "So we started to look for other possible reasons. Could environmental carcinogens play a role? That's what this grant will allow us to investigate."

Arnold says the idea for the lung cancer study came about because of preliminary data from a study of colon cancer patients in Appalachia. The study examined toenail clippings from patients to assess their exposure to trace elements. Appalachian colon cancer patients showed significantly higher amounts of arsenic, chromium and nickel than non-Appalachian patients, suggesting that they had been exposed to these trace elements more extensively.

Although trace amounts of metals (such as iron) are necessary for the body's normal functions, prolonged exposure to trace elements including arsenic, beryllium, cadmium, cobalt, chromium, nickel and vanadium has been linked to several types of cancer - including lung cancer. These trace elements are known to promote carcinogenesis by increasing oxidative stress, inflammation and DNA damage, and reduced DNA repair efficiency.

There are several potential sources for trace element exposure in southeastern Kentucky. Residents could be exposed through their water source, their soil, the local food sources they eat, or in other unknown ways.

Arnold says her study will define age- and gender-matched cancerous and non-cancerous residents. Each participant will be asked to fill out a questionnaire about his or her smoking habits. Researchers will determine the amount of exposure to trace elements by taking samples of residents' toenails, hair, urine and blood. To determine the source of the exposure, they'll also collect samples of water and soil from the home. The biological and environmental samples generated from this study will also be made available to other researchers to use for other studies on health in Appalachia.

This project is also partnering with Kentucky Homeplace, an advocacy organization known and trusted throughout southeastern Kentucky. The organization provides access to medical, social, and environmental services for the citizens of the Commonwealth.

"We are extremely lucky to have this outstanding organization helping with this important initiative," Arnold said. "They will play a crucial role in helping us collect our data."

Arnold also spearheads the Marty Driesler 5th District Cancer Project, a rural health care initiative dedicated to increasing the survival rates for people with deadly cancers through out Kentucky's 5th Congressional District. The project encourages partnerships of the Markey Cancer Center and community health care providers and facilities to establish a community program for early detection, prevention, and treatment of lung, liver and esophageal cancer.

"As an eighth-generation Kentuckian, this work is really personal for me," Arnold said. "I was raised by a doctor who committed his life to research in Kentucky because he really believed it was important for us to help solve Kentucky's problems. And now I am a doctor that takes care of lung cancer in Kentucky. I feel like it's our job to be a champion for the people of Appalachia. I hope this study will help us to understand the epidemic that is ravaging southeastern Kentucky and begin to find solutions to this devastating problem."