World Trade Center (WTC) responders with prostate cancer showed signs that exposure to dust from the World Trade Center site had activated chronic inflammation in their prostates, which may have contributed to their cancer, according to a study by Mount Sinai researchers in Molecular Cancer Research in June.

Inflammation has long been considered an important factor in prostate cancer progression. Researchers looked at the inflammatory and immune systems of World Trade Center responders to help prevent new prostate cancer cases in that group and to understand how other large-scale environmental exposures to multiple carcinogens may develop into cancer.

This is the first study of people who were exposed to the WTC dust and who subsequently developed prostate cancer. This research and further study of the expression of genes and pathways in other patients whose environmental exposures caused inflammation could lead to clinical trials that offer anti-inflammatory or immune-targeted therapies in similar cases.

“World Trade Center responders show an overall increase in cancer incidence, and specifically of certain cancer types such as prostate cancer,” said Emanuela Taioli, MD, PhD, director of the Institute for Translational Epidemiology at the Icahn School of Medicine at Mount Sinai and associate director for population science at The Tisch Cancer Institute. “It is important to address the reasons why this is happening in order to prevent new cases in this aging cohort. Our findings represent the first link between exposure to World Trade Center dust and prostate cancer.”

This work pairs data from first responders and from a study of rats exposed to actual dust from Ground Zero. The dust samples, which contain metals and organic compounds such as polycyclic aromatic hydrocarbons and polychlorinated biphenyl, are unique because they are the only existing samples taken on September 11, 2001. All other dust samples were collected after a significant storm on September 14, 2001.

Both the human and rat prostate cancer tissues show an increase in cells that indicate inflammation, specifically immune cells called T helper cells. Studies of the rat tissue and prostate cancer tissue samples taken from responders indicated to the Mount Sinai researchers that chronic inflammation started occurring in the prostate after exposure to the World Trade Center dust, and that inflammation may have contributed to prostate cancer.

“Several years ago, I saw a first responder in his 40s who began having symptoms of prostatitis, a painful condition that involves inflammation of the prostate, soon after exposure to the World Trade Center dust,” said William Oh, MD, chief of the division of hematology and medical oncology at the Icahn School of Medicine at Mount Sinai and deputy director at The Tisch Cancer Institute. “He ultimately developed a high-grade prostate cancer several years later. It suggested to me that there might be a link between his exposure and cancer, but I knew that I would need to examine it systematically.”

This study was sponsored by grants from the US Centers for Disease Control and Prevention, the National Institute for Occupational Safety and Health, the National Institutes of Health, and the National Institute of Environmental Health Sciences.