Pinpointing reasons behind the dramatic increase in testicular cancer, now the most common malignant cancer among 15-to-35-year-old Caucasian men, is the focus of a five-year, $5.5 million National Cancer Institute (NCI) grant to Yale Public Health researcher Tongzhang Zheng.
Testicular cancer is increasing for unknown reasons and this study will provide important information on possible environmental, genetic and other risk factors," said Zheng, professor and head of the Division of Environmental Health Sciences in the Department of Epidemiology and Public Health at Yale School of Medicine.
Zheng will collaborate with researchers at Harvard School of Public Health and the Fred Hutchinson Cancer Research Center to conduct a population-based, case-control study on men in Connecticut and Massachusetts. The researchers will determine whether exposure to environmental factors such as environmental hormone disruptors increases the risk of testicular cancer. They will measure the levels of these environmental compounds in 800 patients with testicular cancer and in an equal number of unaffected control subjects.
Because so little is known about the potential environmental causes of testicular cancer, Zheng said, the team will collect and evaluate information on various major suspected risk factors, such as past medical history, history of hernia, venereal diseases, and any medication with androgens and other hormones. They will also examine lifetime occupational history, tobacco smoking, alcohol consumption and dietary information.
"Recent studies show that environmental exposures may affect development of testicular cancer," said Zheng. "Determining risk factors that lead to testicular cancer, however is complicated because genetic susceptibility may modify a person's risk from environmental exposures. We will try to assess the potential gene environment interaction on the manifestations of the disease."