Study links DDT exposure in the womb to testicular cancer

Men exposed in the womb to the pesticide dichlorodiphenyltrichloroethane (DDT) and its related compounds are more likely to develop testicular cancer, say researchers from Child Health and Development Studies (CHDS), Berkeley, CA.

The researchers say the study adds evidence that there may be an environmental link to the cancer, a hypothesis that they have suspected.

The CHDS enrolled 15,000 pregnant Kaiser Foundation Health Plan members in the San Francisco Bay area from 1959 to 1967, and many families participated in follow-up studies from early childhood through adolescence.

In the study, 15 sons who developed testicular cancer were compared with a control group of other CHDS sons who did not. The researchers compared blood samples of the mothers just after pregnancy-during DDT’s peak usage period in the U.S. in the 1960s. Researchers use the ratio of DDT to dichlorodiphenyldichloroethylene (DDE, the chemical DDT converts to in the body) as a measure of exposure. They found higher levels of DDT in cases than in the controls for a given level of DDE.

The study suggests a correlation between how fast mothers break down DDT into DDE and testicular cancer. The median age at which sons were diagnosed with the disease was 30 years.

Although the chemical has played an effective role in killing insects that carry malaria in places like Sub-Saharan Africa, "This study gives some insight about whether there may be a cost associated with its use, which would require further evaluation of its health effects in areas where it’s actively being used," said co-author Piera Cirillo of CHDS.

"This study is unique and valuable in being the first to be able to provide information about prenatal and early postnatal exposure in testicular cancer cases," said Shanna Swan, PhD, of the University of Rochester Medical Center, Rochester, NY, who was not involved with the study. "It is based on blood samples from a median of 30 years prior to diagnosis, and I don’t know of another study that has that capability."

Study results were published in the Archives of Environmental & Occupational Health (2010; 65:127-34).