Study reveals link between many pesticides and prostate cancer

Researchers have identified 22 pesticides consistently linked to prostate cancer incidence in the U.S., with four pesticides also having links to prostate cancer mortality. The results of the study are published in the journal Cancer.

To assess the association of 295 pesticides with prostate cancer, the researchers conducted a U.S.-wide environmental dependency study, using a lag time between exposure and prostate cancer incidence of 10-18 years to account for the slow-growth nature of most prostate cancers. Data for years 1997-2001 were analyzed from the perspective of pesticide use, and data for years 2011-2015 were analyzed from the perspective of prostate cancer outcomes. Similarly, years 2002-2006 were analyzed for pesticide use and years 2016-2020 were analyzed for outcomes.

Among the 22 pesticides that showed a consistent direct association with prostate cancer incidence in both temporal analyses were three that had been previously linked to prostate cancer, including the pesticide 2,4D, one of the most commonly used pesticides in the United States. Among the 19 candidate pesticides not previously linked to prostate cancer were 10 herbicides, several fungicides and insecticides, and a soil fumigant.

Four pesticides that have been linked to prostate cancer incidence were also linked to prostate cancer mortality: three herbicides (trifluralin, cloransulam-methyl, and diflufenzopyr) and one insecticide (thiamethoxam). Only trifluralin is classified by the Environmental Protection Agency as a “possible human carcinogen,” while the other three herbicides are considered “unlikely carcinogens” or have evidence of “no carcinogenicity.”

“This study demonstrates the importance of examining environmental exposures, such as pesticide use, to potentially explain some of the geographic differences we see in prostate cancer incidence and mortality in different regions,” said lead study author Simon John Christoph Soerensen, a physician at Stanford University School of Medicine. – With these data, we can advance our efforts to identify risk factors for prostate cancer and reduce the number of men affected by the disease.”