Research reveals links between many pesticides and prostate cancer

Researchers have identified 22 pesticides consistently linked to prostate cancer incidence in the United States, with four of the pesticides also linked to prostate cancer mortality. The findings were published in Cancer.

To assess the county-level associations of 295 pesticides with prostate cancer across several counties in the United States, researchers conducted an environmental-wide association study, using a lag period between exposure and prostate cancer incidence of 10 to 18 years to account for the slow-growing nature of most prostate cancers. The years 1997–2001 were assessed for pesticide use and 2011–2015 for prostate cancer outcomes. Similarly, the years 2002–2006 were analyzed for pesticide use and the years 2016–2020 for the results.

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

Four pesticides linked to prostate cancer incidence were also linked mortality from prostate cancer: 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 are considered “probably not carcinogenic” or have evidence of “noncarcinogenicity.”

“This research demonstrates the importance of studying environmental exposures such as use of pesticidesto potentially explain some of the geographic variation we observe in prostate cancer incidence and deaths in the United States,” said lead author Simon John Christoph Soerensen, MD, of Stanford University School of Medicine.

‘By building on these findings we can further our efforts to find out risk factors for prostate cancer and working to reduce the number of men affected by this disease.”