Pesticides linked to Prostate Cancer

Summary: Prostate Cancer incidence and mortality associated to pesticide exposure

The results of a study published in Nov. 2024 provide evidence of a strong potential link between 22 pesticides and higher prostate cancer incidence rate. Four of those agrochemicals were also associated with a higher mortality risk.

Prostate Cancer and agchems

Worldwide, prostate cancer is the second most frequent cancer, followed by lung cancer. It is the most common form of cancer in men in 118 countries around the globe.

Prostate cancer (PC) is diagnosed in around 1.5 million men each year, and its incidence rate ranges from 3 per every 100,000 men in Bhutan and Yemen, to 100 per every 100,000 men in Barbados, Martinique, Guadeloupe, Sweden, Norway, and Lithuania.

However, the mortality rate is highest in sub-Saharan Africa and in the Caribbean while it is lowest in Saudi Arabia, India, China, and Japan.

These disparities reflect two factors: a higher screening rate with PSA or (prostate-specific antigen) testing that detects prostate cancer earlier, and is common in more developed regions, and genetic variants in certain ethnic groups like Western Africa, that predispose men there to a higher rate of PC. (2)

The role of pesticides

There are other risk factors involved other than genetics, and a recent study by Sorensen et al. published on Nov. 04, 2024 (1), investigated the potential role of agricultural pesticides in the incidence rate and mortality of prostate cancer.

The authors analyzed the data for 295 pesticides and the quantity in kg per county applied in each county across the U.S. for the period 1997-2001 amd 2002-2006. They then analyzed the data for prostate cancer cases outcome between 2001 and 2015, and 2016-2020.

They found that 22 pesticides "showed consistent, direct associations with prostate cancer incidence" in both groups.

The group of 22 pesticides linked to prostate cancer included 10 herbicides, several fungicides and insecticides, and a soil fumigant.

They also pinpointed 4 pesticides that were associated not only with the incidence, but with higher prostate cancer mortality.

These four pesticides linked to a higher mortality risk are listed below:

• trifluralin (herbicide)
• cloransulam-methyl (herbicide)
• diflufenzopyr (herbicide)
• thiamethoxam (insecticide)

Surprisingly, the Environmental Protection Agency (EPA) has only classified trifluralin as a "possible human carcinogen." The other three agrochemicals were either considered "not likely to be carcinogenic" or have evidence of "non-carcinogenicity."

The paper concludes that:

The results of this study suggest a potential link between certain pesticides and increased prostate cancer incidence and mortality. These findings warrant further investigation of these specific pesticides to confirm their role in prostate cancer risk and to develop potential public health interventions. Sorensen et al. (2024) (1)

Agrochemicals pose risks to our health

There have been previous studies hinting at a link between pesticide exposure and risk of aggressive prostate cancer among men who applied them, and some have discovered a genetic predisposition in some men. (3),(4)

It should be noted that the European Union The EU banned trifluralin in 2008 because of its toxic effects on aquatic life. Cloransulam-methyl is not approved for use within the European Area either.

The insecticide thiamethoxam is a neonicotinoids and was banned for outdoor agricultural use in the UK and the EU in 2018 as it killed off bees.

References and Further Reading

(1) Soerensen SJC, Lim DS, Montez-Rath ME, et al., (2024). Pesticides and prostate cancer incidence and mortality: an environment-wide association study. Cancer. 2024; 1-9. doi:10.1002/cncr.35572

(2) Sandy McDowell, (2024). Cancer in Men: Prostate Cancer is #1 for 118 Countries Globally. American Cancer Society September 27, 2024. Accessed Nov. 22, 2024

(3) Pardo LA, Beane Freeman LE, Lerro CC, Andreotti G, Hofmann JN, Parks CG, Sandler DP, Lubin JH, Blair A, Koutros S. , (2020). Pesticide exposure and risk of aggressive prostate cancer among private pesticide applicators. Environ Health. 2020 Mar 5;19(1):30. doi: 10.1186/s12940-020-00583-0. PMID: 32138787

(4) Michael C. R. Alavanja et al., (2020). Use of Agricultural Pesticides and Prostate Cancer Risk in the Agricultural Health Study Cohort. American Journal of Epidemiology, Volume 157, Issue 9, 1 May 2003, Pages 800–814, https://doi.org/10.1093/aje/kwg040