CASE SCENARIO

K.H. is a 46-year-old man who presents to my clinic for evaluation of a painless testicular mass he first noticed a few weeks ago while showering. He is otherwise asymptomatic, including no fevers or penile discharge. He has a history of hyperlipidemia but no history of cancer. On physical examination, there is a 3-cm, nontender, firm mass on the right testicle. The left testicle appears normal, and there is no lymphadenopathy or abdominal mass. While discussing your concerns regarding malignancy and the need for further diagnostics, K.H. asks whether his occupation as a firefighter could be somehow related. He is currently employed as a civilian firefighter; during his previous military service as a firefighter, he reports extensive use of aqueous film-forming foams that contained per- and polyfluoroalkyl substances (PFAS) when extinguishing airport and military installation fires. In addition to treating my patient, how can I best answer his question about the relevance of PFAS in causing his condition?

COMMENTARY

PFAS are a class of chemicals that are widely used in industry and commonly found in the environment. There are thousands of different PFAS, but some have been studied more comprehensively than others (eg, perfluorooctanoic acid, perfluorooctanesulfonic acid, perfluorohexanesulfonic acid, perfluorodecanoic acid, perfluorononanoic acid). Of these, perfluorooctanoic acid and perfluorooctanesulfonic acid are more common in industrial use, although less often now because of industrial phaseout or regulation against their use worldwide.¹