Health Effects of Per- and Polyfluoroalkyl Substances

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?