what kind of lung cancer does your friend have? I know the hpv virus is responsible for some oral cancers(tongue, tonsil etc), as well as cervical, penile and rectal cancer. I believe it affects the squamous cells. I've never heard of a link between lung cancer and hpv, but i know that oral cancer caused by hpv, if at an advanced stage, can metastasize to the lungs. So I guess I understand your concern. Im sorry your friend is going through this. It sucks regardless of what causes it.