KLK3 and prostate carcinoma: A large-scale population-based trial completed in 2006, The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, found that men undergoing annual PSA and DRE screening had the same rate of deaths from disease as those in the control group while those in the screened group had a higher incidence of prostate cancer [3]. The argument against screening and aggressive treatment in those with positive screenings lies in the natural history of this disease process, which can be indolent; many men may die with prostate cancer without ever treating it or knowing their diagnosis [4].