KLK3 and prostate cancer: In addition, a study on data from the Dominican Republic Demographic and Health Survey (DRDHS, 2013), on a population of 3,272 men aged 40 to 60 years old, found that 30.6% of them had been screened preventively for prostate cancer (prostate-specific antigen testing or digital rectal examination) at some point in their lifetimes.14