We've recently done full health test of my dad  and observed that PSA is high . To revalidate it, we retested from different lab and this time it came less than previous. However, both time the figure is higher than 10. He is fit, non-alcoholic, non-smoker, regularly go for walking and cycling. Moreover, he doesn't have any symptoms like initiating urination, dribbling and staining while passing urination, bleeding etc.. and in our family too noone has past cancer history. Kindly provide your best advise. Thanks