It should be stressed that the PSA test is not conclusive by itself in diagnosing prostate cancer. No treatment decision should ever be made on the basis of the PSA value by itself; however, an elevated PSA reading may suggest the need for further laboratory tests.he most common is the enlargement of the prostate gland that occurs with BPH. Infections and traumas such as a biopsy or even an overly vigorous digital rectal exam can sometimes increase PSA levels. Ejaculation (orgasm) can elevate PSA for as long as 48 hours.