There was a good question asked on a prior entry:
Robotic Surgery Blog: Is Prostate Cancer Transmissible?: “Would you please comment on whether there is a connection between sexual activity and elevated PSA. Also, why would test results given to a patient not break down PSA into free and that with protein. Thank you.”
PSA can be done in many ways. Most often urologists including myself only order the total PSA, not the free and total test. If the free is ordered I usually do not give it to patients unless they ask. In general a low number (under 10%) gives you a higher chance of having cancer and a high number (over 25%) gives you a lower chance. Most patients would not understand the nuances involved in reading this test.
As for sexual intercourse, I do not think it causes a major jump in PSA. Patients who have intercourse the day before the test may have a slightly higher PSA value. When the studies were done to evaluate PSA values and risk of cancer patients were not asked to abstain from intercourse. Therefore I do not ask patients to modify their behavior.