Hi – I have heard that taking propecia may provide a false negative in some cases on a PSA test since DHT is lowered. Is it possible to have prostate cancer and not know it from a PSA test because propecia hid the true results?
Prostate Specific Antigen (PSA) test is a screebubg test for prostate cancer. It is a nonspecific screening tool for doctors to consider when evaluating a patient. PSA can be affected by many non-cancerous causes such as infection, benign elargement of the prostate (BPH), or even digital manipulation (during a rectal exam, for example). Finasteride is thought to reduce elevated PSA levels so we generally take a PSA baseline test for all men over 50 prior to starting the drug.
For further reading, the Dec 2005 Journal of Urology published a 7 year follow-up study of patients taking 5mg finasteride (5x dose of Propecia) and found no significant increase in Prostate cancer risk (Dr. G. Andriole was the lead author, Ref: J Urol. 2005 Dec;174(6):2098-2104)
That article was prompted by the New England Journal of Medicine article published in July 2003, which alluded to an agressive form of prostate cancer with finasteride use (which was not correct from the follow-up study).