Prostate Cancer Testing
Medical Establishment Opinion
In an immediately subsequent editorial by Dr. H. Ballentine Carter, M.D., in the same journal (p 2293), he states that what we really need to detect are the more agressive cancers, that develop quickly, and consequently cause more risk. However, these particular cancers have, in fact, a lower PSA level that the less agressive types. Second, the cancers with a low PSA level are small, and therefore pose less of a risk to the patient. Third, there is no evidence that the survival probability is any better when the cancer is detected this early. Fourth, other studies show that there is no significant increase in survivability, when the threshold is lowered below 4 ng/ml. Last, the overall lifetime probability of prostate cancer mortality is 3%; the lifetime probability of being diagnosed with prostate cancer at this level is 16% - so evidently we are already diagnosing many more people than actually can be saved by early treatment.
These conclusions should be modified, based on the subsequent publication in the New England Journal of Medicine (v 351, p125, 2004). This publication emphasizes that the speed (or rate) at which the PSA count increases, indicates how much risk is caused by the cancer. If one detects a rate of increase of 2 ng/milliliter per year, it points to a significantly more risky cancer compared to those whose growth rate is lower. We provide more details on the next page.