Bluntly, no they absolutely aren’t!
One of the most infuriating problems is that for many men a diagnosis of prostate cancer is not clinically significant at all! If you look at the prostates taken from 100 American men over 50 years old who die in car crashes and similar accidents, i.e., men who never showed any clinical sign of prostate cancer while they were alive, you can, in fact, find small areas of cancer in the prostates of about 30 of those men (30 percent). Those men could have lived for years with those small areas (foci) of prostate cancer — or some of them could have been diagnosed with clinically significant prostate cancer just a few months later if they had lived. If you do the same thing with American men over 90 years old, you find that 90 percent of them have microscopic evidence of prostate cancer.
These small areas of prostate cancer tissue that do not develop into clinically important disease have historically been called “indolent” or “latent” prostate cancer. For an average American man of 50 years of age, with a reasonable life expectancy of another 25 years, the chance that he will develop a microscopic focus of so-called “latent” prostate cancer tissue is estimated to be 42 percent (i.e., 42 of 100 such men will get such a microscopic focus). However, the chance that the same man will get clinically significant prostate cancer (i.e., prostate cancer that is associated with clear signs or symptoms of the disease) is only 9.5 percent. Finally, of the same 100 men, in 2008, only about two were actually expected to die of prostate cancer. So you can clearly see that while many men may get diagnosed with prostate cancer, it will actually affect relatively few of them very seriously in the long term. It is often said that most men are much more likely to die with prostate cancer than because of this disease.
The problem, of course, is that we do not yet know how to tell which men with a small focus of prostate cancer are most likely to go on to get clinically significant disease. This is one of the most important things to understand about prostate cancer. It affects almost everything about the disease. It is something you should think about and discuss with your doctor before you ask to have specific tests for prostate cancer, and most certainly before you receive treatment for early stages of prostate cancer which are confined to the prostate.
Depending on your age, health, family history, race, and a bunch of other stuff, you may be better off not having the specific tests if you have absolutely no reason to believe you are at risk for prostate cancer. And even if you are diagnosed with a small focus of cancer confined to the prostate, you may be better off if the doctor practices some form of “expectant management” process (e.g., active surveillance or watchful waiting) rather than attempting curative therapy. You and your doctor need to make decisions like this together, and you should ask your doctor for all the information he or she can give you before you take those decisions.