Actually the previous poster is right. Population based studies suggest that more harm than good is done by screening for prostate cancer.

The evidence goes like this. Once you have an elevated PSA, you see the urologist who orders a biopsy. Biopsies and treatments for prostate cancer carry risks like bleeding and infection, urinary incontinence and impotence. Now most prostate cancers will not kill you or cause problems in your lifetime. So investigations and treatments for prostate cancer cause more harm to people than the cancer does. This makes sense in a population, but not to the guy who got a bad cancer.

The current guidelines do not suggest PSA's in all men over fifty, but rather that you discuss the risks and benefits of screening, plus potential harm of further workup of a positive screen vs. the harm of developing prostate cancer. In practice, there is no patient who can actually understand enough of this to truly make an informed decision. Many docs haven't heard of the 'new' evidence and continue screening. The ones who do know of that evidence often ignore it because it's hard to explain, and patients will love you for finding an early cancer, even if it would never have affected them.

As far as your colon cancer screening comment, what you describe is standard of care.

The other thing to consider is that medicine in the US is HUGELY biased by the litiginousness of US culture. US emergency medicine guidelines, for example, are extremely aggressive and notorious for over investigating. The priority is protecting practitioners from litigation rather than appropriately treating the patient. A lot of those investigations are not recommended in socialized health care systems because they are not cost effective, nor do the benefits outweigh the disadvantages.

I practice evidence based medicine as much as possible. The trouble is that patients have a very hard time understanding it, let alone appreciating it.

I don't give antibiotics for colds, but those patients often go see other doctors to get their antibiotics. When they get their inappropriate prescription, ironically I come across as a bad doctor for not prescribing it in the first place.

When people bring their kids in to get some gravol for their viral gastroenteritis, I tell them that it has been shown to be no better than placebo, so I don't offer it. Parents hate that.

I have a cranky baby at home. My friends asked me why I don't use Oval. I told them that there is evidence that it doesn't work. They stared at me like I had three heads. After all, they tried it and it worked for them!

People come in with back pain. My job is to rule out the dangerous causes, and once that's done give them some analgesia and tell them to weight a few weeks for it to improve. Any serious pathology will reveal itself over time if there are no red flags during the initial history and physical. Patients hate that. They want the xray. So they go to their chiropractor who orders a bunch of xrays (placebo 'tests' are very therapeutic to patients actually). "Well, your xray looks fine!"

EBM is hard on the practitioners. The old school of medicine is to say, "This is what you have and this is what you need to do to fix it."

Now we say, "It's likely that you have this, although I can't say for certain. Here are the pros and cons of the treatments. Now what would you like to do?"
Very dissatisfying to a lot of patients.

Everyone wants all the scans and tests even when it doesn't make sense, because they all know the guy who was told that his problem wasn't serious and it turned out to be cancer etc.

The previous party line was that all diabetics should be on aspirin to decrease their chances of having a heart attack. A recent study came out showing very little evidence for primary prevention of heart attacks with aspirin. What to do now? How to integrate every little bit of often conflicting evidence into clinical practice? It's very hard to stay up to date, let alone sift the wheat from the chaffe.

EBM is the gold standard of how we should practice medicine. Yet it is immensely frustrating to put into actual practice.