Neither the rectal check nor the PSA blood test alone is sufficient. You really need to have both done yearly. I had an aggressively growing form that came in just barely over the cutoff. If I'd had the blood test a month or two earlier it'd been below the limit and I wouldn't have been told about it (this was during an examination for life insurance). As it was, by the time I got in for surgery the tumor had made it to the edges of the prostate gland. Had the test been done several months later the tumor would have been into the lymphatic system and changes for a successful recovery would have been low. After getting the bad news I went to the doctor. The rectal exam was negative, so by itself it is not conclusive.
So . . . every year get both a rectal and a PSA blood test. It's important to know what your baseline PSA level is. If it stays flat year to year that is good. If it starts climbing, even if it's below the cutoff of 4.0, then it's something you need to check into. ASAP! If you don't know your baseline number you won't know if it's climbing or not.
I hate doctors, but this is an easy one to beat if it's caught early enough. Get on it guys, you owe this to your wives, kids, parents,and all those around you.
Matt