A good urologist is the place to begin. In my situation I sought a urologic surgeon at a urology department of a major medical school. His colleagues in the same clinic are experts who practice in various sub specialties of urology. This might be the best place to begin. Find a doctor whose colleagues practice in sub specialties; therefore, if your doctor does not know the answer perhaps he can call upon his colleagues.
My personal opinion which is not a medical opinion, is to get a PSA test. Also, there might be other diseases and cancers that need to be ruled out. As an interesting footnote when I had radical prostatectomy my low back and hip pain ceased.
Bottom line, seek medical intervention from a qualified experienced group of urologists who are willing to undertake diagnostic testing.