To emphasise what Barry said, for goodness sake don't risk not being correctly diagnosed because of fear of the tests. In my own case, having those tests literally saved my life, because purely by chance the scans they did for prostate cancer showed up the far more serious but completely asymptomatic kidney tumour. My consultant told me that if that tumour (which was removed last Saturday) hadn't been found, I would assuredly have been dead from it within 4 years. So prostate cancer tests saved my life, no doubt about it. And that's the thing: until you have them, you never know what those tests will find!
All the best,
Chris