I was in similar circumstances to you similar age, no obvious symptoms My brother had PC and I requested a PSA test for peace of mind. The start figure was 6.4, told not to worry etc. Tested every six months for the next four years and it crept up each time Even at a reading of 9.8 I was told not to be concerned, 'slow rate of increase' keep monitoring.
The next test was 10.4 and the GP's responses were going along the same lines and I asked for further tests. Urology Consultant, following by biopsy, All samples were positive for cancer and prostate removed within 6 weeks. (in June this year) As far as I know it hasn't escaped elsewhere but in retrospect I feel that it was left far too long, I was too complacent to go along with what the Doc said without doing my own research and finally, that I will be lucky if it was caught just in time.
I would say insist in further checks to give you some certainty and hopefully the chance (if cancer is found) to have some of the lesser treatments before it gets to the high impact stuff.