I've been getting annual physicals since age 40, which have included a DRE. PSA testing began at age 50, and were always in the the low range. At age 57, my PSA "spiked", going from 0.6 to 2.5 in a year. A retest 3 months later was 2.5. A biopsy followed and the rest is history.
I've had no immediate family members (father, brothers) diagnosed with prostate cancer. My uncle got it in his 70s and had a prostatectomy. He's now 88.
I've mentioned this here before, but a number of prostate cancer experts
recommend a first PSA at age 40 for all men, regardless of family history. If it's low, retest at 45, then begin annual testing at 50.