Gary (or is it Irwin?),

Why would you want biopsies every six months?  If you're thinking Watchful
Waiting, you need to keep in mind that your PSA went from 2.5 to 5.7 in six
months.  Right now, T1c puts you right smack dab into a probability of cure.
You're at 80% for no capsular penetration right now.  If your PSA goes up
past six (which is very likely), you'll be at 75%.  If you wait until it's
palpable, it drops to 58% or 49%, depending if you have it in one lobe or
two.

Rather than repeated biopsies, you should be considering, IMHO, whether
you're in good enough shape for surgery or if you prefer the idea of
radiation but not knowing.

You should ask your doctor that question.  I haven't seen any studies
which investiage whether repeated biopsies at 6 month intervals have
significant side effects, beyond the obvious immediate potential effects
such as infection, but that doesn't mean there aren't any.

If your doctors haven't recommended immediate treatment by surgery or
radiation, it is because they may consider you a candidate for watchful
waiting.  Some men in their late 60s with Gleason 6 tumors and other
promising signs such as small tumor volume and low PSA are considered to
be in that category.  They are then followed carefully, and that would
include more frequent PSA testing as well as repeated biopsies to be
sure the cancer is not progressing.   In thinking about this, it is
important to balance any possible risk from repeated biopsies against
the risk of missing a sudden change in the nature of the tumor.

I am surprised that with a such a large PSA increase in 6 months that
you would be considered a candidate for WW.  But it may be that your
doctors think that had a cause different from your prostate cancer.  If
I were you, I would certainly try to get a full explanation for the
choice of treatment.