Finasteride and Intermittent ADT

July 8, 2010

The following study reports that men taking finasteride (Proscar)

and engaging in intermittent ADT can get a much longer doubling

time than those who don't take finasteride.

I don't know how generalizable the results are since only six men

were studied, though it was over a period of 7-10 years. However

the results were pretty dramatic, extending the doubling time

from an average of 7.7 weeks to 45.1 weeks! Here's the

conclusion of the abstract:

Administration of finasteride was associated with a reduction

in the rate of increase of serum PSA in the off-treatment

period of any given cycle within a sequence of 5. In a total

of 15 cycles, finasteride extended PSA doubling time from a

mean of 7.7 weeks (n = 11, range 2.3-29.8 weeks) to a mean of

45.1 weeks (n = 6, range 13.8-99.7 weeks). One patient was

characterized by an apparent pseudo-resistance to finasteride

in the 2nd cycle of treatment and another patient by complete

resistance to finasteride in the 4th cycle.

Finasteride can be introduced into any cycle of intermittent

androgen suppression with the expectation of an extension of

PSA doubling time.

Finasteride is a form of hormone therapy, so it's not surprising

that it has an effect. But it is said to be one of the mildest

forms of HT with fewer side effects than more potent drugs like

Lupron or Casodex.

As always with studies like these, we don't know if this

translates to increased life extension, or just to lower PSA.

But it's something to consider for those of us on intermittent

ADT.

If you start an ADT off period with a PSA of 0.1, and decide to

get back when PSA >= 4.0, that's 5.32 doubling periods. Assuming

the average response (and of course it differs from one man to

another), the difference between 7.7 weeks per period

and 45.1 weeks per period is:

5.32 * 7.7 = 41 weeks = 0.8 years time off

5.32 * 45.1 = 240 weeks = 4.6 years time off

It looks like a big difference to me.

Alan

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