This chart compares prostate cancer tumor volume measured by MRI, at baseline and at 6 months, comparing placebo to Dutasteride. This was a randomized, double-blind, placebo-controlled clinical trial.
The cohort included Low and Intermediate Risk men, GS-6-7, baseline PSA = 6-7, median age 64 y.o, N=42.
The average tumor volume increased by 17% in the placebo group , while the average tumor volume decreased by -31% in the Dutasteride group, over the 6 month period. The difference between these two percentage changes is 48%.
Yes, DHT is made from T. So, if T goes down, so does DHT. What's neat about Dutasteride is that the DHT is reduced by 95% and the T and E increases by 20%.
There isn't a lot of data out there about Dutasteride and CRPC.
Here is a plot of PSA drop versus patient ID # after 6 months on Dutasteride. The green arrows indicate people who are non-responders (in my opinion). In the first group of men who don't have PCa, the % of non-responders is about 15%. In the second group, men with PCa, the % of non-responders goes up to about 30-35%, depending on how you count them.
Actually, for castrate-resistant men, I would not expect Dutasteride to have much of an effect on lowering PSA. By definition, being "castrate-resistant" means that lowering T (or DHT) to castrate levels won't have any effect on PCa.
There is a paper by S. Shah that looked at castrate-resistant men, and he concluded that Dutasteride didn't have much of an effect on lowering PSA, except in a few patients.
Dutasteride might be a useful adjunct drug to use with BAT therapy.
Do any of the studies your researching/graphing give any indication of how many people taking dutasteride get diagnosed with high-grade/aggressive cancers?
The short answer to your question is no study has shown an increased risk of high-grade PCa with Dutasteride, that I am aware of. (Perhaps someone can provide a study that contradicts this statement?)
You are referring to the black box warning label on Finasteride, which was applied to Dutasteride in the USA. The UK has no such warning for Dutasteride.
This old warning has since been debunked by many authors. If you send me an email to janebob99@lobo.net, I will send you papers that debunk this warning.
But, I did make a chart showing the raw data from the original paper by Thompson (2003) that was the basis for the black box warning on Finasteride. You can see that there was an increased rate of high-grade prostate cancers after 7 years of (6%) for Finasteride versus Placebo (5%) (N=4368). That's an absolute difference of 1% between Finasteride and Placebo. You can review the paper to see the actual numbers of men in this risk category.
Interestingly, Thompson et al. state that their conclusion about high-grade PCa incidence may have a bias error due to the significant shrinkage of the prostate with Finasteride, causing a "bias against any evidence of benefit for finasteride". Shrunken prostates will have a higher probability of detecting high-grade (large) tumors when doing random needle biopsies. That is called a "detection bias" in the literature.
Note: Thompson only studied Finasteride, not Dutasteride.
Many recent studies (with large numbers) have been published since 2003 about Dutasteride and PCa, and none of them show an increased risk of high-grade PCa. The average reduction in PCa risk when taking Dutasteride is reported to be 38% [23%-51%].
For an N=1, my own PSA dropped by 76%, from 10.0 to 2.44, after 4 months on Dutasteride monotherapy (no ADT). That makes sense, because Dutasteride reduces DHT by 95% (DHT is the primary form of testosterone that binds to Androgen Receptors on PCa cells).
MRI measurements of tumorvolume (Moore (2017)) have shown that pre-existing PCa tumors shrank in size by 30% when taking Dutasteride compared to Placebo (which grew 17% during the same time period), for a net difference of -48%shrinkage between Dutasteride and Placebo. This tumor shrinkage mostly explains why the PSA reduces by 50% (on average) when taking Dutasteride (note: the prostate gland itself shrinks by about 25%, which also reduces PSA).
Interesting findings! My acquaintance also took Dutasteride, and he noticed positive changes as well. However, of course, each case is individual, and it's important to consider all aspects of treatment when making a decision. Just as it's important to use only verified sources for ordering medications like Dutasteride and others, here's a pharmacy that is recommended by many people, you may try it too - global-world-delivery.com
It's good to see that there are studies confirming the effectiveness of the medication.
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PSA Ultrasensitive 0.015 six months after prostatectomy
Diagnosed 4+3
Active surveillance has ended after one year. RP now recommended.
