Does taking Tamsulosin plus Dutaseride for BPH mask true PSA numbers ?

[Simpson80]

Before I got diagnosed with PCa , I was taking Tamsulosin plus Dutaseride for many years to control symptoms of BPH.

My question is does taking them for many years show a false lower psa number than it actually would be ?

[Tall_Allen]

Dutasteride (not tamsulosin) cuts PSA by about half in men with BPH. This effect makes PSA a better indicator. If PSA doesn't reduce by half, or if it does, and PSA rises while still taking it, it is more probably due to prostate cancer than BPH.

[Simpson80 in reply to Tall_Allen]

Thank you. So when I was diagnosed with PCa the PSA was 21. Since I was taking dutaseride before that , does it mean the real number should read around 42 appx ? Or I am getting this wrong.

[Tall_Allen in reply to Simpson80]

Yes, that's correct if you were taking dutasteride for BPH.

[EdBar]

I’ve been taking dutasteride since dx per Snuffy Myers, not for BPH, my prostate was radiated, but to prevent the conversion of DHT, a potent form of testosterone. It is part of the triple therapy I’ve taken for 10 years now, prescribed by Snuffy Lupron/Xtandi/Dutasteride. Just sharing my experience.

Ed

[Simpson80 in reply to EdBar]

I am continuing it too. What dose do you take ?

[EdBar in reply to Simpson80]

0.5 mg daily

[fast_eddie in reply to EdBar]

I've been taking dutasteride for about four months now. I see myself being on this until something changes dramatically.

[Explorer08]

A cautionary note about Tamsulosin. I took it for a few years for bladder spasms but it eventually resulted in bradycardia. Doc switched me to Myrbetriq.

[janebob99]

Tall_Allen is correct on one point, but not the other about doubling the PSA.

Being on Dutasteride makes any future rise in PSA a better indicator of increasing prostate cancer, compared to a future PSA rise without Dutasteride. Many papers show this.

A PSA doubling time is still the best indicator of a growing tumor. Any doubling time less than 8-9 months is a red flag that a biopsy and/or a MRI should be done, and/or start additional treatment.

I've also been taking Dutasteride (and tamsulosin recently). My PSA dropped about 75% (from 10 to 2.4) after 5 months on Dutasteride alone (no other drugs). My prostate volume also shrank about 40%. That's my own experience, of course.

Only about 70% of men with PCa will respond to Dutasteride treatment, however. 30% are non-responders. No one has explained why this is.

Recent research shows that Dutasteride also reduces the size of a PCa tumor by about 30 % after 6 months (compared to a 17% increase in tumor size for Placebo), as measured by MRI. The reduction in tumor size is what causes the PSA to drop by about 50%, on average.

Dutasteride does not cause a "masking" effect, which some people often talk about. If you send me a private message, I can explain the origin of why people originally suggested doubling the PSA when taking Finesteride (precursor to Dutasteride).

Bob in New Mexico

[Conlig1940 in reply to janebob99]

Bob,

I am on Dutasteride for 5 years . I have also read where this drug can contribure to causing cancer .

[janebob99 in reply to Conlig1940]

Thank you for your comment.

I am well aware of the black box warning label on Finesteride (and, then Dutasteride). This was based on a single study in 2003 that found a 1% increase in the rate of high-grade cancers (6 % vs 5% for placebo). This lead to the black box warning (which they don't have in Europe, BTW).

Multiple papers since then have debunked this warning as being the result of a detection bias, and not a real effect. Basically, since Dutasteride shrinks the prostate significantly (40-50%), the probability of a needle biopsy hitting an existing (high-grade) tumor increases as the prostate volume decreases. So, more cancers are detected when taking Dutasteride. Dutasteride does not cause more cancer.

In fact, more recent studies (three large studies of N > 4000 men for each study) show that Dutasteride reduces the rate of prostate cancers by 20%-50%, depending on the particular study.

If you send me an email request to [e-mail], I'd be happy to send you .pdf's of papers that debunk this outdated belief from 20 years ago.

Bob in New Mexico

[Conlig1940 in reply to janebob99]

Thanks Bob,

I agree with this information .