Antibiotics before biopsy reduces PSA but not PC

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reachout
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Date Joined May 2009
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   Posted 5/2/2011 6:09 AM (GMT -6)   
Antibiotics and/or alpha blocker agents may decrease the PSA levels before biopsy but not detection rate of prostate cancer

I found this interesting:

PSA levels remained above 2.5 ng/mL in 287 patients and 55 (19.2%) of them had CaP, which was found to be significantly higher in comparison to patients with post-treatment PSA levels below 2.5 ng/ml (p<0.05).

This mirrors my case. My PSA dropped from 4.1 to 2.6 after antibiotics, so I delayed my biopsy. The PSA eventually increased to over 5 a couple of years later with a positive biopsy. Had the antibiotics not been used, and my PSA not dropped, I may have had a biopsy and been treated much earlier, before my PC had gone to Gleason 4+3.

However, the paper also says that in those whose PSA dropped below 2.5, only a small percentage had cancer.

http://urotoday.com/article-base-category/eau-2011-antibiotics-andor-alpha-blocker-agents-may-decrease-the-psa-levels-before-biopsy-but-not-detection-rate-of-prostate-cancer-session-highlights.html

rob2
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   Posted 5/2/2011 8:32 AM (GMT -6)   
Interesting. I had a psa of 3.8 and took antibiotics and PSA went to 2. Three months later it was over 3.8 again and the rest is history ( along with my prostate).

Casey59
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Date Joined Sep 2009
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   Posted 5/2/2011 12:15 PM (GMT -6)   
One can have prostate cancer and prostate infection at the same time, as well as BPH, with all three independently contributing to increased measured PSA in the blood. Most men, however, with elevated PSA do NOT have prostate cancer, whic is why it is important to systematically eliminate the contributions of non-cancerous PSA.

reachout
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Date Joined May 2009
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   Posted 5/2/2011 2:06 PM (GMT -6)   
Casey, I agree. I think this is exactly what happened in my case, and what happens in many cases. The lesson here is not that antibiotics should not be taken, or that the PSA should not be measured, but that an infection might be taking place along with the cancer.

It also means, in my case, that I was one of those cases in which 2.6 was enough of a trigger that indicated fairly aggressive cancer. I drew the short stick, because usually 2.6 is too low to indicate any cancer and, if it does, it would be Gleason 6 at best. But within 2 years of that I was Gleason 4+3 (from pathology)
Age: 66
PSA: 7 tests over 2 years bounced around from 2.6 to 5.6
Biopsy 8 of 12 positive, Gleason 3+4, T2a
DaVinci August 2009, pathology Gleason 4+3, neg margins, T2c
Continent right away, ED
Viagra, Cialis did't work, Trimix works well
Post-surgery PSA:
3, month: undetectable <.1; 6 month: undetectable <.014 (ultrasensitive); 9, 12, 15 month: undetectable <.1; 18 month detectable .05

Casey59
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Date Joined Sep 2009
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   Posted 5/2/2011 10:12 PM (GMT -6)   
reachout said...
...because usually 2.6 is too low to indicate any cancer and, if it does, it would be Gleason 6 at best.
 
 
There is no such correlation to low PSA being "Gleason 6 at best." 
 
In fact, the more aggressive Gleason 8s and 9s tend to express very little PSA. 
 
On the other hand, the somewhat rare but very aggressive NED strain of PC grows a large tumor--often Gleason 6--which throws off too little PSA for it's size.  This is why PSA density is an important qualification criteria for AS patients...to successfully screen out the rare but aggressive low-Gleason PC.

reachout
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Date Joined May 2009
Total Posts : 725
   Posted 5/3/2011 8:18 AM (GMT -6)   
There is no such correlation to low PSA being "Gleason 6 at best. In fact, the more aggressive Gleason 8s and 9s tend to express very little PSA.

Casey, I don't want to argue, and you're right that I misspoke about PSA vs "Gleason 6 at best," but my point was, and is, that there is a correlation between PSA and Gleason score (among other variables). If there wasn't, the many nomograms we go to would be useless as far as Gleason grade. Here is a paper that talks about the correlation:

http://www.ncbi.nlm.nih.gov/pubmed/18341718

There was a positive correlation of high-grade Gleason score in the surgical specimens to higher preoperative PSA, more extensive tumors, positive margins and more advanced pathologic staging.

When my PSA dropped from 4.1 to 2.6 after antibiotics, I think I was justified in thinking that either I didn't have PC or, if I did, it would be fairly early in the process, not a 4+3. That's verified by the averages that we see in the nomograms.

What you correctly pointed out, and was the case with me, is that even with a low PSA one can still have aggressive cancer, and I agree that the more aggressive ones don't put out as much PSA. But fortunately those are the minority of the cases, though I don't have the reference at hand. For most guys with PC, the higher the PSA, the higher the Gleason. I was in the minority of cases that proves that the correlation is far from perfect.

142
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Date Joined Jan 2010
Total Posts : 6949
   Posted 5/3/2011 8:41 AM (GMT -6)   
Reachout,
 
It is often that Casey & I disagree, but here, I'm on board. When I see terms like "positive correlation" I cringe.
 
I had a 7.4 PSA and a Gleason 4+5 post-op. If we use all the "statistics", my PSA should have been much higher. My uro did a good job on convincing me that PSA is just one of the items in the tool box.
 
I tend to think a lot of the nomograms are useless, as they have certainly not matched up to my situation.

reachout
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Date Joined May 2009
Total Posts : 725
   Posted 5/3/2011 9:12 AM (GMT -6)   
142, I've been the poster child for nomograms giving me false hope, but I still see them as a good tool to guide us through this very complex maze. When we go to the horse track, or play poker, do we look at the odds table before laying a bet, or just place it blindly? And even if we study the odds table, does that mean we're going to win? No, but it increases our odds of winning.

In hindsight, I should have gotten a biopsy when my PSA went to 4.1 without worrying about antibiotics, but I didn't. In hindsight, I should have gotten a biopsy even when it dropped to 2.6 but I didn't. I went by the odds, and I was wrong. But I'm still going by the odds if and when my PSA rises, to do SRT. I don't know if it would work, but if the nomograms show a 50-50 chance, I'll do it. Same with HT. I think all of us here are gambling that what we're doing is the right thing but, as with any statistical events, we may come up short.

Casey59
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Date Joined Sep 2009
Total Posts : 3172
   Posted 5/3/2011 10:03 AM (GMT -6)   

reachout, we are mostly saying the same thing now…I mainly wanted to remark on your “Gleason 6 at best” comment, and I think we’ve cleared that up.  My motivation for commenting is largely to clarify for the benefit of others who might be reading this post in the future.

I think it is beneficial to emphasize for newcomers who may read this post that PSA and Gleason scores are different variables.  PSA is roughly correlated to the amount of cancer present; whereas, Gleason is an indicator of aggressiveness.  When independently input into the statistical models (nomograms), they (along with other inputs) help to predict patient risk/outcome.

In today’s era of widespread PSA screening, there are much lower levels of PC being detected than in the early days of the PSA-era, including many cases of insignificant and indolent PC, and so your point is also correct that many cases of both low PSA and low Gleason scores are found.

best wishes…



reachout
Veteran Member


Date Joined May 2009
Total Posts : 725
   Posted 5/3/2011 11:05 AM (GMT -6)   
No problem, Casey. Actually, that was a good catch. What I should have said is that with my PSA at 2.6 I erroneously thought that I would be at best a Gleason 6.
Age: 66
PSA: 7 tests over 2 years bounced around from 2.6 to 5.6
Biopsy 8 of 12 positive, Gleason 3+4, T2a
DaVinci August 2009, pathology Gleason 4+3, neg margins, T2c
Continent right away, ED
Viagra, Cialis did't work, Trimix works well
Post-surgery PSA:
3, month: undetectable <.1; 6 month: undetectable <.014 (ultrasensitive); 9, 12, 15 month: undetectable <.1; 18 month detectable .05

HD_Rider
Regular Member


Date Joined Apr 2011
Total Posts : 414
   Posted 5/3/2011 11:08 AM (GMT -6)   
When I had my original PSA done back in February, my PSA came back at 5.0. Before sending me to the urologist, my family doc put me on 750mg of Levaquin daily for 10 days. A subsequent PSA showed my PSA dropped to 4.5, which is really insignificant.

That's when I was then sent to the urologist who did a 12-core biopsy that later confirmed the presence of PCa.

I know a lot of the PSA level can be somewhat attributed to the size of the prostate gland, but the size of mine came back at 25cc, much too small to justify my elevated PSA readings.
John (HD_Rider) - Wichita, KS

Post Edited (HD_Rider) : 5/3/2011 11:11:40 AM (GMT-6)

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