Thoughts on accuracy of Psa and Ultra Psa tests?

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BobCape
Regular Member


Date Joined Jun 2010
Total Posts : 416
   Posted 12/6/2010 11:14 AM (GMT -6)   
Hi Folks. This is a roller coaster I wish none of us had to ride. But it is what it is.
 
My intial 3 mo post RP PSA was <0.1 - lowest that lab goes.
My 6+- Mo PSA, new lab, ultra sen PSA was 0.13.
One week later my uro (@Boston Med Center) gave me one, 0.20
Today, 2+- weeks after that, same lab that did the ultra 6 mo @ 0.13, comes back with 0.14.
 
SO, I guess I should be glad I dont have to look at that .20 as being gospel?
 
Nov 9th the ultra said 0.13.
Dec 1 the ultra came back at 0.14.
 
How would YOU interpet these results?
 
Thanks so mych in advance, my thoughts and prayers go out to each of you!
 
Bob - Cape Cod (should be Cape Cold today :)).

Purgatory
Elite Member


Date Joined Oct 2008
Total Posts : 25394
   Posted 12/6/2010 11:48 AM (GMT -6)   
Bob,

This is why I have had all my PSA tests done by the same lab since 2002, I like consistency in the results.

But as far as your numbers go, I would interpet that if you get one more PSA done in a month or more from now, and its
above the lastest .14, most would feel that you have post surgery reccurance.

If you haven't already, I would be lining up a good radiation oncologist or even medical oncologist to start getting some secondary
treatment advice in advance.

Hoping you aren't having to go down that path.

David in SC
Age: 58, 56 dx, PSA: 7/07 5.8, 10/08 16.3
3rd Biopsy: 9/08 7 of 7 Positive, 40-90%, Gleason 4+3
open RP: 11/08, on catheters for 101 days
Path Rpt: Gleason 3+4, pT2c, 42g, 20% cancer, 1 pos marg
Incont & ED: None
Post Surgery PSA: 2/09 .05,5/09 .1, 6/09 .11. 8/09 .16
Post SRT PSA: 1/10 .12, 4/8 .04, 8/6 .06 11/10 Not taking it
Latest: 6 Corr Surgeries to Bladder Neck, SP Catheter since 10/1/9, SRT 39 Sess/72 gy ended 11/09, 21 Catheters, Ileal Conduit Surgery 9/23/10

BobCape
Regular Member


Date Joined Jun 2010
Total Posts : 416
   Posted 12/6/2010 12:18 PM (GMT -6)   
Already scheduled to start Radiation on 12/23.

Tim G
Veteran Member


Date Joined Jul 2006
Total Posts : 2366
   Posted 12/6/2010 12:23 PM (GMT -6)   
Bob,
 
It appears that while your results vary, they have consistently been above 0.1 ng/mL.  You may want to discuss follow-up testing and options with your urologist.  I agree with David, that, if possible, it's best to use the same lab. Be aware that there is test-to-test and day-to-day variation using the same testing instrument.  For example, the same blood sample may yield a result of .014, 0.13, and 0.16 when tested three different times on the same instrument.  I have used the same lab for PSA testing for over 15 years, but they switched to a new ultra-sensitive instrument for all PSA testing and my latest result was reported differently.  Personally, I prefer the standard testing to the nearest tenth nanogram (0.1).  A nanogram is a billionth of a gram, so the testing will still pick up infintessimally small changes in PSA.
 
All the best on your continued recovery!
 
Tim

Carlos
Regular Member


Date Joined Nov 2009
Total Posts : 486
   Posted 12/6/2010 12:33 PM (GMT -6)   
Bob,  It looks like you and I are on the same track.  My PSA numbers are similar to yours.  My radiologist recommends I start soon because of a high tumor volume with predominately Gleason grade 5 cells, significant perineural invasion and both nerve bundles spared.  With limited PSA results the risk is overtreatment, but delay could also be risky because of the GG 5 cells. We decided to start on the 15th.  Good luck with your coming treatment.
 
Carlos

Diagnosed 2/2008 at age 71, PSA 9.1, G8 (5+3), stage T1c.
Robotic surgery 5/2008, LFPF at 6 wks.,nerves spared, stg. pT2c, N0, MX, R0, G8 (5+3)
PSA .12 at 2.5 years, rechk 2 wks later 0.2. All prior tests <0.1.
Start SRT 12/15/2010

BobCape
Regular Member


Date Joined Jun 2010
Total Posts : 416
   Posted 12/6/2010 12:38 PM (GMT -6)   
Thank you both.

My concern with the standard testing is best identified by the two among these results.

The 1st, at Cape Cod Hospital <.010 (simply less than .1).
The 2nd, at Boston Medical Center 0.20.

Then the end ultra, brings me a 0.14 - making me feel a bit better than .2.

But really, CCT considered .1 as undetectable. And .2 is when you should consider radiation.
So using the standard test, you really have an on/off switch, it's either undetectable, or you need radiation.

Purgatory
Elite Member


Date Joined Oct 2008
Total Posts : 25394
   Posted 12/6/2010 12:39 PM (GMT -6)   
Bob,

That's good to know. Your post surgery numbers are tracking like mine were, and there was a lot of concern with my pre-treatment
PSA velocity issues, so there was a push to start Salvage Radiation, which was a big issue for me.

My feeling, is that the .x testing is fine when there's no danger of recurrance or if one's numbers are very stable. But if you have positive margins or other issues going, or just a bad pathology in general, I feel strongly that you need .xx readings to watch for early rises if they take place, and to see if there is a rising trend taking place before it becomes problematic.

David
Age: 58, 56 dx, PSA: 7/07 5.8, 10/08 16.3
3rd Biopsy: 9/08 7 of 7 Positive, 40-90%, Gleason 4+3
open RP: 11/08, on catheters for 101 days
Path Rpt: Gleason 3+4, pT2c, 42g, 20% cancer, 1 pos marg
Incont & ED: None
Post Surgery PSA: 2/09 .05,5/09 .1, 6/09 .11. 8/09 .16
Post SRT PSA: 1/10 .12, 4/8 .04, 8/6 .06 11/10 Not taking it
Latest: 6 Corr Surgeries to Bladder Neck, SP Catheter since 10/1/9, SRT 39 Sess/72 gy ended 11/09, 21 Catheters, Ileal Conduit Surgery 9/23/10

BillyMac
Veteran Member


Date Joined Feb 2008
Total Posts : 1858
   Posted 12/6/2010 3:43 PM (GMT -6)   
Bob,
I would think that not many labs would use equipment or assay that delivers a result to only one decimal point. That is pretty old technology today. However many do round the result to one decimal point (often the way many uros want it reported). What this basically means is, if your result is 0.14 or lower it will be reported as 0.1 --------- if it is 0.15 or slightly above it will be reported as 0.2. Reporting it one way it shows it has barely changed while reporting it the other, it would appear on paper to have doubled. I feel it is important to consistently use the same lab --------- this at least will remove the variation that can and does exist between the different labs' calibration. Even with your ultrasensitive result this could also be deceptive. Many labs actually obtain a three decimal result and round up to two. In such a case 0.014 would be reported as 0.01 while if the actual result was 0.015 this would be reported as 0.02
Bill

Post Edited (BillyMac) : 12/6/2010 1:51:19 PM (GMT-7)


LV-TX
Veteran Member


Date Joined Jul 2008
Total Posts : 966
   Posted 12/6/2010 4:47 PM (GMT -6)   
BillyMac,

I was told that the assays will not round up or down like you are showing. If the lower detection limits are 0.1 then anything between 0.1 and 0.19 are going to show 0.1 only. Until the level is at or above the 0.2 level it won't be shown as 0.2. Logically we like to think this way, but machine assay testing won't round up or down. One of the reasons for going to the 0.XX range, because a 0.19 offers a lot more information to the doctor than a simple 0.1 One of the methods of determining early if there is a recurrence, is three consective rises above the 0.1 mark. A person could have three consective rises between 0.1 and less than 0.2, but the assay would only show 0.1 if the standard assay is used.
You are beating back cancer, so hold your head up with dignity

Les

Signature details in Sticky Post above - page 2

goodlife
Veteran Member


Date Joined May 2009
Total Posts : 2692
   Posted 12/6/2010 8:13 PM (GMT -6)   
Bob,

I am doubtful that labs would round down for results, but I am not a lab expert. I would rather think they would post it as less than the next highest point, as in <.1 or <.2.

I am an advocate of ultrasensitive as an aid in following PSA progression. I am a little suspicious of the .2, as not being of the same assay type. Worried Guy has posted some interesting threads on the wide differences in PSA testing techniques.

The bad news, which apparently is not new news to you, is that you will require step 2. I wish you well during your SRT, and will watch for progress reports.

May you find the little suckers sleeping in the bed.
Goodlife
 
Age 58, PSA 4.47 Biopsy - 2/12 cores , Gleason 4 + 5 = 9
Da Vinci, Cleveland Clinic  4/14/09   Nerves spared, but carved up a little.
0/23 lymph nodes involved  pT3a NO MX
Catheter and 2 stints in ureters for 2 weeks .
Neg Margins, bladder neck negative
Living the Good Life, cancer free  6 week PSA  <.03
3 month PSA <.01 (different lab)
5 month PSA <.03 (undetectable)
6 Month PSA <.01
1 pad a day, no progress on ED.  Trimix injection
No pads, 1/1/10,  9 month PSA < .01
1 year psa (364 days) .01
15 month PSA <.01

livinadream
Veteran Member


Date Joined Apr 2008
Total Posts : 1382
   Posted 12/6/2010 8:27 PM (GMT -6)   
Thanks for posting and this is an interesting question that in my three years has seen its fair share of controversy.
I have not read the replies and I am sure most will not agree with my thoughts. As a gleason 9 stage 4 prostate cancer patient I probably take psa less serious than most. I have seen folks get excited when it goes from .02 to .07 when reality is in my eyes it is still zero. I think PSA should be monitored and trended but I do not think we should overreact to slight rises that are still low. Ok just my silly opinion. I think I will go out for a 5 mile run. That hard core exercise seems to keep my cancer in check. ok another point of controversy I am sure. boy I am on a role tonight.

peace and love to all
Dale
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