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PSA doubling time calculator differences

Posted by aldenrobert @aldenrobert, 5 days ago

I just got my recent PSA results today. 12/22/2025 PSA 1.29 on 11/03/2025 PSA was 0.35.
I entered that information on the Sloan Kettering PSA doubling time calculator. The result was a doubling time of 0.9 months.
I entered the exact same information on he Omni PSA calculator and it said the doubling time was 0.56 months.
I am wondering why the were not the same? Is there a "best" calculator to use?
It really may not be relevant because they both indicate a very rapid doubling time. I have been on a treatment holiday for about 7 months. In that time my PSA has gone from 0.01 (04/25/2025) to 1.29. So my treatment holiday will be ending soon...

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jeff Marchi | @jeffmarc | 4 days ago
In reply to @harry100 "@aldenrobert Hello Alden, Mine went from a PSA 9 in Apr to PSA 7.42 in Dec..." + (show)
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@aldenrobert
Hello Alden,
Mine went from a PSA 9 in Apr to PSA 7.42 in Dec
They were the same in slope -0.3, but differed slightly in velocity -2.2 vs -2.34

I don't understand all this

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@harry100
What type of treatment did you have? If you had radiation the PSA drops over time.

Do you have a large prostate and have been on antibiotics?

Do you have BPH?

All of these can cause the PSA to rise and/or fall.

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1 reply
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harry100 | @harry100 | 4 days ago
In reply to @jeffmarc "@harry100 What type of treatment did you have? If you had radiation the PSA drops over..." + (show)
Profile picture for jeff Marchi @jeffmarc

@harry100
What type of treatment did you have? If you had radiation the PSA drops over time.

Do you have a large prostate and have been on antibiotics?

Do you have BPH?

All of these can cause the PSA to rise and/or fall.

Jump to this post

@jeffmarc

Hello Jeff,
I haven't been diagnosed yet. So I haven't started any treatment. I get my biopsy results on the 29th.
I have an enlarged prostate so I was prescribed a medication for it. Can't recall the name. It starts with a "T".
I apologize for not being more detailed.

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jeff Marchi | @jeffmarc | 4 days ago
In reply to @harry100 "@jeffmarc Hello Jeff, I haven't been diagnosed yet. So I haven't started any treatment. I get..." + (show)
Profile picture for harry100 @harry100

@jeffmarc

Hello Jeff,
I haven't been diagnosed yet. So I haven't started any treatment. I get my biopsy results on the 29th.
I have an enlarged prostate so I was prescribed a medication for it. Can't recall the name. It starts with a "T".
I apologize for not being more detailed.

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@harry100

The drug you’re referring to is probably Tamsulosin, though there is a faint chance that it could be Tadalafil (Cialis) which can also be used to treat BPH.

You could’ve figured it out by doing this search

“what medicine starting with a T would be given for an enlarged prostate”

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1 reply
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harry100 | @harry100 | 4 days ago
In reply to @jeffmarc "@harry100 The drug you’re referring to is probably Tamsulosin, though there is a faint chance that..." + (show)
Profile picture for jeff Marchi @jeffmarc

@harry100

The drug you’re referring to is probably Tamsulosin, though there is a faint chance that it could be Tadalafil (Cialis) which can also be used to treat BPH.

You could’ve figured it out by doing this search

“what medicine starting with a T would be given for an enlarged prostate”

Jump to this post

@jeffmarc

Jeff,
You are correct. It is Tamsulosin.

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heavyphil | @heavyphil | 4 days ago

0.56 sounds about right: PSA went up by a factor of almost 4X In just about 7 weeks - or almost 2 months…so it basically doubled in just over 2 weeks time…that’s pretty fast.
Don’t know why Sloan has you at 0.9 - all numbers entered correctly?
Phil

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aldenrobert | @aldenrobert | 4 days ago
In reply to @heavyphil "0.56 sounds about right: PSA went up by a factor of almost 4X In just about..." + (show)
Profile picture for heavyphil @heavyphil

0.56 sounds about right: PSA went up by a factor of almost 4X In just about 7 weeks - or almost 2 months…so it basically doubled in just over 2 weeks time…that’s pretty fast.
Don’t know why Sloan has you at 0.9 - all numbers entered correctly?
Phil

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@heavyphil
Yes. I entered the numbers and dates correctly. I think I did it at least three time and the results were all the same.

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