Fluctuations in PSA

[easeytiger]

Interested in experience with monthly PSA numbers. I was diagnosed with PSA 55, following month 64, then 68, dropping to 45 and just had a test at 49. My specialist wants a retest in a few days then if this is confirmed scans to see what is going on. My specialist mentioned it could be a blip, but how likely is this? Thoughts appreciated.

[Tall_Allen]

With monthly tests, I think you are looking at it too closely, and creating needless anxiety for yourself. PSA output from metastases does fluctuate. Unless you are watching it to gauge the effectiveness of some therapy (like chemo), I would think that every 3 months is better to see long term trends. The decision to have any diagnostic test (like PSA) should be based on whether it can have a potential effect on treatment decisions. If there's nothing different you would do depending on which way the test goes, don't take the test.

[vandy69]

Good Saturday Morning easeytiger,

For the 4 1/2 years I was under the care of Dr. Charles "Snuffy" Myers, he ordered monthly blood tests from LabCorp to include ultrasensitive PSA tests.

That was his protocol and he was the recognized expert.

Best wishes. Never Give In.

Mark, Atlanta

[FCoffey]

Many things can make PSA fluctuate. It is affected by inflammation, not just cancer.

Continual fluctuations in PSA are sometimes signs of prostatitis. Some urologists will prescribe a round of antibiotics in an attempt to clear up any infection. Prostatitis is notoriously difficult to treat.

Ejaculation will raise PSA for a few days; try abstaining from sex for 48-72 hours before the next test.

Digital rectal exams will certainly raise PSA for a week or more. A biopsy will raise PSA for 6 weeks while the assaulted gland heals.

Many men get some inflammation of the prostate from drinking alcohol. Limiting alcohol is a good idea for any cancer patient; try abstaining for a few days before the next test.

I've been monitoring PSA monthly for a long time. It most certainly changes faster than that; I've seen it fall 25% in less than 2 weeks. Unfortunately, my PSA is much more often increasing rather than decreasing.

The advice not to perform any test unless it will influence treatment decisions is sound.

Good luck!

[easeytiger]

Thanks for all replies. I believe I will have monthly PSA tests until the numbers drop. I’m three months into Zytiga, so not sure whether this means it’s not working for me. I don’t drink alcohol or have sex (at the moment), no exams or biopsy since December.

[dave2]

Easeytiger, because the inherent result fluctuations from frequent PSA tests can be challenging to interpret, I see a couple of options: (1) only do the test every 3-6 months, or (2) test monthly, but focus your attention on a rolling average of the last two or three tests.

The advantages of option 1 are its simplicity, time saving, cost saving, and possibly reduced anxiety (depends on personality). The advantages of option 2 are earlier awareness if a substantial change occurs, more accurate tracking of "true" PSA level & trend (because of the smoothing effect of a rolling average), and possibly reduced anxiety (again depends on personality).

Option 2 is similar to how many technical analysts look at the stock market. Watching the daily fluctuations in a stock market index is not as helpful to understanding trend as looking at the pattern from a 50-day, and sometimes 200-day running average.

I have an analytical background, so I routinely chart monthly PSA, plus 3-month and 6-month PSA doubling times. The PSA doubling time figures are more accurate if you test PSA every month. And I find it reassuring to know where things stand with a monthly update of this metric. But my approach is not a good fit for most people, who will be better served with option 1. Obviously, if your PSA is changing a lot between tests or you are changing your treatment significantly, it makes sense to consider increasing the testing frequency.