It’s been a week since my last PSA results came in—it seems like eons ago—and I really have been able to just ignore them for pretty much the entire time. That’s good.

With the yo-yo movement in my PSA over the last 4 tests, I can’t conclude much of anything aside from the fact that there will be more PSA testing in my future.

The engineer in me reflected on the last year of testing looking for some logical explanation.

I do remember that a year ago, just before the September test, I made the mistake of having an orgasm within 24 hours of the test. I thought that may have explained in the increase from undetectable to 0.05 ng/ml. But then the doctor threw in the possibility of the new ultra sensitive PSA test skewing the results. Two variables that weren’t present for the previous undetectable test.

For the December and April tests, I eliminated one variable by abstaining from orgasms for a nearly a week before the blood draw. The doctor asked me to abstain for two weeks for the August test, and I did.

If the next PSA test 3–4 months from now stays in the 0.05–0.08 range, I’ll be more inclined to think that this is a result in the change to the ultra sensitive test and nothing more. (Part of me wants to go to another lab for an independent test and see what it produces, but that will just introduce one more variable when we’re trying to eliminate them.)

At 0.05–0.08 ng/ml, I’m still well below the widely accepted biochemical recurrence threshold of 0.2 ng/ml. That generally makes me breathe a sigh of relief, and I think that I can come to terms with living with those numbers if that’s all it is.

But a UCLA study published in May 2015 showed that, under certain conditions, the ultra sensitive PSA threshold of 0.03 ng/ml was a good predictor of recurrence.  Yes, it was a small (247 patients) retrospective study, but that little fact has stuck in the back of my mind and gives me concern. (I wrote in more detail about it in my Day 1,768 post.)

There was also a Johns Hopkins study published in February 2016 that also indicated that low PSA levels measured by an ultra-sensitive PSA test were predictors of recurrence.

So I’m going to just wait until the doctor appointment on 23 August and see what she has to say about all this. It will be interesting—maybe even entertaining.