"PSA is unreliable, even in people with diagnosed and treated PCA.
it should never be used for its 'absolute' value, but changes - especially trends, as one test could be misleading - can serve as a warning, and extreme changes are certainly a big red flag. It isn't a tracker, in that two people with a similar tumour could have wildly different PSA. Two people, one of whom has metastatic spread, one doesn't, could have the same PSA."
........I guess I'm not explaining myself clearly enough. I'm asking a specific question relating to my circumstances, which I thought I'd given. I'm not talking about two people. I'm not trying to prove that I am indisputably correct in the term 'tracker' . We can debate the meaning of 'tracker' -a crude and fallible indicator, if you like. Are we not monitored regularly for trends in PSA ( allowances made for blips etc)? You say something akin to this:
"But done regularly, a rising trend certainly suggests a need for further investigation, but that's all."
"There's a real danger in letting yourself think it's like haemaglobin, blood sugar, whatever - a lifetime of avoidable anxiety!"
........PSA is PSA, I'm not letting myself think it is anything other than PSA. Production of antigens varies. PSA is not in direct relation to the growth/presence of cancer, but it is used as PART of the diagnostic picture, and post -operatively ( recall, that is my situation) it is all that is ROUTINELY monitored. We can argue the value of that monitoring, but again, that is not what I am asking. I think we can agree that things 'upset' the PSA readings in THIS scenario. A blip can be argued to be the result of something outside of prostate cancer dynamics. But Oestrogen administration would not be a blip, it would likely be for life.
.......I have already tried to explain, offering a scenario where regular use of oestrogen knocks back the PSA levels to the point where cancer may develop without a tracker ( or crude fallible suggester of something awry, if you prefer) to make it known. Of course, we can say that PSA will not indicate cancer development ( in THIS scenario) for definite. But in the absence of better prognostics, I'd like to exploit the partial knowledge that regular monitoring might provide. It may well be that, with oestrogen, all bets are off, and PSA monitoring is entirely useless. After all, this would be oestrogen not released at a steady state into the body, and itself only monitored to the point where a satisfactory level in blood is achieved at the time it is monitored.
"I would certainly argue for regular PSA tests for people with cancer. But I'd strongly advise against ever assuming it's reliable. Because it isn't."
"Sadly, being 'body-aware' and acting fast on anything odd, painful or unexpected is probably more important. I'd hate to hear anyone say "I've got this nagging pain, but my PSA is OK"