PSA
in [Prostate Cancer]
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From: Leonard Evens on 13 Feb 2005 17:26 Gut-Buster wrote: > "Leonard Evens" <len(a)math.northwestern.edu> wrote in message > news:4fydnSdGLtxtwJLfRVn-rA(a)comcast.com... > >>Gut-Buster wrote: > > > Thanks for that info. The stuff I had read said that PSAs did a hell of a > lot of false positives and not a small amount of negative results when there > should have been positives. There are a substantial number of false positives. But what that means is that you have a biopsy and the biopsy is negative. The biopsy procedure is quite safe and not particularly painful for most men. It would be better of course if they could reduce the number of false positives, but it is not a disaster to have a biopsy and find it comes out negative. It is also possible for the PSA to be normal and the patient to have prostate cancer. But there isn't much we can do at present about that. It is the reason why you should also have a digital rectal exam. The two of them together will catch the overwhelmingly majority of prostate cancers. > > >>Not all men with prostate cancer will have an elevated PSA. So urologists >>recommend both PSA testing and digital rectal examination--the "finger". >>Each would catch prostate cancers which the other will miss, but in the >>great majority of cases, the PSA test will find it earlier. >> > > > I find it more than logical that a cancer on the opposite side of the > prostate to where the finger feels would not be found by a finger probe and > that worries me a bit. Like most people I hate the finger test but put up > with it until I was treated like a hypochondriac for going for them, at > which point I stopped going. I had 3 tests in 3 years. Two tests were within > 6 months but were not my idea and totally unavoidable as I was bleeding and > there was really some worry about what was causing that (nothing to do with > prostate or cancer as it turned out and healed of it's own accord thank > goodness). When you get told by a doctor that "maybe it is about time for > you to grow up" you tend not to go back to a doctor. Strange thing is that > he was the same guy who told me I was especially at risk for prostate cancer > due to my chronic bacterial prostatitis. I am not a physician myself, but I've never seen it stated that prostatitis increased the risk of prostate cancer. You should find another doctor and ask his opinion. Don't just take my word for it. > In any case, this was the same > doctor who ended up in hospital with prostate and bowel cancer himself. > > >>If you are at special risk for prostate cancer, then it would be wise to >>have regular PSA tests in addition to digital rectal examinations (but > > > Never had a PSA test in my life but from what you have posted, I would > assume my PSA results would be unusually high anyway with my condition or > likely not found as I take a large dose of Saw Palmetto to help with the > problem and that is apparently able to mask PSA if I have that right. You shouldn't be trying to get medical advice over the internet. Find a doctor you trust, make sure you get him to explain it all to you, and then make sure you get regular exams. > >>However, all this is generality, and you are one man. You would be best >>advised to find a physician you trust and discuss the whole matter with >>him/her. The physician can take your particular situation into account >>and advise you about the risks and benefits for you either way. > > > I am not totally sure I could find a doctor I trust any longer. Having been > told to grow up by one, you tend to get a bad opinion of the whole lot of > them. There are plenty of good doctors out there. You shouldn't let your experience with one doctor put you off the whole profession. > > >
From: George Conklin on 13 Feb 2005 18:11 "Leonard Evens" <len(a)math.northwestern.edu> wrote in message news:WJ-dnRT6-4emUJLfRVn-3A(a)comcast.com... > George Conklin wrote: > > "Leonard Evens" <len(a)math.northwestern.edu> wrote in message > > news:4fydnSdGLtxtwJLfRVn-rA(a)comcast.com... > > > > > >>One reason you may be confused about this is that news media recently > >>publicized a study by one physician with a background in prostate cancer > >>claiming something along these lines. He recommended not testing for > >>PSA and waiting until something showed up on digital rectal examination. > >> This is decidedly a minority opinion which few other experts agree > >>with. Indeed, urologists have noted that after the advent of routine > >>PSA testing, the percentage of more aggressive relatively advanced > >>prostate cancers has decreased greatly. Implicit in this man's > >>conclusion is the belief that the great majority of the cancers > >>discovered by PSA testing don't need to be treated at all, so there is > >>nothing to lose by waiting for something to be felt. But the success > >>rate at curing prostate cancer is definitely lower > > > > > > Unproven statement Len and you know it. The science has never been > > done,. as you well know. > > > > > > Actually your argument also applies to diagnosing prostate cancer by > digital rectal examination. No double blind or otherwise suitably > randomized study has ever been done to show that life span is > increased---your criterion---by doing such examinations. Indeed there > are those who would argue not only against PSA testing but also against > regular DREs. They would leave all prostate cancer to be discovered > through symptoms of advanced prostate cancer. > And as I have said, women are 20 years ahead of men because they insisted on studies. We are now what, about 10 years into the studies for men, and no results yet announced. Why? Because so far it is not what tradition wants to hear. As you say, maybe 15 years out something may emerge. Don't know, but you don't either.
From: c palmer on 15 Feb 2005 05:42 From: D-D-D-DONT.stare(a)me.privates (Gut-Buster) Anyone got any comments on PSA? I know they pick up cancer but the word I have heard is that it only does so when blind Freddie would have also done so. I only ask not to upset people but because though I haven't been diagnosed with it, I am a prime candidate who is unlikely to find out prior to being hospitalised. Thanks. ================= hi - i'll stay with the facts. it is a fact that the prostate cell is the ONLY cell in the human body that produces psa. it is a fact that the psa test checks for a particular enzyme the prostate produces. it is a fact that in order for ANY test to be accurate, it must pass two standards. validity and is it dependable. is the test producing a valid test and check for what it is intended for? the answer is yes. is it dependable in the fact that it will produce the same result time and time again. that answer is yes. so, what do you have. you have the fact that the prostate produces psa, the psa checks for psa. ok, does that prove that you have prostate cancer. NO!! then what does it prove??? it proves that something is going on inside your body and it needs to be investigated. much like the check engine like on the dashboard on a car. it could be used as a warning sign and it is a tool to be used to help dx the final outcome. with the help of the DRE, and the psa, one gets more input and a better idea than if one was to rely on just one test alone. now....does it work? in MY particular case, i would have to say yes !!! i have a neg. DRE up to 8 hours before my surgery, yet the psa test was the alarm that triggered the biopsy and found that i have cancer in both lobes and was T2c. now, someone can say, hogwash on the psa. hey, everyone is entitled to what they believe. ~ curtis knowledge is power - growing old is mandatory - growing wise is optional "Many more men die with prostate cancer than of it. Growing old is invariably fatal. Prostate cancer is only sometimes so." http://community.webtv.net/PALMER_ENT/doc
From: ron on 15 Feb 2005 14:25 c palmer wrote...snip... > it is a fact that the prostate cell is the ONLY cell in the human body > that produces psa. Hi Curtis...This doesn't affect the points you were making, but I thought you'd be interested in knowing that other organs do produce small amounts of PSA. The name, "PSA", was given before tests were available with the sensitivity necessary to detect these small amounts of PSA. Some women produce enough PSA that it can be detetcted with the ultrasensitive PSA test, and, of course, they don't have prostates...Best wishes and good health, Ron
From: ron on 15 Feb 2005 19:16
c palmer wrote...snip... > hi ron - what i was pointing out was in the male body only. Curtis...Even the male body can produce small amounts of PSA outside the prostate...Ron Int J Cancer. 2005 Jan 10;113(2):290-7. Related Articles, Links Expression of prostate-specific antigen (PSA) and human glandular kallikrein 2 (hK2) in ileum and other extraprostatic tissues. Olsson AY, Bjartell A, Lilja H, Lundwall A. Department of Laboratory Medicine, Lund University, University Hospital UMAS, S-205 02 Malmo, Sweden. Yvonne.Olsson(a)klkemi.mas.lu.se Prostate-specific antigen (PSA) is a widely used marker for prostate cancer. In the literature, there are reports of nonprostatic expression of PSA that potentially can affect early diagnosis. However, the results are scattered and inconclusive, which motivated us to conduct a more comprehensive study of the tissue distribution of PSA and the closely related protein human glandular kallikrein 2 (hK2). RT-PCR, in situ hybridization and immunohistochemistry were used to detect expression of both PSA and hK2 in secretory epithelial cells of trachea, thyroid gland, mammary gland, salivary gland, jejunum, ileum, epididymis, seminal vesicle and urethra, as well as in Leydig cells, pancreatic exocrine glands and epidermis. Immunometric measurements revealed that the concentration of PSA in nonprostatic tissues represents less than 1% of the amount in normal prostate. Pronounced expression of PSA was detected in the Paneth cells in ileum, which prompted us to compare functional parameters of PSA in ileum and prostate. We found that in homogenates from these 2 tissues, PSA manifested equivalent amidolytic activity and capacity to form complexes with protease inhibitors in blood in vitro. Thus, PSA released from sources other than the prostate may add to the plasma pool of this protein, but given the lower levels detected from those sites, it is unlikely that nonprostatic PSA normally can interfere with the diagnosis of prostate cancer. Nevertheless, this risk should not be neglected as it may be of clinical significance under certain circumstances. |