Tag Archives: psa values

Dear Abby, my PSA…


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If you are a reader of this blog, it is likely that you or a close friend/relative has dealt with or are dealing with prostate cancer. Hence, you have become the “expert” in your family or book club or similar for people who know your story. One of the most frequent questions I encounter in such circumstances is a question about someone’s recent PSA. As an example, an 86 year old otherwise healthy cardiologist recently called me asking what to do about his  PSA that had gone from 4-ish to 6-ish during the last 2 years.

There are a few generalizations that seem to apply to most of these queries. First, the PSA increases at a fairly predictable rate with age. As a crude rule of thumb, I tell patients/friends that it should be less than 2 when you are 50, less than 3 when you are 60, and less than 4 when you are 70. A recent article in JAMA illustrates this point nicely. In the PLCO cancer screening trial, 10,968 men aged 55-60 had a baseline PSA drawn and were then followed with various screening strategies for prostate, colon, or lung cancer. Among the men with baseline PSA of <0.99, the incidence of developing clinically significant prostate cancer in the next 13 years was only 1.5%, whereas if their baseline PSA was 2-2.99, the chances increased to 10.6%. The authors concluded that ” These findings suggest that repeated screening can be less frequent among men aged 55 to 60 years with a low baseline PSA level (ie, <2.00 ng/mL) and possibly discontinued among those with baseline PSA levels of less than 1.00 ng/mL.” What to do for my octogenarian cardiologist friend is more complicated, of course.

A second generalization is that if someone has chosen to follow his PSA more closely, say on an annual basis, because they have read enough about screening to feel that regardless of the controversy, they wish to do so, they should plot their data. A column of numbers is much harder to interpret than a visual graph. There is an easy way to do this by entering the data on a website like this one: Doubling-Time.  It is also important to realize that different labs may give slightly different values on the same patient – particularly challenging if one is trying to torture the data in the lowest ranges of detectability (<0.2).

Thirdly, and related to the plotting approach, for any given patient with known metastatic prostate cancer, the absolute value of PSA may be less important than the rate of change (doubling time). A rising PSA that goes from 3 to 6 in 6 months is of greater concern than someone with a PSA going from 150 to 160. Of course having a lower value generally means a lower cancer burden, but I once had a patient enjoy elk hunting during the later stages of his disease with a PSA over 2000. He had relatively few symptoms in spite of his advanced disease.

Lastly, and related to my aging cardiologist friend, there’s a lot more to know than the PSA in most cases. When I asked him what his urinary habits were (unchanged) and what his rectal exam revealed (he hadn’t had one), I suggested he should visit a urologist for a more complete picture. If you biopsied his prostate, there is probably >50% chance of finding cancer at his age, but the key question is whether it would be a “clinically significant” cancer (Gleason score >3+3=6, or multiple cores positive etc.) In addition, one now has the opportunity to do pre-biopsy tests such as Select MDx, PHI, or ExoDx with newer tests being developed all the time to try and NOT find patients with low risk disease who might never need any sort of treatment.

So, at your next cocktail party when a friend asks about PSA, you can gently explain the complexities you are all too familiar with, and hopefully guide them in the right direction. And if you are interested in more blogs, I recently discovered Snuffy Myers’ blog site, Prostapedia, that has numerous blogs from highly respected prostate experts with great ongoing updates. Happy New Year and most importantly EXERCISE!

 

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Filed under General Prostate Cancer Issues

Rising PSA – When to start therapy


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One of the most frequent situations I encounter in my small “prostate cancer only” practice is a man who has had treatment (usually surgery or radiation) several years ago and now has a rising PSA. He feels absolutely fine, may be exercising daily, and his PSA is often so low that a routine scan won’t show anything. What to do?

The options in this situation are changing. Treating oligometastatic disease (few metastases) is somewhat of a new frontier in this situation. In the “old days” when I wrote about this subject, we reviewed the non-randomized data that suggested no advantage to starting ADT earlier. More recently, the idea of treating some men with radiation or surgery directed at the mets if they have only a few has become more popular. Added to this is the increased sensitivity of the newer PET scans (choline, acetate, PSMA targeted) that may reveal metastases even with PSA values less than 1.0. While it is hoped that some men could be cured by this approach, it is also possible that one could delay the implementation of ADT and its side effects. There are multiple ongoing clinical trials looking at this issue. With such rapidly changing technology, it will be difficult to come up with a “right choice” in every situation. What may have been considered “non-metastatic rising PSA” last year could become “oligometastatic” simply by the implementation of the new scans.

Beyond this is the issue of treatment-related side effects. In an article this week in Lancet Oncology, the side effects of treating men with asymptomatic, non-curable prostate cancer (TOAD and TROG studies) was reported. This study is one of the few randomized studies in this setting. The men were about 70 years old with rising PSA’s, most having been previously treated. They were randomized 1:1 to starting ADT immediately or waiting until at least 2 years later unless “symptoms or metastases developed or PSA doubling times decreased to 6 months or less”. Earlier, the investigators published the survival data in this study, indicating some advantage to starting earlier, as shown in this graph. Screen Shot 2017-09-12 at 9.14.48 PM

However, keep in mind that the men who were in the immediate ADT arm also experienced the ADT side effects sooner according to the new report. The most important areas of symptoms were the hot flashes and decreases in sexual activity (reported only in the men who were sexually active) which were significantly worse with the immediate treatment, as might be expected. In a “global quality of life” measurement there was also worse quality of life, although it was not significant (the score number was 72.39 for delayed therapy vs. 70.83 for the immediate group). Further, the type of ADT used varied, and included both intermittent and continuous therapy (usually intermittent therapy has at least some improvement in quality of life). Finally, none of the men in these studies received the newer (and vastly more expensive -but probably more effective) ADT agents, abiraterone or enzalutamide which have been shown to improve survival when used “up front” in the metastatic setting.

Thus, a rising PSA is obviously a reason for concern, but choosing a management strategy is quite complicated at the present time. The best news to come out of this study is that prostate cancer is a slow disease. “Overall, 18 (6%) men died from prostate cancer, 12 (8%) in the delayed treatment arm and six (4%) in the immediate arm…” This is not to say that as time goes on there will not be more prostate cancer deaths, and there was earlier metastatic progression in the delayed group, but it is equally important to realize that at age 70 there will be significant competing causes of mortality. Something will get us eventually, so the key is to not let prostate cancer (or the PSA) dominate our thinking. What other things can you work on? Stop smoking. Exercise. Improve your diet. And most of all, enjoy each day as a gift and live it to the fullest regardless of how you decide to deal with a rising PSA.

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Filed under General Prostate Cancer Issues, Oligometastatic prostate cancer, Prostate cancer therapy