In the continuing search for tests that will do a better job than the PSA test of defining clinically significant prostate cancer (as opposed to indolent disease) while it is still in its earliest possible stages, two new papers have provided information based on laboratory (not clinical studies).
Hermans et al. have provided additional information on the potential of the expression of the so-called TMPRSS2-ERG fusion transcripts in prostate cancer. Specifically they have shown that expression of a subtype of the transcript known as TMPRSS2(exon 0)-ERG is associated with a form of prostate cancer than has significantly less-aggressive biological behavior than expression of another subtype transcipt called TMPRSS2(exon 1)-ERG.
In the second study, Szász et al. investigated patterns of expression of proteins known as β-catenin (beta-catenin) and claudins in three different groups of patients with prostate cancer, to see if these proteins had potential as prognostic markers for more or less aggressive types of disease.
They were able to detect differences among the three groups in the expression of claudin-1, claudin-2, claudin-3, claudin-4, claudin-8, and β-catenin, regardless of Gleason score. In particular, claudin-1 and claudin-4 could be used to distinguish between those patients who had metastases and those who did not. It is therefore possible that patterns of claudin expression could be used to develop a novel diagnostic and prognostic marker for patients with prostate cancer, but there would be a lot more work needed before we could clarify this opportunity.
Filed under: Diagnosis, Risk | Tagged: catenin, claudin, Diagnosis, ERG, risk, TMPRSS2 |
THE "NEW" PROSTATE CANCER INFOLINK 
This was discussed at the 2008 Scientific Retreat for PCF. But I still wonder if we are hanging our hat on hopes for a better test, when what we truly need is a better treatment guideline — which is within reach. I am not convinced that a better diagnostic test than what PSA can deliver is realistic. Cancer is unpredictable. Let me add an extra period to that. We need better a treatment guideline and less rhetoric about screening.
In the ideal world of The “New” Prostate Cancer InfoLink, we would like: (a) less rhetoric and more sense about testing of individual patients; (b) a much better set of tests than the PSA test; (c) a much more careful discussion between doctor and patient about the risks and benefits of active treatment (based on the individual patient profile); and (d) clear and simple treatment guidelines that acknowledge the real risks and benefits of the different treatment options (from doing absolutely nothing through to the most aggressive forms of intervention). However — we shall continue to manage our actual expectations with care!