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Prostate cancer is already the most common type of cancer in men older than 45 years and the second leading cause of death among this population range. Medical check-ups from a certain age are very necessary, and this is where the latest generation of diagnostic tests that we have been adopting in our Seville clinic are becoming increasingly important.
The PCA3 gene
The diagnostic methods that have been used all these years ago to detect cases of prostate cancer were based on the determination of the PSA tumor marker, the 4kscore test and the digital rectal examination (DRE) as indicators to decide whether or not to perform a biopsy, which is an annoying, invasive and unreliable intervention.
The most widespread method (in Social Security hospitals in Spain, for example), is the PSA (Prostate-Specific Antigen), an indicator that, as we have commented on many occasions, is NOT sufficiently specific due to the fact that there are patients with elevated PSA who do not suffer from prostate cancer. The only way to rule out prostate cancer so far was with periodic biopsies.
The European Association of Urology estimates that 7 out of 10 biopsies are finally negative (i.e., the patient had given a false positive) so the international scientific community and pharmaceutical laboratories have been working for years on alternative ways of diagnosis to gain in economic savings and medical quality for patients.
Prostate biopsy in the operating room
The PCA3 gene is a prostate-specific expression gene that shows significant overexpression in prostate carcinoma cells (prostate cancer cells express 60 to 100 times more PCA3 mRNA than normal cells).
The Progensa test is highly specific for quantifying the mRNA expression of PCA3 and PSA genes in prostate cells. The determination of PSA mRNA makes it possible to estimate the amount of prostate cells in the patient sample and serves as an internal control of the sample.
The PCA3 index is calculated by applying the formula (PCA3-ARNm/PSA-ARNm)x1000. The higher the value, the greater the likelihood of finding a positive prostate cancer.
The value of 35 is taken as the cutoff for a positive biopsy result. This cutoff combines the best sensitivity vs. specificity ratio (48% vs. 79%). Values below 30 indicate a low probability of prostate cancer, being lower the probability the lower the value.
A urine test to diagnose prostate carcinoma in its early stages.
PCA3 (Prostate Cancer Gene-3) is the first highly over-expressed prostate-specific gene in tumor cells with much higher expression values than in healthy cells. That is to say, scientific teams in Nijmegen (Netherlands) and Baltimore (USA) have discovered that in prostate cancer cells this gene is more active than normal, so much so that it can be measured with the certainty that cancer exists if certain values are exceeded.
Technically, the PROGENSA-PCA3 test relies on Transcription-Mediated Amplification (TMA) to quantify PCA3 mRNA in urine samples. The result translates into a score that, assessed in the clinical context of each patient, allows the green light to be given to biopsy indications with greater safety and predictability.
Where can this test be carried out in Spain?
At the moment, its implementation is not very widespread, due to its novelty. In our centre in Seville we have just begun to offer it, and it is in the field of private medicine where it can be found most often, since the Spanish Social Security does not have it within its coverage in most autonomous communities. Its use will probably expand in the coming years due to its excellent benefits.
You can consult us without obligation about prices and procedures, we will be delighted to assist you by email () or telephone (+34 615 55 11 55).