Sampling in prostate cancer
The German Association of Urology congress in 2009 had to offer six new studies on prostate biopsy. Subjects were in particular the accuracy of the prediction of not requiring treatment or localized tumors as well as the saturation biopsy.
The Partin tables were the subject of the first study (Diedrich). They can be used on the basis of clinical stage (T1c to T2c, see for TNM system growth and spread of prostate cancer ), theGleason score and the PSA value to predict the probabilities of an organ-confined tumor, capsule-over and seminal vesicle invasion. The analysis of data from 938 patients after radical prostatectomy showed that the prediction accuracy for organ limitations and exceeding the capsule increased with the number of samples taken. However, the prediction for a seminal vesicle invasion was not accurate.
The detection not requiring treatment (insignificant) tumors by tissue biopsy is still difficult. In a German study (Musch) were before and after surgery, in contrast to the U.S., only a few do not require treatment recognizable tumors (4.1% and 6.8% respectively). The match was so bad that on the basis of so-called Epstein criteria of 2004, only a single tumor before surgery would have been correctly classified.
The prediction for a unilateral, localized tumor is apparently also difficult: In a study (bird) on 243 men with a tumor with low risk (low risk: T1c or T2a, Gleason score to 6, PSA less than 10ng/ml; Moreover, a maximum of 2 infected biopsy samples on the same side) turned after radical prostatectomy for almost two thirds of patients a double-sided or capsule-border growth out. The prediction for a unilateral, localized tumor spread was by PSA, free PSA (see PSA test), T stage, prostate volume and number of pathological biopsy cylinder not possible. These uncertainties should be considered when a limited to a page treatment stands for election.
Another study (Waldert) dealt with the question of which factors increase the likelihood that the Gleason score must be corrected after prostate surgery upwards (upgrading). From 1470 men after multiple biopsy and radical prostatectomy an upgrading was necessary in 49% after 6-biopsy, at 37% after 8-fold biopsy and 24% according to the extended biopsy. Independently of each other, it was also more likely in low prostate volume, high PSA level, lower number of diseased samples and low Gleason score in the biopsy.
That means Saturationsbiopsie (saturation biopsy with at least 20 samples after previous negative biopsy) was discovered less and less prostate cancer in recent years, was found in Austria (Kunit). Such had received 560 men who had been previously biopsied at least twice and in which the PSA level had increased or increased or the DRE (see also DRU ) had changed. The detection rate of prostate cancer was from 2001 to 2003 about 40%, from 2006 to 2008, however, only just under 25%.
To avoid unnecessary extended biopsies (Saturationsbiopsien), a nomogram was developed on the basis of 540 such examinations after at least one previous negative biopsy (Balzer).This can be determined to discover in the Saturationsbiopsie prostate cancer probability. The nomogram applies to the following parameters: patient age, prostate volume, PSA, free PSA, number of previous biopsies and presence of ASAP (atypical mikroazinäre proliferation, suspicious tissue) in the previous biopsy. Lack of meaningfulness are not included palpation and the presence of a HG-PIN (high-grade prostatic intraepithelial neoplasia, precancer) in the previous biopsy.
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