Use of Serum PSA in Comparison of Biopsy Gleason Score with Radical Prostatectomy Gleason Score

Kim, Choung Soo; Park, Minsu; Chung, Han; Kim, Taehyo; Hong, Jun Hyuk; Park, Hyungkeun; Chung, Jinsoo; Park, Ro Jung; Park, Taehan; Ahn, Hanjong

Abstract

PURPOSE: The Gleason score of needle biopsies of the prostate and preoperative serum level of prostate-specific antigen(PSA) are two useful factors in predicting the final pathological staging of patients with prostate cancer treated by radical prostatectomy. Unfortunately, the Gleason score of the biopsy cores often differs from the Gleason score of radical prostatectomy specimen. We evaluated the role of Gleason scores of biopsy cores and the influence of PSA in predicting the Gleason scores of prostatectomy specimens and final pathological staging.
MATERIALS AND METHODS
The records of 52 patients with prostate cancer treated by radical prostatectomy from June 1990 to June 1997 were reviewed. The patients were divided into three groups according to the sum of the Gleason scores, i.e. well differentiated(Gleason score 2-4), intermediate(5-7) and poorly differentiated tumors(8-10). The concordance between Gleason score of biopsy and prostatectomy specimen was analysed according to the Gleason score of tumor in biopsy specimen. Furthermore, we evaluated the different level of PSA could affect the concordance rate between Gleason scoreofbiopsyandprostatectomyspecimen.
RESULTS
In well-differentiated tumors(Gleason score 2-4) in biopsy specimen, the concordance rate was 55.6%, In intermediate(5-7) differentiated cancers the Gleason score remained the same in 68%. In poorly differentiated tumors, the concordance rate was 72.2%. When PSA was less than 10ng/m1, concordance rate of well differentiated tumors and poorly differentiated tumors was 75%, 40%, respectively. Whereas the concordance rate of well differentiated tumors was 50% and that of poorly differentiated tumors was 90% when the PSA was higher than 20ng/m1. Using linear regression analysis, the preoperative PSA highly correlated with radical prostatectomy Gleason score(correlation coefficient(r)=0.38, p =0.005).
CONCLUSIONS
The Gleason score of prostatectomy specimen was upgraded in 44.4% when the biopsy Gleason score was well differentiated, especially when preoperative PSA was higher than 20ng/m1. Therefore, the significance of biopsy Gleason score in the clinical application must be used cautiously when it is used to predict the pathological stage or biological potential of the cancer especially when it is low Gleason score with high PSA( > 20ng/m1). In the meantime, the level of PSA plays an significant role in determining organ confined disease, while high Gleason scone reflect the Iymph node positive disease.