| Beginning prostate cancer screening at a younger age and the use of lower PSA cutoffs and PSA velocity measurements might detect prostate cancer more frequently in a curable stage without over diagnosing harmless cancers
It has been speculated that since the introduction of widespread PSA testing for prostate cancer, there has been an increase in the detection and treatment of clinically insignificant tumors that would not cause disability or death if left undetected. To evaluate this issue, we reviewed our results in a large, community-based PSA screening population to determine the pathological characteristics of prostate cancers detected in our screening study. From 1989 to 2001, we enrolled 35,661 men in our longitudinal prostate cancer screening study. Data were available on 3,492 of the 3,568 men (98%) diagnosed with prostate cancer during this study period. Radical prostatectomy was performed in 2,254 men (63%). Our prospective database contained information on clinical stage, Gleason score and pathological analysis. We analyzed the association of these pathologic tumor features with preoperative PSA level, digital rectal examination findings, the PSA velocity and the year of cancer detection. Approximately 10% of men in the study were diagnosed with prostate cancer. Virtually all cases were clinically localized (99.8%) and approximately 70% treated with radical prostatectomy had pathologically organ-confined disease with negative surgical margins. However, fewer than 10% of tumors would be considered “clinically insignificant,“ based on previously published pathological criteria of Epstein et al and by Ohori et al. Our results demonstrate that, compared to the high prevalence of prostate cancer found in autopsy studies (>35% in men over the age of 50 years old), there is a lower detection rate in our screening study. Although we do not know what the outcomes would have been these tumors had not been diagnosed and treated, the majority met pathological criteria usually associated with “significant cancer” and still were organ confined and curable. However, in our study cancer was still “under diagnosed” (detected in a non-organ confined or margin-positive stage) more often (30%) than “over diagnosed” (clinically insignificant cancer) (10%). This suggests that beginning prostate cancer at a younger age and the use of lower PSA cutoffs and PSA velocity measurements might detect prostate cancer more frequently in a curable stage without over diagnosing harmless cancers.
Bibliographical reference:
William
J. Catalona
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