Annual changes in the clinical features of prostatic adenocarcinoma in Taiwan.

Abstract

To determine, using a clinical and pathological database, the annual changes in the characteristics of adenocarcinoma of the prostate diagnosed in consecutive men in Taiwan. All prostatic adenocarcinomas newly diagnosed between 1991 and 1999 in our institution were analysed. Using logistic regression for dichotomous variables, the annual trends were assessed for changes in the percentage of T1c disease, incidental carcinoma, clinically localized disease and Gleason grade 4/5 cancers. The annual trends for changes in the pathological features of disease in patients treated by radical prostatectomy were also analysed. The study included 694 patients; the median age at diagnosis increased significantly (P = 0.004) and there was a significant increase in clinical T1c disease (relative risk, RR, 1.142, P = 0.022). There were also significant decreases in incidental carcinomas (RR 0.789, P < 0.001), patients with a serum prostate-specific antigen (PSA) level of > 20 ng/mL (RR 0.848, P < 0.001) and with Gleason grade 4/5 tumours (RR 0.919, P = 0.005). There was no significant change in the percentage of clinically localized disease. Radical prostatectomy was undertaken in 179 men; the annual incidence of lymph node metastases decreased significantly (P = 0.035) and there was a significant 19% increase in the RR of having organ-confined disease (pT1-2N0M0) and a 19% decrease in Gleason grade 4/5 tumours. These results may reflect the annual trends of prostate cancer in Taiwan in the period for which the PSA assay became available. The increasing application of PSA testing was associated with a significant increase in clinical T1c disease and decrease in incidental carcinoma. There was also a significant trend towards less aggressive cancers. Despite the dramatic increase in the annual detection rate, tumours were not detected at an earlier stage. However, for patients treated with radical prostatectomy, there was a significant change to earlier stage disease and fewer de-differentiated cancers.